Even though it seems conditional, the word "can" is loaded because it lumps all synthetics together. There are three major different types of synthetics (group III like Rotella, group IV PAO's like Mobil 1 or Amsoil, and group V which includes the esters), and there is nothing very similar about any of them!

I didn't read his posts closely, but I didn't notice that Scooby mentioned any particular brand of synthetic he had a problem with, so he is again doing us all a diservice by lumping them all together.

I also noticed that Scooby endorsed JASO MA oils for proper clutch function, WHICH ALL THE MOTORCYCLE SPECIFIC SYNTHETICS ARE (with the exception of Honda HP4M synth blend which is JASO MB, and not for use with a wet clutch).

 

Use Castrol GTX 5W/30 for $1.60 qt.
According to a district rep for Castrol the oil makers had trouble in the '90's with 5/30 oils causing foam and gelling up in a lot of engines that required that grade of oil. Most were Toyota and Nissan V-6 engines. The solution was to go to synthetic oil in a regular oil bottle.

Buy a quart of each, petroleum and synthetic and test for yourself.

look at color, check smell, taste, flow point, boil point, flash point. Use GTX 5/30, Put oil in freezer with another oil in 10/30 overnight, next day pour out oil in pan and see which flows the best. use a stove or burner outside in a safe place. Use a old pan and heat each oil with a temp probe in the oil. Check boil point and flash point. Both are the same.

I use Rotella in my Diesel truck in summer and Synthetic Rotella in winter, but when used in my boat 262 cu in Chevy engine it foamed up when I used it. Higher continuious rpm?

 

handycap: both are not the same in any of those tests. (except maybe the taste test). try any one of those tests. the syn oil will stay liquid at low temps that will jell fossil oils. and syn oil will stay liquid at high temps that leave fossil oils a charred mess in the pan. flash point of the syn oils is a lot higher too. just ask anyone with a waste oil heater that has tried to burn the used synthetic.

i'm not saying that either is better in a quad. i have run Mobil 1 V-twin oil in my harley engine, trans, and primary case (with wet clutch) for the last 30,000 miles with no problems despite the fact that the oil temps exceed 250 degrees f when i run it hard on a hot day. sometimes all day long, and this is with an oil cooler on the bike.

many of the anti friction and anti wear additives are the same in both oils as they must be added in the right amounts and any differences in them are due to each company having their own "secret recipe" for the additives.

i may or may not run synthetic in my Brute. i don't know yet. my research into synthetics so far has been looking for the ultimate Harley oil, and atvs are a whole different animal. but for those of you that do run synthetics in yours and run it longer, just make sure to change the filter, even if you don't change the oil. (side note. i work in a locomotive diesel shop and railroad locomotive engines cost around $300,000, and can hold over 300 gal of oil, yet the oil NEVER gets changed until something happens that requires draining the oil to fix. even then, sometimes the used oil is saved and put back into it).

another note: if you are switching from fossil oil to synthetic in an older engine, you can expect the gaskets to seep for awhile. what happens is the fossil oil builds up a wax in the gaskets that seals them. then along comes the synthetic and dissolves the wax. now the gaskets seep until the oil soaks the paper and swells it to seal it again. at that point you should be good to go.

there are good points on both sides here and i still need to decide what to use in my Brute eventually. i have read that break-in should be done with fossil oil for a couple of reasons. first, the oil needs to be changed frequently during break-in and it would be a waste to run synthetic for a few hours and dump it. second, synthetics usually have higher amounts of the anti-wear additives that can keep the rings from seating properly. but right now i'm kinda thinking i'll run fossil oil and change often, and use the K&N oil filter. (cross-over from harley research: K&N OIL filters are best available. best micron size, crud capacity, higher bypass pressure strongest can, ect..). their air filters arn't necessarily the best, unless you just want high flow.

ok, i've used enough bandwidth on this one, and there is tons of info out there on this subject. the bottom line is most of us have already decided what to use and probably won't change because of this post, but this is a complicated topic and a lot of us could use some plain english answers we can trust. the only real test i have seen was done on Harley oils (again, doesn't really apply here) by American Iron magazine. they sent samples of all the different oils (fossil and syn) to an independant lab for analasys. the Mobil 1 came back with the highest marks in almost every catagory. it was an expensive test to run, so i doubt that we can expect such a test for atv oils anytime soon.

monty

 

Hey what about AIr Filters?? K&N, No Toil? Stock? Uni???

 

i have heard the foam filters like the Uni will hold up better in the brute, where it may get wet because of the airbox issue. the K&N filters are known for high flow, but they do not trap as much dirt as some others (come on, i have read that they do not need serviced until 100,000 miles on the highway. if they were picking up all of the dirt, they would need serviced a lot more often than that. and some vehicle manufacturers will void the warranty if using a K&N air filter. others are ok)
so i'll probably get a Uni, but i haven't finished looking for info on this subject either.

my two cents. your mileage may vary

monty