TheRebel

I don't know about Pennzoil synthetic but their regular blend is notorious for build up. I've seen engines when I worked at NAPA ranging from 20,000 to 100,000 miles. On a 1000,000 mile engine, the valvesprings were almost hidden because of all the build up. 20,000 mile engines were also very dirty. Actually some of the engines brought in that had been running Motocraft oil, were some of the cleanest.

cfr865

Penszoil is one of the best if not the best dino oil, the engines your talking about must have been the Chrysler 2.7. Penszoil has one of the best uoa's from Blackstone labs. there is.

nuturf87

i run 10w 30 full synthetic, royal purple.






88 hatch w 331 stroker
tko500
175 shot of dope
9.34 @ 147mph

simpsonfan13

who told you that? that's not true. not if your car was put together correctly and tuned properly.


as far as the OP Q goes:
i personally use Royal Pruple 10-40
although Mobil 1
Castrol Synthec
and Penzoil Platinum are all good

TheRebel

This got me to wondering why I've seen so much sludge in cars running Pennzoil (many were not Chrysler, my chevy 350 had a lot of gunk in it as well because I used to be an avid Pennzoil customer). Basically what I found from googling Pennzoil UOA is that that in tests it is a really good oil but in real life a lot of people have exprienced sludge with it. Pennziol is suppose to have a detergent it it that works a little to well and traps trash in it instead of letting the filter to its job. Sorry this is a little off topic and their synthetic may be awsome. I just wouldn't personally use it because of past problems with their dino oil.