Allen4rmGromLak
OBS Enthusiast
I have been using the cheapest 10w30 and 10w40 I can find for the past 300k miles. Engine has 540k. Desperately needs to be pulled and rebuilt. But I'm running about 20 psi at warm idle and about 40-45 psi at freeway speeds. My factory guage reads higher, so I go off my aftermarket guage