CAUTION WHEN CHOOSING OIL

[flynrider]

I have read that you should avoid using oils that are blended for higher gas mileage. I used to be an oil fanatic, using the very best oils and changing at very short intervals. As I got older, I started using good API rated motor oils like Pennzoil or Rotella and have never had a problem with many different bikes. I typically change about every 3000 miles. I have read suggestions to use oils blended for motorcycles, as they have additives for the transmission gears but I have never had a transmission or clutch problem when using car oil. For very high revving bikes, I do use oils blended for high performance engines. On another point, I have read that viscosity modifiers are rarely effective for more than about 20 points over time, so 10W30 probably is effective but 10W50 or 15W60 is probably a waste of money.

The suggestions for motorcycle oils is primarily to avoid friction modifiers that are becoming more prevalent in automotive oils. Bikes with wet clutches have the friction plates immersed in engine oil and you can get some slippage with certain friction modifiers. It used to be safe to just avoid automotive oils with the "energy conserving" stamp in the API circle, but later API specs (such as SM) allow for friction modifiers without the "energy conserving" label.

There is a Japanese specification that is specifically for motorcycles with wet clutches. JASO-MA is the spec and most motorcycle oils (and some automotive oils) are compliant.

I used to use automotive oils until the API SM spec (which does not make allowances for wet clutches). Since then I've used whatever complies with JASO-MA.