All About Your Oil - NYMCC Message Board

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TOPIC: All About Your Oil

Tonys57chevy

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Date: Aug 24, 2009

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How much do you value the engine in your car? Think about it, because the life of your engine depends in no small part on the quality of the oil you put in it - oil is the lifeblood of your car's engine. From the mid 80's for 8 or 9 years there was a veritable revolution in car engine oil. All oils were no longer the same thanks to the popularity of hot hatches, 16-valve engines and turbos as the tuner scene started to rise. Combined with the devastating problems of black death, the days of one oil catering for everyone were over. Take Castrol for example. They led the field for years with GTX. This was surpassed a few years back by semi-synthetic and fully synthetic oils, including GTX2 and GTX3 Lightec. Now, that's been surpassed by Formula SLX which can cost upwards of £50 ($75) for 5 litres. And most recently, Castrol GTX Magnatec which is muscling in on the hitherto separate world of friction reducers What does my oil do? An engine oil's job is primarily to stop all the metal surfaces in your engine from grinding together and tearing themselves apart from friction whilst transferring heat away from the combustion cycle. Engine oil must also be able to hold all the nasty by-products of combustion, such as silica (silicon oxide) and acids in suspension. It cleans the engine of these chemicals and build-ups, and keeps the moving parts coated in oil. Finally, engine oil minimises the exposure to oxygen and thus oxidation at higher temperatures. It does all of these things under tremendous heat and pressure. What the heck was Black Death? Black Death first appeared in the early 80's when a horrible sticky black substance was found to be the cause of many engine seizures in Europe. Many engines were affected but Ford and Vauxhall (GM) suffered the most. Faster roads, higher under-hood temperatures, tighter engineering tolerances and overworked engine oils turned out to be contributors to the problem. The oils just couldn't handle it and changed their chemical makeup under pressure into a sort of tar-like glue. This blocked all the oil channels in the engines, starved them of lubrication and caused them to seize. I don't recommend this but you can reproduce the effect with a frying pan, cooking oil and a blowtorch. The cooking oil will heat up far quicker than it's designed to and will turn to a sticky black tar in your pan. Either that or it will set fire to your kitchen, which is why I said "don't do this". Anyway, burning kitchens aside, Black Death was the catalyst for the production of newer higher quality oils, many of them man-made rather than mineral-based. Black death for the 21st century Sludge There's a snappy new moniker for Black Death now, and it's called sludge. The cause is the same as Black Death and it seems to be regardless of maintenance or mileage. The chemical compounds in engine oils break down over time due to prolonged exposure to high temperatures and poor maintenance habits. When the oil oxidises, the additives separate from the oil and begin to chemically break down and solidify, leading to the baked-on oil deposits turning gelatinous, and that nasty compound is what is lovingly referred to nowadays as sludge. It's like black yoghurt. What doesn't help is that modern engines, due to packaging, have smaller sumps than in the "good old days" and so hold less oil. This means that the oil that is present in the engine can't hold as much crap (for want of a better word) and can lead to earlier chemical breakdown. The most common factor in sludge buildup is mineral oils combined with a lack of maintenance by the car owner combined with harsh driving conditions. But this isn't true in all cases. For some reason, a 2005 Consumer Reports article discovered that some engines from Audi, Chrysler, Saab, Toyota, and Volkswagen appear prone to sludge almost no matter how often the oil is changed. What does sludge look like? I was contacted by a BMW driver who's been having a particularly harsh time with sludge and has been discussing it on the Bimmerfest forums. He posted some images of his problem and other readers posted similarly-framed images of the same engine components in "normal" condition. Below are two of those photos. On the left is what the cam case should look like in a well maintained engine when photographed through the oil filler cap. On the right is what the same type of engine looks like when suffering sludge buildup. NO SLUDGE SLUDGE In this example, the consensus was that the sludge buildup was caused by an overheating engine, oil that hadn't been changed for 20,000 miles of stop-go city driving, a lot of cold starts and a period of about 12 months in storage without an oil change. Most of this happened before the current owner got it Curing sludge There are no hard and fast rules for curing an engine of sludge buildup. If it's really bad, flushing the engine might be the only cure, but that could also cause even more problems. If flushing the engine results in bits of sludge getting lodged where they can do more damage, you're actually worse off. It's interesting to note that some race techs have reported sludge buildup in race engines as a result of aftermarket additives being used in conjunction with the regular oil. The chemical composition of the additives isn't as neutral as some companies would lead us to believe, and combined with particular types of oil and high-stress driving, they can cause oil breakdown and sludge to appear. The lesson from them appears to be "don't use additives". When is sludge not sludge? Easy. When it's an oil and water emulsion from a leaking or blown head gasket. If this happens, you get a whitish cream coloured sludge on the inside of the oil filler cap. The filler cap is typically cooler than the rest of the cam case and so the oil/water mix tends to condense there. So if you take the oil filler cap off and it looks like it's covered in vanilla yoghurt or mayonnaise, you've got a blown head gasket. A surefire way to confirm this is if your oil level is going up and your coolant level is going down. The coolant is getting through the breaks in the head gasket and mixing with the oil. When it gets to the sump it separates out and the oil floats on top. A slightly more accurate way to check for this condition is to use a combustion leak tester, or block tester. If you're in America, NAPA sell them for about $45 (part #BK 7001006). If you're in England, Sealey sell them for about £70 (model number VS0061). Combustion leak testers are basically a turkey baster filled with PH liquid, with a non-return valve at the bottom. To use one, run your engine for a few minutes until its warm (not hot) then turn it off. Use a protective glove (like an oven glove) and take the radiator or reservoir cap off. Plug the bottom of the combustion leak tester into the hole and squeeze the rubber bulb on top. It will suck air from the top of the coolant through the non-return valve and bubble it through the PH liquid. If the liquid changes colour (normally blue to yellow), it means there is combustion gas in the coolant, which means a head gasket leak. There is one other possible cause for this yellow goop : a blocked scavenger hose. Most