Common Sense Comments About Oil

Moto or auto oil? Synthtic or conventional?

Motorcycle-specific oil or automotive oil? Synthetic or non-synthetic?
Motorcycle-specific oil or automotive oil? Synthetic or non-synthetic?Photography by Mark Zimmerman

Lately the Q&A in box has been full of oil-related questions. Given that current oil prices are higher than a cat’s back, I suppose that’s to be expected. So let me give you my take on some of the issues.

As far as the basics, you’ll never go wrong using the OEM’s recommended specs, viscosity and change intervals. If your bike’s manufacturer says to use a conventional 10W40 oil with an SM rating and change it every 8,000 miles, then trust me it’s all you’ll have to do under normal circumstances to keep your engine alive and well. Obviously the catch here is “under normal circumstances.” If the bike is ridden under severe conditions, which can mean almost anything from riding on a dusty road, or through the winter, to racing the bike, than you’ll have to adjust the change interval accordingly.

Another biggie concerns the use of dedicated motorcycle oils versus over the counter “automotive oils.” While I’m sure I’ll take a beating over this one, I’m going to tell you that in over 45 years of riding, I’ve experimented with just about every available type of oil, and in general have had very good luck using non-motorcycle-specific oils in my bikes. This isn’t to say the dedicated motorcycle oils are bad. Let me make it perfectly clear that they aren’t and in some very specific instances or conditions may work better than something you’ve purchased down at the local auto parts store. But for general use I have a hard time justifying their expense compared to any premium grade automotive oil. I’d also suggest that the general use oils are available just about everywhere, which is an important point when you’re touring and decide to do a quickie oil change in some campground or motel parking lot, or just need a quart of 10-W40 to top off the tank on a Saturday night.

Let me state unequivocally that synthetic oils are the best thing to happen to the internal combustion engine since the introduction of the cam operated intake valve.

Probably the biggest controversy surrounds the use of synthetic oil. Let me state unequivocally that synthetic oils are the best thing to happen to the internal combustion engine since the introduction of the cam-operated intake valve. Synthetics provide great protection, extend the change interval, and in some cases even free up a little horsepower and increase your mileage. Hell, for all I know they might even help whiten your teeth and freshen your breath, but as usual there’s a catch. Synthetic oil is expensive. If you’re using it to extend your change interval, something that I find perfectly acceptable, than the cost is offset by the reduced need to change the oil. But if you’re switching over to a synthetic and still plan to change the oil every 2,000 miles, then frankly, unless there is some other compelling reason to use the stuff, you’re wasting your money.

So here’s the bottom line: In the main, conventional motor oils work just fine, especially when you follow the OEM’s recommendations regarding viscosity, grade and change intervals. If you prefer using a dedicated motorcycle oil then by all means do so, but don’t be misled into thinking that it’s an absolute requirement or that over-the-counter oils are inferior. Lastly, synthetics work great and I highly recommend them, but they are expensive, and in some cases may not be cost effective.