ENGINE OIL

i've been using synthetic for 2 years. the issue is, it cannot have friction modifiers or they will negatively affect the way the clutch grabs, since the tranny is using the same oil. i find that the engine runs much cooler with the synthetic oil - my fan hardly kicks on anymore. it used to run most of the time, since it's mostly mountains here. i use Shell Rotella T 5W40, but i think there are other brands (amsoil, etc.) that will work, also.

the other issue with going from conventional oil to a synthetic is you must have done scheduled oil changes and not allowed the engine to have built up excessive sludge. i used to work for mobil oil when mobil 1 was one of the first synthetics on the market. we would get complaints of oil leaks once people changed to a synthetic oil. here is the problem: if conventional oils aren't changed regularly and they build up sludge, it will begin to eat through the gasket material. this isn't a problem since it basically seals the leak with the sludge. but, once a synthetic is introduced, it will clean up the sludge left behind and a leak will develop. so, if you haven't changed oil at regular intervals, or if you aren't sure of the maintenance history of a used quad - i wouldn't suggest changing over to a synthetic. but if you have done the oil changes regularly, a synthetic should greatly extend the life of the engine. just be sure to find an oil without friction modifiers or the clutch will slip. i'm not sure about the automatic trannys and how the oil would affect them, though.

from what i've read, the shell rotella t synthetic is one of the only readily available (wal-mart, etc.) oils without the addition of friction modifiers. i found several websites awhile ago that debated the use of synthetics & after checking into the long term / high mileage / high abuse reviews, i decided to use it myself. that was 2 summers ago. i've been using it in my foreman, as well as my son's bayou (...i can explain, really - LOL) with no regrets. i can't say that i know of any real performance gains, but the fan runs alot less & the oil still has alot of "elasticity" left when i drain it. i guess elasticity isn't the right word, but when you pinch a drop between your thumb and finger, then slowly open them, the synthetic "stretches" farther before separating into 2 drops. anyways, anybody using synthetic gear oil in the diffs? i had to drag my friends bayou for miles out of the woods when he let his rear diff go dry. got so hot we couldn't get (what was left of) the ring & pinion out - kawasaki dealer said they broke their tool trying! i still bust his balls saying "the guy said he broke his tool in your rear end!" sorry, i was askin' if any body uses synthetics in their diffs...