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More Than You Ever Wanted to Know About Motor Oil by Ed Hackett Choosing the best motor oil is a topic that comes up frequently in discussions between motorheads, whether they are talking about motorcycles or cars. The following article is intended to help you make a choice based on more than the advertising hype. Oil companies provide data on their oils most often referred to as "typical inspection data". This is an average of the actual physical and a few common chemical properties of their oils. This information is available to the public through their distributors or by writing or calling the company directly. I have compiled a list of the most popular, premium oils so that a ready comparison can be made. If your favorite oil is not on the list get the data from the distributor and use what I have as a data base. This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc. Viscosity is a measure of the "flowability" of an oil. More specifically, it is the property of an oil to develop and maintain a certain amount of shearing stress dependent on flow, and then to offer continued resistance to flow. Thicker oils generally have a higher viscosity, and thinner oils a lower viscosity. This is the most important property for an engine. An oil with too low a viscosity can shear and loose film strength at high temperatures. An oil with too high a viscosity may not pump to the proper parts at low temperatures and the film may tear at high rpm. The weights given on oils are arbitrary numbers assigned by the S.A.E. (Society of Automotive Engineers). These numbers correspond to "real" viscosity, as measured by several accepted techniques. These measurements are taken at specific temperatures. Oils that fall into a certain range are designated 5, 10, 20, 30, 40, 50 by the S.A.E. The W means the oil meets specifications for viscosity at 0 F and is therefore suitable for Winter use. Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot. Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best. Flash point is the temperature at which an oil gives off vapors that can be ignited with a flame held over the oil. The lower the flash point the greater tendency for the oil to suffer vaporization loss at high temperatures and to burn off on hot cylinder walls and pistons. The flash point can be an indicator of the quality of the base stock used. The higher the flash point the better. 400 F is the minimum to prevent possible high consumption. Flash point is in degrees F. Pour point is 5 degrees F above the point at which a chilled oil shows no movement at the surface for 5 seconds when inclined. This measurement is especially important for oils used in the winter. A borderline pumping temperature is given by some manufacturers. This is the temperature at which the oil will pump and maintain adequate oil pressure. This was not given by a lot of the manufacturers, but seems to be about 20 degrees F above the pour point. The lower the pour point the better. Pour point is in degrees F. % sulfated ash is how much solid material is left when the oil burns. A high ash content will tend to form more sludge and deposits in the engine. Low ash content also seems to promote long valve life. Look for oils with a low ash content. % zinc is the amount of zinc used as an extreme pressure, anti- wear additive. The zinc is only used when there is actual metal to metal contact in the engine. Hopefully the oil will do its job and this will rarely occur, but if it does, the zinc compounds react with the metal to prevent scuffing and wear. A level of .11% is enough to protect an automobile engine for the extended oil drain interval, under normal use. Those of you with high revving, air cooled motorcycles or turbo charged cars or bikes might want to look at the oils with the higher zinc content. More doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high. High zinc content can lead to deposit formation and plug fouling. The synthetics offer the only truly significant differences, due to their superior high temperature oxidation resistance, high film strength, very low tendency to form deposits, stable viscosity base, and low temperature flow characteristics. Synthetics are superior lubricants compared to traditional petroleum oils. You will have to decide if their high cost is justified in your application. The extended oil drain intervals given by the vehicle manufacturers (typically 7500 miles) and synthetic oil companies (up to 25,000 miles) are for what is called normal service. Normal service is defined as the engine at normal operating temperature, at highway speeds, and in a dust free environment. Stop and go, city driving, trips of less than 10 miles, or extreme heat or cold puts the oil change interval into the severe service category, which is 3000 miles for most vehicles. Synthetics can be run two to three times the mileage of petroleum oils with no problems. They do not react to combustion and combustion by-products to the extent that the dead dinosaur juice does. The longer drain intervals possible help take the bite out of the higher cost of the synthetics. If your car or bike is still under warranty you will have to stick to the recommended drain intervals. These are set for petroleum oils and the manufacturers make no official allowance for the use of synthetics. Oil additives should not be used. The oil companies have gone to great lengths to develop an additive package that meets the vehicle's requirements. Some of these additives are synergistic, that is the effect of two additives together is greater than the effect of each acting separately. If you add anything to the oil you may upset this balance and prevent the oil from performing to specification. The numbers above are not, by any means, all there is to determining what makes a top quality oil. The exact base stock used, the type, quality, and quantity of additives used are very important. The given data combined with the manufacturer's claims, your personal experience, and the reputation of the oil among others who use it should help you make an informed choice.