engines have a hose which comes off the cam cover and returns to the engine block somewhere via a vacuum line. This is the scavenger hose which scavenges oil vapour and gasses that build up in the cam cover. If it's blocked you can end up with a buildup of condensation inside the cam cover, which can manifest itself as the yellow goop inside the filler cap. VW / Audi sludge problems While the the 1.8T engines in Audi A4's, Audi TT, VW Passat, Jetta, Golf, New Bettle, are all very prone to sludge build-up, Audi/VW does not have an extended warranty for them from the factory. The factory warranty is 4 year/50,000 miles but it can be extended if purchased. Although Audi/VW now has 10,000 mile service intervals, oil changes can be done between "services", and should be done if the vehicle is driven in heavy traffic, offroad, and non-highway use. Also, Audi/ VW will only warrant an engine if the customer has proof of all their oil changes. As of 2004 I belive all 1.8T engines must use synthetic oil. So if you own one of these sludge-prone engines, what can you do? Obviously, Volkswagen Audi Group (VAG) recommends that you use only VW/AUDI recommended oil which at the time of writing is Castrol Syntec 5W-40. You should also keep up on your oil changes, making them more frequent if you drive hard or haul a lot of cargo. The most important thing for the VW or Audi owner is this: if the oil light comes on and beeps the high pitch beep that most everyone ignores, pull over and shut the engine down immediately. Many VAG engines can be saved by this procedure. Have the vehicled towed to a VAG dealer. Their standard procedure is to inspect the cam bearings; if they're not scored, the oil pan will be removed and cleaned out and all the crankcase breather hoses and the oil pickup tube will be replaced. They'll do an oil pressure test with a mechanical gauge, and hopefully will also replace the turbo lines. Finally, the turbo will be checked for bearing free-play. The VAG turbos run really hot even with proper oil and coolant supply - that's why you need a good quality synthetic in them. Toyota sludge problems For their part, Toyota have the dubious honour of having the most complaints about sludge buildup in their engines - 3,400 at the last count. At the time of writing there is a class action suit going on against them. Details can be found at www.oilgelsettlement.com Saab sludge problems For an example of sludge in a Saab 9 5 Aero with only 42,000 miles on it, you might be interested to read my case study on this engine, put together with the help of a reader. Our sludge case study. Mineral or synthetic? Mineral oils are based on oil that comes from dear old Mother Earth which has been refined. Synthetic oils are entirely concocted by chemists wearing white lab coats in oil company laboratories. For more info, see the section on synthetics further down the page. The only other type is semi-synthetic, sometimes called premium, which is a blend of the two. It is safe to mix the different types, but it's wiser to switch completely to a new type rather than mixing. Synthetics Despite their name, most synthetic derived motor oils (ie Mobil 1, Castrol Formula RS etc ) are actually derived from mineral oils - they are mostly Polyalphaolifins and these come from the purest part of the mineral oil refraction process, the gas. PAO oils will mix with normal mineral oils which means Joe public can add synthetic to his mineral, or mineral to his synthetic without his car engine seizing up (although I've heard Mobil 1 is actually made by reformulating ethanol). The most stable bases are polyol-ester (not polyester, you fool). When I say 'stable' I mean 'less likely to react adversely with other compounds.' Synthetic oil bases tend not to contain reactive carbon atoms for this reason. Reactive carbon has a tendency to combine with oxygen creating an acid. As you can imagine, in an oil, this would be A Bad Thing. So think of synthetic oils as custom-built oils. They're designed to do the job efficiently but without any of the excess baggage that can accompany mineral based oils. Pure synthetics Pure synthetic oils (polyalkyleneglycol) are the types used almost exclusively within the industrial sector in polyglycol gearbox oils for heavily loaded gearboxes. These are typically concocted by intelligent blokes in white lab coats. These chaps break apart the molecules that make up a variety of substances, like vegetable and animal oils, and then recombine the individual atoms that make up those molecules to build new, synthetic molecules. This process allows the chemists to actually "fine tune" the molecules as they build them. Clever stuff. But Polyglycols don't mix with normal mineral oils. While we're on synthetic oils, I should mention Amsoil. I originally had them down as an additive. I was wrong. I've got to say I've had no experience of the product myself so I can't vent my spleen about it. However, there is a particularly good page with a ton of info about it here. I recommend you pop over and read this and see what you think. I've been contacted by Amsoil themselves and asked to point out the following: Amsoil do NOT produce or market oil additives and do not wish to be associated with oil additives. They are a formulator of synthetic lubricants for automotive and industrial applications and have been in business for 30+ years. They are not a half-hour infomercial or fly-by-night product, nor have they ever been involved in a legal suit regarding their product claims in that 30+ year span. Many Amsoil products are API certified, and ALL of our products meet and in most cases exceed the specifications of ILSAC, AGMA etc..... Their lubricants also exceed manufacturers specifications and Amsoil are on many manufacturers approval lists. They base their claims on ASTM certified tests and are very open to anyone, with nothing to hide. It turns out that Amsoil actually have the stance that they recommend engine oil additives are NOT to be used with their products. This will become relevant later on this page, and in the additives section. They have a pretty good FAQ on the Amsoil website, which you can find here. Mixing Mineral and Synthetic oils - the old and busted concepts For the longest time, I had this to say about mixing mineral and synthetic oils: If you've been driving around with mineral oil in your engine for years, don't switch to synthetic oil without preparation. Synthetic oils have been known to dislodge the baked-on deposits from mineral oils and leave them floating around your engine - not good. I learned this lesson the hard way! It's wise to use a flushing oil first. If you do decide to change, only go up the scale. If you've been running around on synthetic, don't change down to a mineral-based oil - your engine might not be able to cope with the degradation in lubrication. Consequently, if you've been using mineral oil, try a semi or a full synthetic oil. By degradation, I'm speaking of the wear tolerances that an engine develops based on the oil that it's using. Thicker mineral oils mean thicker layers of oil coating the moving parts (by microns though). Switching to a thinner synthetic oil can cause piston rings to leak and in some very rare cases, piston slap or crank vibration. Gaskets and seals! With the makeup of synthetic oils being different from mineral oils, mineral-oil-soaked gaskets and seals have been known to leak when exposed to