[sdbob]

I've been using conventional Pennzoil 10x40 in my SD s,street car and race car forever. Is Pennzoil conventional oil still quality oil? I use NAPA Gold oil filters the taller model. thanks.

[78w72]

Simple answer... yes.

[JSchmitz]

I've never like Pennzoil. I used it when I first started driving. Oil pressure would drop a lot when hot. Switched to Valvoline and was much better. That was 40 years ago though. lol Not sure about today.

[OG68]

Originally Posted by JSchmitz

I've never like Pennzoil. I used it when I first started driving. Oil pressure would drop a lot when hot. Switched to Valvoline and was much better. That was 40 years ago though. lol Not sure about today.

Same thing I experienced. I had a 71 Comet with the 200 six. Used Pennzoil on the dealers recommendation at every 3000 mile oil change. About 80,000 miles and six years later the oil pressure started dropping. Pulled the engine for rebuild and discovered all my main and rod bearings were down to the copper. Switched to Valvoline and have never used Pennzoil since.
Maybe Pennzoil had a lousy formula back in the seventies.

BTW that Comet ended up going over 250,000 miles on its rebuilt engine. Would have gone further if the oil filter was tighten after an oil change.

[JB Eng Wis]

If a 10W-40 conventional is what you would like to stick too.
Valvoline 10w40 Daily Protection is a bit thicker at 212 degrees then Castrol GTX 10w40 conv, however the GTX does have a bit more anti wear additives.
Both are good conv oils..... Just keep the oil clean !!!

[Tim Corcoran]

Everyone has their favorite oil mine is Brad Penn, now Penn Grade. Not sure why they changed the name