What does the oil grade mean

8 replies to this topic
  • chrisgg90

Posted February 28, 2008 - 06:45 AM


What does the oil grade mean IE 0w40 10w50 10w60 ect. Just trying to figure out what oil to use in my new bike the 0w40 is the most expensive stuff.

  • SMITH201

Posted February 28, 2008 - 07:01 AM


a 0W or 5W would be used in colder temps. 10W is the most common mid range used.


  • mxmx0606yzf

Posted February 28, 2008 - 07:02 AM


the different numbers represent the oils' weight, different oil weights are used to compensate for a few things, tempature being one of them. in colder weather you can run a little lighter oil, in hot weather the opposite....i dont know the climate is like in the uk but in general 10w40 is very all purpose. you should check the owners manual or call your local bike shop and see what each recommend....or do a search on here in the KTM forum about oil, good luck

  • 4ever2strokes

Posted February 28, 2008 - 07:03 AM


Multi-grade motor oilThe temperature range the oil is exposed to in most vehicles can be wide, ranging from cold ambient temperatures in the winter before the vehicle is started up to hot operating temperatures when the vehicle is fully warmed up in hot summer weather. A specific oil will have high viscosity when cold and a low viscosity at the engine's operating temperature. The difference in viscosities for any single-grade oil is too large between the extremes of temperature. To bring the difference in viscosities closer together, special polymer additives called viscosity index improvers, or VIs are added to the oil. These additives make the oil a multi-grade motor oil. The idea is to cause the multi-grade oil to have the viscosity of the base number when cold and the viscosity of second number when hot. This enables one type of oil to be generally used all year, and when multi-grades were initially developed, they were frequently described as all-season oil. The viscosity of a multi-grade oil still varies logarithmically with temperature, but the slope representing the change is lessened. This slope representing the change with temperature depends on the nature and amount of the additives to the base oil.

The API/SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. Historically, the first number associated with the W (again 'W' is for Winter, not Weight) is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W". "0W" can be pumped at a lower temperature than "5W", and thins less at temperatures above 99°C (210°F). The second number, 30, means that the viscosity of this multi-grade oil at 100°C (212°F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. This "classic" method of defining the "W" rating has since been replaced with a more technical test where a "cold crank simulator" is used at increasingly lowered temps. A 0W oil is tested at -35°F, a 5W at -30°F and a 10W is tested at -25°F. The real-world ability of an oil to crank in the cold is diminished soon after put into service. The motor oil grade and viscosity to be used in a given vehicle is specified by the manufacturer of the vehicle (although some modern European cars now make no viscosity requirement), but can vary from country to country when climatic or mpg constraints come into play. Oil circulates through the piston oil rings to cool and lubricate the compression rings. Inside gasoline engines, the top compression ring is exposed to temperatures as high as 500°F.

Many new vehicles are marked to use 5W-20 oil (Honda, Ford, and more recently Toyota) which is not much thinner than a 30 weight oil. Nay-sayers of 20 weight oil's ability to protect engines should note that typically, 30 weight oils shear down into the 20 weight range anyway. Most engine wear is during start-up and warm-up period, where the thinner 20 weight oil's flow is desirable. Overall, lab test results of the wear metals contained in used oil samples show low or lower wear with 20 weight than 30 in applications it is specified for. Some ultra fuel efficient and hybrid vehicles are marked to use 0W-20 oil. For some selective mechanical problems with engines, using a more viscous oil can ameliorate the symptoms, i.e. changing from 5W-20 to 20W-50 may eliminate a knocking noise from the engine but doesn't solve the problem, just "masks" it. Excess amounts of oil consumed by an engine burning it can be addressed by using a thicker oil, a 10W-40 might not burn off as fast compared to a 5W-30. A newer product that also addresses this issue is the "High-Miles" oils now marketed. They tend to be slightly thick for their grades, contain extra additives and seal conditioners. Apparently the formulation of these oils works well in many instances.

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  • chrisgg90

Posted February 28, 2008 - 07:04 AM


Ktm recommend 10w50 the dealer 10w60

  • 4ever2strokes

Posted February 28, 2008 - 07:05 AM


Let's all just answer at once.:smirk:

  • mxmx0606yzf

Posted February 28, 2008 - 07:14 AM


Ktm recommend 10w50 the dealer 10w60

Theres your answer, pick one...not a lot of difference between the two

  • reconranger

Posted February 28, 2008 - 08:49 AM


Just open up your owner's manual, and run whatever the manual recommends for the ambient temperature you will be running at during that season!!!....keeping in mind it will be "global cooling" now, not global warming!

These are just generalizations, but in most of the US and Europe, 10W40 makes a good summer oil and 5W30 a good winter oil.

In the frozen north, maybe 10W30 in summer and 0W30 in winter.

In very hot climates, maybe a 15 or 20W50.

  • chrisgg90

Posted February 28, 2008 - 08:53 AM


4ever2stroke thanks for the explanation there gives me a lot better understanding of it think i'll stick with the 10w50 i was thinking the 0w40 would be better but think i'm better with the 50 than the 40 as the UK is cold but usually only -10 at most in the winter so won't need the extra cold start protection but want the extra at temp

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