synthetic oils. Perhaps not that common an occurrence, but worth bearing in mind nevertheless. Mixing Mineral and Synthetic oils - the new hotness That's the thing with progress - stuff becomes out-of-date. Fortunately for you, dear reader, the web is a great place to keep things up-to-date, so here's the current thinking on the subject of mixing mineral and synthetic oils. This information is based on the answer to a technical question posed on the Shell Oil website. There is no scientific data to support the idea that mixing mineral and synthetic oils will damage your engine. When switching from a mineral oil to a synthetic, or vice versa, you will potentially leave a small amount of residual oil in the engine. That's perfectly okay because synthetic oil and mineral-based motor oil are, for the most part, compatible with each other. (The exception is pure synetics. Polyglycols don't mix with normal mineral oils.) There is also no problem with switching back and forth between synthetic and mineral based oils. In fact, people who are "in the know" and who operate engines in areas where temperature fluctuations can be especially extreme, switch from mineral oil to synthetic oil for the colder months. They then switch back to mineral oil during the warmer months. There was a time, years ago, when switching between synthetic oils and mineral oils was not recommended if you had used one product or the other for a long period of time. People experienced problems with seals leaking and high oil consumption but changes in additive chemistry and seal material have taken care of those issues. And that's an important caveat. New seal technology is great, but if you're still driving around in a car from the 80's with its original seals, then this argument becomes a bit of a moot point - your seals are still going to be subject to the old leakage problems no matter what newfangled additives the oil companies are putting in their products. Flushing oils These are special compound oils that are very, very thin. They almost have the consistency of tap water when cold as well as hot. Typically they are 0W/20 oils. Don't ever drive with these oils in the engine - it won't last. (Caveat : some hybrid vehicles now require 0W20, so if you're a hybrid driver, check your owner's manual). Their purpose is for cleaning out all the gunk which builds up inside an engine. Note that Mobil1 0W40 is okay, because the '40' denotes that it's actually thick enough at temperature to work. 0W20 just doesn't get that viscous! To use them, drain your engine of all it's oil, but leave the old oil filter in place. Next fill it up with flushing oil and run it at a fast idle for about 20 minutes. Finally, drain all this off (and marvel at the crap that comes out with it), replace the oil filter, refill with a good synthetic oil and voila! Clean engine. Of course, like most things nowadays, there's a condition attached when using flushing oils. In an old engine you really don't want to remove all the deposits. Some of these deposits help seal rings, lifters and even some of the flanges between the heads, covers, pan and the block, where the gaskets are thin. I have heard of engines with over 280,000km that worked fine, but when flushed it failed in a month because the blow-by past the scraper ring(now really clean)contaminated the oil and screwed the rod bearings. Using Diesel oil for flushing A question came up some time ago about using diesel-rated oils to flush out petrol engines. The idea was that because of the higher detergent levels in diesel engine oil, it might be a good cleaner / flusher for a non-diesel engine. Well most of the diesel oil specification oils can be used in old petrol engines for cleaning, but you want to use a low specification oil to ensure that you do not over clean your engine and lose compression for example. Generally speaking, an SAE 15W/40 diesel engine oil for about 500 miles might do the trick. The question of phosphorus. Phosphorus is the key component for valve train protection in an engine, and 1600ppm (parts per million) used to be the standard for phosphorus in engine oil. In 1996 that was dropped to 800ppm and then more recently to 400ppm - a quarter of the original spec. Valvetrains and their components are not especially cheap to replace and this drop in phosphorus content has been a problem for many engines. So why was the level dropped? Money. Next to lead, it's the second most destructive substance to shove through a catalytic converter. The US government mandated a 150,000 mile liftime on catalytic converters and the quickest way to do that was to drop phosphorous levels and bugger the valvetrain problem. Literally. In the US, Mobil 1 originally came out with the 0W40 as a 'European Formula' as it was always above 1000 ppm. This initially got them out of the 1996 800ppm jam and knowledgeable consumers sought it out for obvious reasons. Their 15W50 has also maintained a very high level of phosphorus and all of the extended life Mobil synthetics now have at least 1000ppm. How do they get away with this? They're not classified as energy/fuel conserving oils and thus do not interfere with the precious government CAFE (corporate average fuel economy) ratings. (See my section on the EPA and fuel economy in the Fuel and Engine Bible for more info on this). This also means that they don't get the coveted ratings of other oils but they do protect your valvetrain. A quick guide to the different grades of oil. Fully Synthetic Characteristics 0W-30 0W-40 5W-40 Fuel economy savings Enhances engine performance and power Ensures engine is protected from wear and deposit build-up Ensures good cold starting and quick circulation in freezing temperatures Gets to moving parts of the engine quickly Semi-synthetic Characteristics 5W-30 10W-40 15W-40 Better protection Good protection within the first 10 minutes after starting out Roughly three times better at reducing engine wear Increased oil change intervals - don't need to change it quite so often Mineral Characteristics 10W-40 15W-40 Basic protection for a variety of engines Oil needs to be changed more often So what should I buy? Quality Counts! It doesn't matter what sort of fancy marketing goes into an engine oil, how many naked babes smear it all over their bodies, how bright and colourful the packaging is, it's what's written on the packaging which counts. Specifications and approvals are everything. There are two established testing bodies. The API (American Petroleum Institute), and the European counterpart, the ACEA (Association des Constructeurs Europeens d'Automobiles - which was the CCMC). You've probably never heard of either of them, but their stamp of approval will be seen on the side of every reputable can of engine oil. The API The API classifications are different for petrol and diesel engines: For petrol, listings start with 'S' (meaning Service category, but you can also think of it as Spark-plug ignition), followed by another code to denote standard. 'SM' is the current top grade, which recently replaced 'SL' and 'SH'. 'SH' will be found on most expensive oils, and almost all the new synthetics. It's basically an upgraded 'SG' oil which has been tested more sternly. For diesel oils, the first letter is 'C' (meaning Commercial category, but you can also think of it as Compression ignition). 