I had a old honda 3 wheeler and I always used 30wt. car engine oil in it.(bike is 21 years old and still runs good.) I have a newer 4 wheeler 1998 honda 300 but always used honda oil in it.I do a lot of work with the bike which makes it run hot. I am thinking of using Mobil 1 15/50 syn. car oil. Any body tried Mobil 1 syn car oil in their ATV?

I used to ride a Suzuki V-Twin and I ran The Mobil 1 Synthetic in it.  I had problems with clutch slippage (wet sump) in it when using the Suzuki oil. Mobil 1 cured all the problems.

Of course this will void the warranties if you get caught doing it.

I have a new honda 360 4 wheeler. Have only used Honda Oil in it though

Your 4 wheeler engine and transmission share the same oil. That's why the owner's manual specifies their own brand of oil that doesn't have friction modifiers added. If you want to use synthetic oil, make sure it is Mobil's MX4T. It is what's recommended for all motorcyles with wet clutches because it lacks the friction modifiers. Switching to synthetic is the best thing you can do to an air/oil cooled motorcycle engine because it lets the engine run cooler (less friction) and the synthetic oil doesn't begin breaking down if you overheat the engine.    

For scooters or atv's the only oil to run in them is [b]BelRay[/b], the [b]EXL[/b] is an oil based oil best for big V-Twins and the [b]EXP[/b] is a synthetic and probably best for your atv or Gold Wings and crotch rockets.

This is only oil I run, and while it is expensive it's important to note (as mentioned above) that scooters and atv's have far different requirements than automobiles.

I learn of this oil back when I used to run nuthin by Castrol. My motorcycle mechanic of almost 20 years showed me an article he had written for the "Dealer News" in which he described the oil needs of scooter engines and why Castrol and several other auto oils should never be used in scoots. He was summarily "sued" by Castrol who objected to his naming their product, and article was revised, describing the oils in detail but omitting the names.

My mechanic is also a great friend and while his shop is now closed due to his fight w/ cancer, in his day he was, and still is considered one of the finest scooter mechanics in the USA. He trained some who went on to prominence, Vance of Vance and Hines and many of the local repair shop managers worked for him and were trained in his little shop here in Houston. He also at one time was the holder of 50-60 1/4 mile speed records, some of which have never been broken. He is known by his friends simply as "Uncle Paul" and when he tells sumthin 'bout scoots ya can take it to the bank.

[b]Bel-Ray[/b] is hands down the finest scoot/atv oil on the market, it ain't cheap (4-5 bucks a quart) but it's the only oil that you can put in your scoot and 2 days later you'll swear your scoot runs better, smoother and quieter. I have turned all my friends who ride on to it and everyone of them agrees, made a noticable difference in the way their scoot runs and shifts, if ya try it, ya won't ever go back to any other oil.

Mike