The is a topic that is continually being debated. Synthetic oil is without question a superior oil. Anymore, for the price difference, I also run synthetic oil in everything I own. For superior protection, I think the small difference in price is worth. Just be careful to use an oil that is rated for wet clutch use. Many ATV owners use Rotella T6 in their machines because it does specify "approved for wet clutch use". Or use an ATV/motorcycle specific oil. Other oils can be used as long as they don't contain friction modifiers or say "energy conserving".