'CH' is the highest grade at the moment, (technically CH-4 for heavy-duty) but 'CF' is the most popular and is well adequate for passenger vehicle applications. Note about Castrol oils: Castrol have recently upgraded all their oils and for some reason, Castrol diesels now use the 'S' rating, thus completely negating my little aid-memoir above. So the older CC,CD,CE and CF ratings no longer exist, but have been replaced by an 'SH' grade diesel oil. This link is a service bulletin from Castrol themselves, explaining the situation. The CCMC/ACEA The ACEA standards are prefixed with a 'G' for petrol engines and a 'D' or 'PD' for diesel. Coupled with this are numerous approvals by car manufacturers which many oil containers sport with pride. ACEA replaced CCMC in 1996 primarily to allow for greater read-across in test programs (eg. for viscosity, viscosity modifiers and base oil). The CCMC specifications were G (1 to 5) for gasoline, D (1 to 5) or heavy duty diesel and PD1 and PD2 for passenger car diesel. ACEA though have a slightly different nomenclature they can be summarised as A for petrol, B for passenger car diesel and E for heavy duty diesel. The ACEA grades may also be followed by the year of issue which will be either '96, '98 (current) but coming soon is 2000. Full ACEA specs are: A1 Fuel Economy Petrol A2 Standard performance level A3 High performance and / or extended drain B1 Fuel Economy diesel B2 Standard performance level B3 High performance and / or extended drain B4 For direct injection passenger car diesel engines E1 Non-turbo charged light duty diesel E2 Standard performance level E3 High performance extended drain E4 Higher performance and longer extended drain E5 (1999) High performance / long drain plus American/API performances. - This is ACEAs first attempt at a global spec. Typically, these markings will be found in a statement similar to: Meets the requirements of API SH/CD along the label somewhere. Also, you ought to be able to see the API Service Symbol somewhere on the packaging: Beware the fake API symbol Some unscrupulous manufacturers (and there's not many left that do this) will put a symbol on their packaging designed to look like the API symbol without actually being the API symbol. They do this in an effort to pump up the 'quality' of their product by relying on people not really knowing exactly what the proper API symbol should look like. To the left is an example of a fake symbol - it looks similar but as long as you remember what to look for, you won't get taken by this scam. Amsoil are one of the biggest inadvertent offenders of the fake API symbol. Take a look at one of their labels here on the right. See that little starburst that says "Fuel efficient formula SL-CF"? It can say all it likes, but the fact of the matter is that this is absolutely not an API-certified SL or CF oil. That doesn't mean it doesn't perform to those levels, but for warranty purposes, this is not an API certified product. To be fair, some Amsoil products are API certified and they do have the correct labelling, but their top-tier products do not. The issue of fake API labelling and non-compliance has caused such a stir at Amsoil that they had to put an entire page up on their site dedicated to answering this particular question. You can find it here. Basically what it boils down to is money. Amsoil don't want to pay the $300,000 it can cost for an API certification of a single oil formulation, and getting API certification can limit them to single vendors for some of the raw products they use. If those vendors put their prices up or go out of business, Amsoil need to either pass the increase in price on to the consumer, or go through the whole API thing again from scratch. If this is all confusing you, then rest assured that all top oils safely conform to the current standards. What you should treat with caution are the real cheapies and those with nothing but a maker's name on the pack. Anything below about £12 ($18) for 5 litres just isn't going to be worth it. A Brief History of Time API ratings Some people have asked about the old standards, and although they're not especially relevant, some rampant plagiarism from an API service bulletin means I can bring you all the API ratings right back from when the earth was cooling. Petrol Engines Diesel Engines Category Status Service Category Status Service CJ-4 Current Introduced in 2006 for high-speed four-stroke engines. Designed to meet 2007 on-highway exhaust emission standards. CJ-4 oils are compounded for use in all applications with diesel fuels ranging in sulphur content up to 500ppm (0.05% by weight). However, use of these oils with greater than 15ppm sulfur fuel may impact exhaust aftertreatment system durability and/or oil drain intervals. CJ-4 oils are effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. CJ-4 oils exceed the performance criteria of CF-4, CG-4, CH-4 and CI-4. CI-4 Current Introduced in 2002 for high-speed four-stroke engines. Designed to meet 2004 exhaust emission standards implemented in 2002. CI-4 oils are formulated to sustain engine durability where exhaust gas recirculation (EGR) is used and are intented for use with diesel fuels ranging in sulphur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, CG-4 and CH-4 SM Current For all automotive engines presently in use. Introduced in the API service symbol in November 2004 CH-4 Current Introduced in 1998 for high-speed four-stroke engines. CH-4 oils are specifically designed for use with diesel fuels ranging in sulphur content up to 0.5% weight. Can be used in place of CD, CE, CF-4 and CG-4. SL Current For all automotive engines presently in use. Introduced in the API service symbol in 1998 CG-4 Current Introduced in 1995 for high-speed four-stroke engines. CG-4 oils are specifically designed for use with diesel fuels ranging in sulphur content less than 0.5% weight. CG-4 oil needs to be used for engines meeting 1994 emission standards. Can be used in place of CD, CE and CF-4. SJ Still current but nearly obsolete For all automotive engines presently in use. Introduced in the API service symbol in 1996 CF-4 Current Introduced in 1990 for high-speed four-stroke naturally aspirated and turbo engines. Can be used in place of CD and CE. SH Obsolete For model year 1996 and older engines. CF-2 Current Introduced in 1994 for severe duty, two stroke motorcycle engines. Can be used in place of CD-II. SG Obsolete For model year 1993 and older engines. CF Current Introduced in 1994 for off-road, indirect-injected and other diesel engines including those using fuel over0.5% weight sulphur. Can be used in place of CD. SF Obsolete For model year 1988 and older engines. CE Obsolete Introduced in 1987 for high-speed four-stroke naturally aspirated and turbo engines. Can be used in place of CC and CD. SE Obsolete For model year 1979 and older engines. CD-II Obsolete Introduced in 1987 for two-stroke motorcycle engines. SD Obsolete For model year 1971 and older engines. CD Obsolete Introduced in 1955 for certain naturally aspirated and turbo engines. SC Obsolete For model year 1967 and older engines. CC Obsolete Introduced in 1961 for all diesels. SB Obsolete For older engines. Use this only when specifically recommended by the manufacturer. CB Obsolete Introduced in 1949 for moderate-duty engines. SA Obsolete For much older engines with no performance requirement. Use this only when specifically recommended by the manufacturer. CA Obsolete Introduced in 1940 for light-duty engines. Grade counts too!The API/ACEA ratings only refer to an oil's quality. For grade, you need to look at the SAE (Society of Automotive Engineers) ratings. These describe the oil's function and viscosity standard. Viscosity means the substance and clinging properties of the lubricant. When cold, oil can become like treacle so it is important that any lube is kept as thin as possible. It's cold performance is denoted by the letter 'W', meaning 'winter'. At the other end of the scale, a scorching hot oil can be as thin as water and about as useful too. So it needs to be as thick as possible when warm. Thin when cold but thick when warm? That's where MultiGrade oil comes in. For ages, good old 20W/50 was the oil to have. But as engines progressed and tolerances decreased, a lighter, thinner oil was required, especially when cold. Thus 15W/50, 15W/40 and even 15W/30 oils are now commonplace. Synthetics can go down as far as 5W which seemed unbeatable until Castrol came up with SLX - a 0W30 formulation! 