Hi everyone, Dunno if this question has been asked before, but is there a sure way to tell whether it is time for a battery change before the battery completely fails on you? Measure with voltmeter across the terminals?

whether the new car we are purchasing is a test drive's unit? Any bros here can advise? Regards

Anyone know where to buy a lancer '00 grill at a good price let's say below $200??

http://www.tirerack.com/tires/tiretech/tiretech.htm http://www.tirerack.com/wheels/tech/wheeltech.htm

Did you ever wonder where the name "Volvo" came from? A prominent Gothenberg family, perhaps? Or, just a strange Scandinavian word like "lutefisk?" Neither. It means, simply, "I roll" in Latin. I shamelessly plagiarised this from somewhere.

I want one! Anyone knows one around Singapore?

Hi, This might not be something new. But a few of us were talking about it the other night and was wondering how people get to knows about MCF. Thanks.

My one week old rim was scratch when my sis kiss the curb, sob... feels stupid to replace the rim as its only one week old... i heard of tyre shops that do recondition of rims... i jus need a touch up... any ideas where can i get this service?

Again, just to double confirm about this doubts i have. From auto magazines and other sources, i understand that upgrading your rim needs to take note of the sixe of tyre.... These are the informations i got: 1 inch u upgrading, gotta add 20mm to the width, and subtract 10 from the height. eg: 165/60R14 = 185/50R15 = 205/40R16 and so on..... inorder not to put strain on your drive train. Another thing is the speed limit for your tyre. Its written on your tyre: Q = 160 km/h S = 180 km/h T = 190 km/h H = 210 km/h V = 240 km/h W= 270 km/h Any comments? Isit reliable?

I was told that the cigarette socket is always 'on' unlike others(to my limited knowledge). Why?

I wana know if anyone can tell me the difference between the skyline GTR R32, GTR R33, and GTR R34. I can't really find much info on them except they all use the same engine, but not much else is said.... help would be nice.... tnx....

I know in the market there are 3 main types of rims in general. The one piece, two piece and three piece. Other than the fact that the three piece and two piece rims come apart (therefore if one part of the rim is damage one only needs to buy the damage part and not a whole new rim) and cost more than a 1 piece rim; What are the advantages do the 2/3 piece rim have to a 1 piece rim?

Hi! there, everyone, Read all you can about your car. Not just the driver's handbook, which some don't, but road tests as well. It'd let you know a good deal about what to expect when you drive it. Bear in mind that road test figures are done in controlled conditions, making allowance for speedometer error, wind and so on. So don't expect to emulate them all on the road. Make regular checks on your car's condition, on the tyres for tread depth, cuts & pressures, on fluid levels, lights, and keep all windows, especially the windscreen clean. Keep your car properly serviced, the harder you drive the more reliance you put on your car's mechanical parts. Rgds Paul Yong

hi all... i am running an alpine HU with an alpine 4 channel amp with a pioneer sub-woofer and JBL 4-way 6x9 speakers behind... the front is an old set of JBL 2-way speakers and tweeters installed oso... my problem is... the system can deliver bass and clarity... but the sound quality is very "hollow"... anybody has any idea why...?

Hi hi! Saw this T4 on the road with excellent dish wheels. Very nice. Noticed that it uses 4 bolts. Hoping that the PCD is 100 so that I can use them on my ride Anyone? MrCaddy http://vwcaddyclub.com