Originally Posted by Broncoman13
This is true which is why I don't buy into the 25k thing with AMSoil. The oil may maintains is lubrication, but the "dirt" that mixes into the oil over time still causes friction. I'm comfortable pushing it to 7500 miles. Recommended interval on my 35 is 5900 miles.
Well, I see Amsoil has "severe duty" intervals that are half the miles of "normal duty". I see this 0w-30 (which I think I'll start using) has 35k/17.5k intervals. If I put a whole lot of miles on my vehicles I wouldn't go 35k, but I only put about 8-10k on the vehicles each year, so I just stick to the 1-yr interval.