I've used Mobil 1 10w-30 in my truck for 17 years. This weekend I went with Pennzoil 10w-30 HM, and a NAPA Gold filter. Since I'm only putting around 2K miles a year on it now, I figured synthetic was no longer necessary. Not sure if I'm gonna stick with the PZ, but thought I'd give it a try. Not sure if I needed HM either, as the truck doesn't leak any oil or have any other problems.