Originally Posted by oldbogie
I have never put that stuff into an engine that it didn't show a loss of oil pressure, primarily at low RPMs where I've always felt that GM engines were marginal to start with.
As I have said in previous posts, my engine has a Melling High Output oil pump.It sits there idling and the gauge reads 55 psi. I call that high enough.
The engine is in a van, not a dump truck or wrecker.
Most of the driving is at 75 mph out on the highway, so while that is not a lot of rpm, it is enough to get me a ticket if I'm not careful.
I have used 5-30 since the day it came out. As I said in an earlier post my driving time is 43 years with 4 different Chevrolets covering 747,000 miles.
I use either Valvoline or Pennzoil and a Fram filter and nothing will change my mind on that........pg