Pennzoil 20W-50 Motor Oil
Product Review (submitted on July 16, 2012):
I have used this oil in my 1976 Chev 4X4 since around 50,000 miles. Used 10W-40 for first 50,000. Never have had a problem. Much of my driving is highway is several hours at a time on the freeway. I feel it gives better protection on these long runs. Now have 97000 miles and the truck runs and sounds great.