A. This question is
perhaps the most hotly contested out of any questions ever asked about the
Virago. Some say that the "wet clutch" in a motorcycle requires
special oil to withstand the greater "sheer forces" on the oil causing
it to break down faster. Others will tell you they use and have used the local
gas station's cheaper oils since they got their bikes. To solve the issue of the
personal feelings about the real facts behind the use of oil, I offer this study
on the differences between "Motorcycle
Oils" vs. "Automotive Oils"
Comments: After reading that the study cited found that Castrol GTX motoroil came in second only to the more expensive synthetic based oils, and performed better on average than the grossly more expensive "Motorcycle Oil" tested, I prefer to use only Castrol GTX 20w 40 in the Summer, and Castrol GTX 10w 30 in the cooler Spring and Fall months.
Yamaha recommends the following:
40° F and above SAE20W/40, SE-SF
40° F and below SAE10W/30, SE-SF