'Free flowing' just doesn't describe it! It's predominantly a workshop oil retailing at around £10 ($15) a litre, but recommended for use in places like Canada in the winter. The latest offering to this 0W30 engineering miracle comes from AMSOIL. So again: what should I buy? That all depends on your car, your pocket and how you intend to drive and service the car. All brands claim theirs offers the best protection available - until they launch a superior alternative. It's like washing powders - whiter than white until new Super-Nukem-Dazzo comes out. For most motorists and most cars, a quality mainline oil is the best. Ones which are known to be good at their job. Stuff like Castrol GTX. They're not too dear either. Don't believe the sales hype - they all perform to the same standards once they're out of the can and into your engine. Moving up a step, you could look at Duckhams QXR and Castrol Protection Plus and GTX3 Lightec. The latter two of these are designed specifically for engines with catalytic converters. They're also a good choice for GTi's and turbo'd engines. Go up a step again and you're looking at synthetic oils aimed squarely at the performance market. To get more money out of you, the manufacturers sell this stuff in smaller amounts which makes an oil change more expensive. Marine Diesels and other special considerations. Inland Marine Diesels (and certain road vehicles under special conditions) can, and do, glaze their bores due the low cylinder wall temperature causing the oil (and more importantly the additive pack) to undergo a chemical change to a varnish-like substance. The low temperature is caused by operating under light load for long periods. This is related to engine design, some engines being nearly immune to it and others susceptible. The old Sherpa van diesel engines were notorious for this problem. The "cure" such as it is, is to use a low API specification oil, such as CC. Certain engine manufacturers/marinisers are now marketing the API CC oil for this purpose under their own name (and at a premium). You'll find some modern engines where its' industrial/vehicle manual states API CF and the marinised manual states API CC/CD. {Thanks to Tony Brooks for this information.} Marine Oils. I sometimes get asked "why are marine engine oils so expensive and why can't I just use regular motor oil in my marine engine instead?". Well, the National Marine Manufacturers Association Oil Certification Committee (click here for more info) introduced a four-stroke engine oil test and standard called the 4T certification. This specification is meant to assist boaters and manufacturers in identifying four-stroke cycle engine oils that have been specially formulated to withstand the rigors of marine engine operation. The certification was prompted by the growing influence of four-stroke engines in the marine market and their unique lubrication demands. So the simple answer is that regular road-based engine oil products don't contain rust inhibitors and won't pass the 4T certification. Lakes, waterways and the sea is a lot more aggressive an environment for an engine to operate around than on land. Note : the NMMA have long had a similar specification for 2-stroke oils destined for marine use, called the TC-W3® certification. Engine Oil Shelf Life. I couldn't decide whether to put this in the FAQ or the main page, so it's in both, because I get asked this question a lot. Typically, the question is along the lines of "GenericAutoSuperStore are having a sale on WickedlySlippy Brand synthetic oil. If I buy it now, how long can I keep if before I use it?" In general, liquid lubricants (ie. oils, not greases) will remain intact for a number of years. The main factor affecting the life of the oil is the storage condition for the products. Exposure to extreme temperature changes, and moisture will reduce the shelf life of the lubricants. ie. don't leave in the sun with the lid off. Best to keep them sealed and unopened. Technically, engine oils have shelf lives of four to five years. However, as years pass, unused engine oils can become obsolete and fail to meet the technical requirements of current engines. The specs get updated regularly based on new scientific testing procedures and engine requirements. But this is only really a concern if you've bought a brand new car but have engine oil you bought for the previous car. An oil that is a number of years old might not be formulated to meet the requirements set for your newer engine. If your unopened containers of engine oil are more than three years old, read the labels to make sure they meet the latest industry standards. If they do meet the current standards, you might want to take the extra precaution of obtaining oil analysis before using them. An oil analysis will check for key properties of the oil and ensure that it still meets the original manufacturing specs. Of course the cost of getting an analysis done on old oil is probably going to outweigh going and buying fresh stuff. So it's a double-edged sword. As a general rule, the simpler the oil formulation, the longer the shelf life. The following is a guideline under protected conditions: Product Shelf Life Base Oils, Process Oils 3 years Hydraulic Oils, Compressor Oils, General Purpose Lubricating Oils 2 years Engine Oils and Transmission Oils 3 years Industrial and Automotive Gear Oils 2 years Metal Working and Cutting Oils 1 year The following are signs of storage instability in a lubricant: Settling out of the additives as a gel or sticky liquid Floc or haze Precipitates/solid material Colour change or haziness Water contamination in a lubricant can be detected by a "milky" appearance of the product. "High mileage" oils. More and more oil companies are coming out with "high mileage" oils now, some recommended for engines with as few as 75,000 miles on them. So what is a "high mileage" oil you ask? Well very generally speaking, these oils have two additives in them which are more suited to older engines. The first is normally a burnoff-inhibitor which helps prevent the oil from burning off if it gets past an engine seal into the combustion chamber. The second is a "seal conditioner", the exact makeup of which I'm not sure of, but it's designed to soak into seals such as head- and rocker-cover gaskets and force them to expand. Thus if one of the seals is a bit leaky, the seal conditioner will attempt to minimise the leak. I've not had experience of high