I had a 1993 S-10 with the 2.8 V6 And after changing the factory oil I ran M1 15-50 for 140,000 miles. Never had a problem or a leak and when I sold it the new owner did a compression check and it was at factory specs. Also did this on a 1992 4.0 V6 Ford explorer with no problem. My 2006 GMC Canyon I5 used M1 10-30 and I changed the oil at 15,000 with a filter change every 5,000. Never once had the oil change light come on during 12,000 mi. it went 160,000 with no oil related trouble. I won't do this now but after warranty I will probably use 10-30 M1 as it is hot here in Fla. I think whatever you use it will be good as long as you change it on time and keep up after other engine maintenance.