Right now I'm using Castrol Act>Evo SAE 10W-40 premium motorcycle oil. The label claims it exceeds API SG, JASO MA specifications, and claims to have "Synthetic Active Protection Molecules" ... whatever, I presume it's a blend, and it's about $5 per quart with shipping.

As I said in another thread about oil, I think as long as the oil you're putting in your ATV meets the API SG & JASO MA specifications, and you're changing oil every 30 hours or about every 1000 miles, you won't live long enough to see your engine fail due to an oil deficiency.

 

I have used Amsoil exclusively for several years. Mytwo bikes and my new Kawi 750i are lubricated with Amsoil 10-40. May switch the ATV over to 0-40 the next time I change oil. Great stuff, well worth the price.

 

I did a post a couple years ago asking who switched to a winter weight oil for the cold season. You would be surprised at how few people who ride in very cold climates ever thought of running a more pumpable oil in cold weather. In reality, most folks don't change their oil even once a year, much less change it for the seasons!

In most of the country, 10W40 is a good 3-season oil, and 5W30 or 0W30 is a good winter oil.

 

We went on a ride last month, and had more people than I had quads. So, I called my brother in law and borrowed his. (it's financed in my name, he makes the payments)

Anyway, I told him I lube it and change the oil. Figure it's the least I could do since he let us use it.

Turns out, it still has the factory oil filter on it. [img]i/expressions/face-icon-small-shocked.gif[/img] And it's a 2004 model. [img]i/expressions/face-icon-small-shocked.gif[/img][img]i/expressions/face-icon-small-shocked.gif[/img]

Even though he only has about 20 hours on it, I couldn't believe he didn't change it yet. Even if mine have just sat for 3 months (it's sucks but it's happened) I still will change the oil before I take them out again.

 

A advantage of full synthetic over conventional oil. is also flow rate in different temp ranges. Even if the two oils are say,..10w-40 the Synthetic oil will still flow better in cold temps and handle a higher heat in hot temps over a petroleum oil of the same weight.