mileage oils myself, but a few people who've e-mailed me have passed on various tales from it being the miracle cure to it making no difference at all. I think the general rule-of-thumb though should be "if it 'aint broke, don't fix it." Just because your engine has over 75,000 miles on it, doesn't automatically mean you need high mileage oil. Is the exhaust sooty or smokey? Are you noticing oil leaks? Is the engine consuming oil? If your engine is working fine, the exhaust is clean and you're not noticing any problems, my guess is that it doesn't need high-mileage oil. What about own-brands? If you can't afford the big-name players, you could look at own-brand oils. These are usually badged oils from one of the larger companies but sold without the name, they are cheaper. Check the standards and grade ratings on the pack first! The example on the right is a local store in Chelmsford in England who sell their own label oil which is bottled for them by a volume retailer. The label tells you all you need to know. Viscosity and Viscosity Index (VI). The proper viscosity is the single most important criteria of a lubricating oil. The basic performance of machinery is based on the viscosity of the lubricant. Viscosity is, if you like, the resistance to the flowability of the oil. The thicker an oil, the higher its viscosity. The chart on the right shows a rough guide to ambient temperatures vs oil viscosity performance in both multigrade (top half) and single grade (lower half) oils. Multigrade oils work by having a polymer added to a light base oil which prevents the oil from thinning too much as it warms up. At low temperatures, the polymers are coiled up and allow the oil to flow as it's low number (W number) indicates. As the oil heats up, the polymers unwind into long chains which prevent the oil from thinning as much as it normally would. The result is that at 100°C, the oil has thinned only as much as it's higher rating. Think of it like this: a 10W30 oil is a 10-weight oil that will not thin more than a 30-weight oil when it gets hot. The viscosity index of a lubricant is an empirical formula that allows the change in viscosity in the presence of heat to be calculated. This tells the user how much the oil will thin when it is subjected to heat. The higher the viscosity index, the less an oil will thin at a specified temperature. Multi-viscosity motor oils will have a viscosity index well over 100, while single viscosity motor oils and most industrial oils will have a VI of about 100 or less. Viscosity and oil weight numbers is quite a nauseatingly detailed topic. So if you're curious about why a 15W50 oil is so-called, then put on the geek shield and pop over to the Viscosity Page..... Servicing and checking For God's sake don't skimp on either of these. You can never check your engine oil too often. Use the dipstick - that's what it's there for - and don't run below the 'min' mark. Below that, there isn't enough oil for the pump to be able to supply the top of the engine whilst keeping a reserve in the sump. All oils, no matter what their type, are made of long-chained molecules which get sheared into shorter chains in a running engine. This in turn means that the oil begins to lose it's viscosity over time, and it uses up the additives in it that prevent scuffing between cams and followers, rings and cylinder walls etc etc. When this happens, fresh oil is the key. And don't worry about the engine oil turning black. It will lose it's golden-brown colour within a few hundred miles of being put in to the engine. That doesn't mean it's not working. Quite the contrary - it means it is working well. It changes colour as it traps oxidised oil, clots and the flakes of metal that pop off heavily loaded engine parts. Just don't leave it too long between oil changes. So how often should I change my oil? You can never change your engine oil too frequently. The more you do it, the longer the engine will last. The whole debate about exactly when you change your oil is somewhat of a grey area. Manufacturers tell you every 10,000 miles or so. Your mate with a classic car tells you every 3,000 miles. Ole' Bob with the bad breath who drives a truck tells you he's never once changed the oil in his car. Fact is, large quantities of water are produced by the normal combustion process and, depending on engine wear, some of it gets into the crank case. If you have a good crank case breathing system it gets removed from there PDQ, but even so, in cold weather a lot of condensation will take place. This is bad enough in itself, since water is not noted for its lubrication qualities in an engine, but even worse, that water dissolves any nitrates formed during the combustion process. If my memory of chemistry serves me right, that leaves you with a mixture of Nitric (HNO3) and Nitrous (HNO2) acid circulating round your engine! So not only do you suffer a high rate of wear at start-up and when the engine is cold, you suffer a high rate of subsequent corrosion during normal running or even when stationary. The point I'm trying to make is that the optimum time for changing oil ought to be related to a number of factors, of which distance travelled is probably one of the least important in most cases. Here is my selection in rough order of importance: Number of cold starts (more condensation in a cold engine) Ambient temperature (how long before warm enough to stop serious condensation) Effectiveness of crank case scavenging (more of that anon) State of wear of the engine (piston blow-by multiplies the problem) Accuracy of carburation during warm-up period (extra gook produced) Distance travelled (well, lets get that one out of the way) If you were clever (or anal) enough, you could probably come up with a really clever formula incorporating all those factors. However, I would give 1, 2, and 3 equal top weighting. Items 1 to 3 have to be taken together since a given number of "cold" starts in the Dakar in summer is not the same as an equal number conducted in Fargo in January. The effect in either case will be modified by how much gas gets past the pistons. What we are really after is the severity and duration of the initial condensation period. All other things being equal, that will give you how much condensate will be produced and I would suggest that more than anything else determines when the oil should be dumped. , get to the point already! Hang on a tic - if you really want the answer, there's a couple more factors you need to take account of: Crank-case scavenging (that's the clever term for sucking the nasty fumes back out of the crank-case) - or lack of it - is a crucial multiplying factor affecting all the other items listed above. As an example, the worst I've heard of was a Ford Fiesta of the mid 70s or so. It's crank-case fume extraction was via a tiny orifice directly into the inlet manifold which obviously could not handle any significant volume of crank-case fumes without upsetting the carburation. The car in question had been used almost exclusively for 5 mile journeys to/from work, shopping etc, and it had always been serviced "by the book". Despite (or because of) this, the engine was totally buggered at 40,000 miles. Alternatively you might get a car that by virtue of excellent crank case fume scavenging could tolerate many more cold starts than one without. Taking all these into consideration, my philosophy would be to totally ignore the distance