[dhgeyer]

Well, yes and no. Synthetic oil will last a lot longer in terms of breaking down and losing its basic ability to lubricate. So that part is true. I've never heard double the change interval. What I've usually heard or read is 5000 miles if the usual oil change interval is 3000.

The other side of the issue is that acidic products of combustion build up in engine oil. Also, products of engine wear that are fine enough to get through the filter are still in the oil. This is no less true of synthetic oil than it is of petro oil.

So, some of us change the oil at the shorter interval regardless of the oil used. If I run synthetic, or a semi-synthetic blend I'll do it for other reasons.

For my money, frequent oil and filter changes are the single best and easiest thing you can do to keep your engine smiling for as long as possible.

Oh boy! An oil thread. Everyone will have an opinion on this one. Play nice now.