Figuring out the right oil to use for optimum performance of your dirt bike need not be difficult.
Just like a car, different engines from different manufacturers use different oil. The key in finding the right oil is two-fold. First, do you ride a 2-stroke or 4-stroke dirt bike? There is a big difference here not only in oil but in what you do with the oil. (Check out our 2-Stroke and 4-Stroke exhaust guides.)
Two-stroke oil is used in crankcase compression two-stroke engines. The four-stroke engine utilizes a closed crankcase. The crankcase in the two-stroke engine is used as part of the induction tract. Therefore, in a two-stroke engine you mix your two-stroke oil with gasoline - the gasoline acting as lubrication throughout the engine.
Two-stroke oil is a bit different than 4-stroke oil in that 2-stroke engine oil does not have weight indications. Additionally, two main types of 2-stroke oil exist: injector safe and pre-mix. Most dirt bikes fall into the pre-mix category that is combined with gas.
Four-stroke oil is more like the oil used in cars but both 2-stroke and 4-stroke oil serve the same purpose - to keep the engine lubricated. Four-stroke dirt bike oil comes in a variety of weights like 10w-40, 20w-50 and so on. It is not mixed with gas.
So now what oil should you use? Easy. The second key to finding the right oil for your dirt bike is: Read your owner's manual to find what oil the manufacturer recommends for your bike.
If your manufacturer recommends 20w-50 for your 4-stroke then don't buy 10w-30 weight oil. The most common weight for dirt bikes is 10w-40. Your owner's manual also explains what ratio to mix your oil and gas for the 2-stroke engine in order to get the best performance. It can be anywhere from 1:100 to 1:8 and all in between.
Always check your owner's manual for the correct weight in oil that works best with your dirt bike. Once you know what weight oil to use, then we can recommend specific brands of oil in the manufacturer's suggested weight for your machine. We carry all the different oils your dirt bike requires to run smoothly and run efficiently without breaking down.
If you're running a 2-stroke make it easy on yourself and get a measuring cup device so you can accurately measure the oil-to-gas ratio recommended by the bike's manufacturer. Here are some recommendations for measuring cups.
Now for the oil.
2-stroke Oil Recommendations
4-stroke Oil Recommendations
Dirt Bike Gear Oil
If you've perused the aisles of an auto parts store or scanned our Dirt Bike Oils, Fluids & Lubrication page you may notice some oil with a viscosity weight of something like 80w-85. You'd never put that in your engine but it's exactly what you'll use in your transmission. Gear oil or transmission oil requires a higher viscosity to protect those vital parts from break-down and to cool off your clutch. A word to the wise: Don't use car transmission oil - it causes clutch failure in your dirt bike.
Again, the best gear oil for your dirt bike is found in the owner's manual.
Gear Oil Recommendations
Dirt Bike Air Filter Oil
For those new to the world of dirt bikes adding oil to your air filter may be a head-scratcher. You don't use regular engine oil for your air filter (though in a pinch you can with mixed results) instead you use air filter oil. A coat of air filter oil applied to your air filter, which is then allowed to dry, traps more dirt, debris and other engine damaging contaminants than without it.
Air filter oil serves to preserve the life of your engine by keeping the engine oil cleaner. You may also save money in the long run by needing less frequent oil changes. Air filter oil is something typically not a recommendation by the manufacturer in the owner's manual so we can definitely weigh in on as far as which air filter oil historically produces the best results.
Air Filter Oil Recommendations
Remember to always consult with the owner's manual for your dirt bike to determine the best oil for optimum performance and durability. Some owners never sway from a specific brand but they use the weight recommended by the manufacturer.
Semi-synthetic and full synthetic oils protect today's modern engines that run harder. Synthenic oils are cleaner and last longer then conventional petroleum based oil. Newer engines may require only the use of semi-synthetic or full synthetic oil, again, your owner's manual provides direction on this.
For older engines synthetic oils work, however, engines fed on a 100 percent diet of petroleum-based oil for the last 15 years, you may start to see oil leaks after using synthetic oil. This occurs when the synthetic oil cleans the sludge off the engine seals thus exposing cracks in the seals.
Written By: AndrewT