quote:Agree. I'm a dino oil user but would not try 7500 miles or anywhere close to that, even if it was mostly easy highway driving. Do folks think that SL dino oils actually can go 7500 miles or so given fairly easy operating conditions? All of this begs the question of why manufacturers specify such a long interval and why they do not get more specific in defining 'normal' vs. 'severe' service. Do they simply want people to use worn-out oil for too long, so engine problems develop and owners are enticed to consider a new replacement vehicle sooner than they would if no engine problems occurred?
Originally posted by Patman: I'd be downright frightened to see a 5w30 conventional oil's UOA after 7500 miles. Most of the ones we see here after 3k look kinda scary. Maybe 7500 miles if in 60-80F weather, highway only, but certainly not stop and go, short trips and cold weather. Yikes. (of course, that's why the 7.5k interval is listed as normal, and 3k is severe service)
quote:True, there are some M1 reports I've seen on old TriSyn where 5w30 thinned to 20wt in 2k. But generally speaking, the scariest reports we see on here are dino 5w30s, at least in terms of thinning.
Originally posted by GROUCHO MARX: Patman, There are scary analyses using M1 at 1.5k. Driving habits seem to more influential in results than oil brand/type.