and change the oil three times a year - about November, February and May. Move these dates a bit according to the severity of the winter. An average family car will do around 14,000 miles per year and about 2/3 of that will fall in the May - November period. At the end of that period, the car will have just about touched on the recommended oil change distance - but all done at reasonable temperatures and including long distance runs during vacations and good weather. During the Nov - Feb. period it may accumulate only 2 or 3 thousand miles, all low temperature starts and mostly short runs. The Feb. to May period is likely to be about the same. About 10 or 15 years ago, an article in the ANWB journal (ANWB is the Dutch equivalent of the AA - or the AAA in the American case) reached more or less the same conclusion that distance was not very important. In their case they applied this to their road service fleet, which typically once started in the morning never got cold. In effect, they hardly ever changed the oil! I seem to remember 30,000 miles between oil changes being quoted. I also seem to remember that they had some kind of water or acid indicator attached to the end of the dipstick and went by that rather than distance. That's a politician's answer - you've dodged the entire issue! Have I? I don't know how far you drive in a year, where you live, the style of your driving or anything else so I can't tell you what's right for your car. Personally, I changed the oil and filter in my 1985 Audi Coupe every 5,000 miles. It had done over 150,000 miles when I sold it, wasn't leaking and didn't consume any oil. If you must have a figure from me, then 5,000 is it. What else happens when I change the oil then? Engines pump about 10,000 litres of air for every litre of fuel consumed, and along with all that air, they suck in plenty of dirt and grit. A good air filter will stop everything bigger than a micron in diameter - everything smaller mostly just floats around harmlessly in the 0.001inch minimum thickness oil films that separate all the moving parts. Despite all of this, there will always be submicron particles that get in and there will be places in the engines oilways where they will gather. Every time you empty the oil from your sump, you're also draining this fine grit with it. Checking the oil in your engine, and topping up. Note that this section only applies to wet sump engines - the type found in most consumer vehicles. For more info on sump types, see Wet sumps vs. dry sumps below. To a lot of people, this little section could be categorised by the rearranging the words "granny eggs teaching suck your to". But you'd be surprised by the number of people that don't know how to do even this basic task. When checking the level of oil in the engine, the car should be on a level plane, and should be relatively cold. I've run into several people lately who insist in keeping the crankcase topped off completely, and they invariably check the dipstick just after shutting down the engine. Reading the oil in this way results in an erroneous reading because a quantity of oil (usually about half a litre) is still confined in the oilways and passages (galleries) of the engine, and takes some time to drain back into the crankcase. (On the image, the blue areas are where oil is likely to still be running back down to the sump). On seeing what appears to be an abnormally low level on the dipstick, these people then add more oil to the oil filler at the top of the engine. The oilways and passages all empty, and suddenly the engine becomes over-filled with oil, going way above the 'MAX' mark on the dipstick. What happens when an engine is overfilled with oil? So you topped up the engine when it was warm after getting a faulty dipstick reading, or you put too much oil in when you changed it yourself. What's the worst that could happen? Well the problem with this is that the next time the engine is run, the windage in the crankcase and other pressures generated by the oil pump, etc. place a great strain on the seal on the rear main bearing. Eventually, often much sooner than the ordinary man in the street might expect, the rear main bearing seal ruptures, and the engine becomes a 'leaker'. If you've got a manual gearbox, this means one thing: this oil goes right onto the flywheel and the face of the clutch disc. A lubricated clutch is A Bad Thing. If this still goes unnoticed, the front seal is the next to go, and the engine then becomes a 'gusher' (or to be more colourful, it starts pissing oil all over the place). As well as smothering the clutch with oil from the rear, the oil now coming from the front leak will be neatly distributed about the engine bay as it hits the front pulley - often propelling it out as far as the brake discs. At the same time as this Hollywood disaster movie is unfolding outside the engine, things aren't working out any better on the inside. As you can see from the diagram, the correct oil level is really close to the rotating crank. Overfilling will mean the crank dips into the oil and churns it into a froth. Froth is good on certain types of coffee but not good in an engine. The mixture of aerated oil will be forced into the bearings and in case you didn't know, air is not a lubricant. Typically this means that bearing damage will follow quite rapidly, especially if you are driving on a motorway. You'll know bearing damage when you get it. The engine smells like a garage mechanic cooking over an open flame and the noise coming from the engine is the sort of thing you'd normally hear in vaudeville plays when a piano is pushed down a flight of stairs. As if that all wasn't bad enough, the excess oil gets thrown up into the piston bores where the piston rings have a hard time coping with the excess oil and pressure. It gets into the combustion chamber and some of it will get out into the exhaust system unburned resulting in a nice patina of oil all over the platinum surfaces of your catalytic converter. This renders it utterly useless for good. Well, you did ask. So what's the best way to check the oil level? If your engine is cold (for example it has been parked overnight) you can check the oil level right away. The oil will have had time to settle back into the sump. Just make sure the car is level before you do. If the engine is warm or hot (after you've been driving) then you should wait for 30 minutes or so to let as much oil as possible drain back into the sump. Checking it first thing the next morning is ideal. It's worth pointing out that you should double-check your owner's manual too - some cars, like I the '92 Porcshe Carrera, require that the oil is checked while the engine is running and the oil is at temperature. Wet sumps vs. dry sumps. Almost all passenger cars, trucks and SUVs use what's called a wet sump system. If you look at the diagram above you can see the sump (or oil pan) is the lowest part of the engine. In a wet sump system, excess oil drains back into the sump when it has passed through the engine, and the oil pump then sucks it out of the sump and pumps it back to the top of the engine. The advantage of a wet sump is that it's cost effective to build and maintain and it makes oil-checking easy for the average driver. The disadvantage is that cornering and braking can cause the oil to slosh around in the sump. This can cause the oil to not cover the oil pump pickup tube, which could starve the top