Is Thumper Oil really required?

I have talked to several guys that do not use motorcycle oil in their thumpers. They use automotive oil, as long as it is not the "energy conserving type" (contains friction modifiers) it is okay. I would like to save money but not at the expense of my engine. What do you folks say?

It has been talked to death. Don't do it if you are nervous. I do it pretty regularly(use auto oils). No clutch problems with Mobil 1 products of any kind. If they have the weight you want use it and smile.

On engines where I can live with 15-40 I use diesel motor oils. I have them in quanities anyway. Also they have some of the metals such as zinc that are gear friendly. Cars don't need it anymore and it is hard on catalytic converters.

But if you are nervous by the motorcycle specific oils.

I have used the 15-40 diesel oil in my bike, I tend to burn a lot of oil when using it, I currently use the 15-50 Mobil one and have no troubles,

something about gears meshing ,breaking down the oil molecules.motorcycle oil has additives to prevent this,car oils dont.Just buy the cheapest motorcycle oil you can find and change it often.It's way cheaper than rebuilding a thumper motor. :)

something about gears meshing ,breaking down the oil molecules.motorcycle oil has additives to prevent this,car oils dont. :)

I used regular oil in my XR600 and never had a problem until I went to rebuild it. I had to replace 6 transmission gears @ $100 each. Now I use only four stroke motorcycle oil in my bikes. Pay now or pay later. I do ride a lot and try to get the most out of my bikes so I use good oil and change it all the time.

Use the 4-stroke motorcycle oils. Auto oils don't have the extra additives needed to support being not only an engine oil, but also a transmission lubricant..This is important!

You can use Auto oils that are not energy conserving, but somewhere down the road, the transmission is going to suffer. I would say stick with the motorcycle specific oils simply because of the higher additive content.


This oil thing really gets some attention hey?? I have read about guys using car oils, diesel oils, bike oils geezz probably cooking oils too. It's obvious that SOME car oils work OK in bikes but why risk it when most oil companies make specific bike oils? Save what $4.00 per oil change? Think also about this, every oil company knows exactly how much car / bike/ truck oils they sell and look at this when deciding how to and where to spend promotional money. The oil industry spends millions each year on motorcycle racing and this all helps to support the whole industry, why give this away to the auto industry by purchasing auto oils? If the oil company dosen't make a motorcycle oil buy a brand that dose. How dose the saying go, "support those who support you"? As you have probably worked out I work for a motorcycle oil company and we often sponsor young kids in MX who's Mom and Dad really struggle to keep them racing. We don't care where they finish, just that they are involved with our great sport and continue to be for a long time. There are many companies who are great supporters of motorcycling be it oil or whatever. You as a consumer have the greatest power to support what you want :):D maybe this is more important than if a car oil works in a bike or not

If you're really concerned about what's going on with the oil in your engine such as how its holding up or if your gears are wearing out too quickly, etc, then get on an oil analysis program to get some hard facts about your oil choice. I'm more than comfortable with using my heavy duty motor oil based on my experiences and test results. I've also seen certain motorcycle specific oils shear down & oxidize quicker than some heavy duty motor oils, so don't assume all motorcycle specific oils are always better than everything else, but I think it's safe to say that most if not all motorcycle specific oils are good enough. You should always be safe with a name brand motorcycle oil. The only way to tell how well your oil is working for you is to have it regularly analyzed. There's always talk about which oil is the best and everyone has an opinion, but very few go the extra mile to have their oil analyzed...go figure :)

Changing the oil often (within 500 miles) for off road use goes a long ways towards keeping your engine & gearbox happy. I usually change mine within 400 miles. Don't be surprised to see dirt in your oil analysis if your bike is used primarily off road and that's a good enough reason to change your oil often. While our air filters do a fair job of keeping the air intake clean, you'll see significantly more dirt in your oil analysis if your bike is used primarily off road. Even motorcycle specific oil will shear down quickly in our bikes and you'll readily see this if you look at enough oil analysis samples whether its synthetic or not. One of the tests for shear stability that's used for JASO-MA & MB oils requires the use of a diesel injector and that should give you a little something to think about, but don't assume all diesel oils are a good choice. Formulations do change, so what's good one year may not necessarily be as good of choice next year if you plan to stray from motorcycle specific oils. JASO is the Japanese Automotive Standards Organization that developed standards for motorcycle oils similar to what the API has done for automobile oils. You can check out their web site at...

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