end of oil, or it could get deep enough in a severe cornering maneuver to bog-down the crank, which is A Bad Thing. To counter these problems, a lot of wet sumps now have baffles in them to stop the oil moving around so much, and for your average road-going consumer-level vehicle, this is a fine compromise. Dry sumps When it comes to racing vehicles, wet sumps simply have too many disadvantages. Instead, race engines typically use a dry sump. As its name implies, the sump of the engine is dry - it never fills with oil. In a wet-sump system, the sump has to be large enough to accommodate all the oil from the engine when it is turned off. In a dry sump system, that requirement is gone so the sump can be much much smaller. (In the image on the right, the right-most sump is representative of a dry sump). A smaller sump means the engine can be mounted lower down in the vehicle, which in turn lowers the centre of gravity. So how can this be? Well a dry sump system uses a remote oil reservoir or tank, and a either a second oil pump, or a single multi-stage pump. In a double pump system, one oil pump works just like a wet sump - it distributes oil to the top end of the engine, but it pulls the oil from the reservoir instead of the sump. The second pump scavenges the oil from the sump and returns it to the reservoir. In a single pump system, one pump is either a three- or four-stage pump. It has multiple circuits running off the same pump to pressurise the engine and scavenge oil back from the sump. The advantages of dry sumps for racing become obvious when you examine the design. The engine can be mounted lower in the chassis because of the shallow oil pan. The pumps typically don't run off the crank-driven belts so no engine power is sapped in driving them. The remote tank or reservoir can be pretty much any size you like and be mounted anywhere in the vehicle (usually low down again for centre of gravity reasons). There isn't oil sloshing around in the sump so you don't run the risk of bogging down the crank. For all these reasons, dry sumps are considered to be safer and far more dependable than their wet counterparts. So if it's that much better, why don't you find this system in consumer vehicles? Simple. The increased weight, complexity and cost of having larger or more pumps and a remote reservoir with all the additional high pressure oil lines involved. For a racing team, this isn't an issue, but for Toyota or Ford, adding that sort of cost and complexity to their passenger vehicles is just a no-go. Can I use car engine oil in my motorbike then? No you can't. Or at least I wouldn't recommend it.... The real answer to this question lies in the type of motorbike you own. If you own a bike with a wet clutch (ie. where the clutch sits partially submerged in the sump oil) and you dump car oil into it, all sorts of nasty things happen. Oils formulated for car engines have friction modifiers in them. When the engine oil gets into the clutch, the friction modifiers get to work and you'll end up with a clutch that won't bite. In addition, the chemical makeup of some car oils has been known to soften the clutch material on motorbikes to the point where the entire clutch pack fails. Bike oils generally don't have friction modifiers, so they don't have this problem. If you're not sure, check for a JASO MA spec on the bottle. If you see that on the label, then it means the oil has been tested and confirmed to work with a wet clutch. Mobil have cautionary information on exactly this subject on their Motorcycle Oils FAQ page. The other side of this coin is if you have a dry clutch bike, like some BMWs. In this case, the clutch is configured similar to a car in that it's never in contact with the engine oil, and if that's the case, then regular car engine oil might provide all the protection and lubrication you need for your bike. The issue then becomes a question of the exact formulation of the oil. The additive packages for car engine oil are typically balanced differently than those for motorbikes with fuel economy and emission system protection being the higher priorities. Your typical passenger car doesn't rev to 12,000 rpm either so stuffing normal car engine oil in a motorbike engine that can run to double or even triple the rpm of a car engine could cause all sorts of problems. The debate about whether any of this is true is burning in many forums across the internet. One site in particular casts some doubt on the issue, claiming the only difference between car and bike oil is the price. I don't subscribe to that theory but in order for you to make your own decision, here's a link: Testing motorcycle oil. Sulfated ash There's a second good reason you shouldn't use car oil in your motorbike - sulfated ash. It's common in many American & Canadian modern oils; without burnt oil discoloring it, it normally has a light-gray to pale-tan colouration which may become visible if you shear a bit of the debris. When coloured by oil, it looks like the dreaded sludge. Unfortunately, the API SH-SL ratings are not strict enough on sulfated ash content. It's an issue that's fairly well known in some motorcycling circles, and the Japanese motorcycle industry recognized the issue very early on, creating a new oil specification specific to their needs (one, that among other things, caps the sulfated ash content very low): JASO-MA, recently revised further into to JASO-MA1 & JASO-MA2. For motorcyclists, the sulfated ash content poses a secondary issue: it means higher quantities of sulfuric acid if water gets introduced into the oil (such as from condensation within the galley spaces); since most motorcycle engines share the oil with both the engine and the transmission, the sulfuric acid is particularly problematic as the metals used in the transmission selector forks are made of cheaper steels that don't stand up to the acid nearly as well as most engine components. Can I use diesel engine oil in my petrol engine? Not really. Diesel engines run much higher compression ratios than petrol engines and they run a lot hotter, so the oil is formulated to deal with this. Plus they produce a lot more dirt in terms of combustion by-products. Diesel-rated oils typically have more detergents in them to deal with this (see Using Diesel oil for flushing above). It's not unheard of for diesel oils to clean a petrol engine so well that it loses compression. Diesel-rated oils also have an anti-foaming agent in them which is unique to diesel engines, and not needed in petrol engines. __________________ Pres. WICKED RIDES car club www.wickedridesnj.com www.wickedmontes.com

twomanymontes

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UGGGGH Why did they show a BMW???? I have one apart at the shop! I hate those cars!!! __________________ There is no such thing as Too Many Montes Member of the Motley Cruisers Car Club

Tonys57chevy

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they were thinking of you __________________ Pres. WICKED RIDES car club www.wickedridesnj.com www.wickedmontes.com

twomanymontes

Moderator - Monte Hunter Lead Investigator

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Date: Aug 28, 2009

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Yeah right! I'm just glad that car is done!!! __________________ There is no such thing as Too Many Montes Member of the Motley Cruisers Car Club

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