Bought Valvoline VR1 20-50
 

I bought Valvoline VR1 20-50, apparently I wasn't paying attention. My 1990 ZR-1 #2822 has 88k miles right now and is running great. My question is, am I safe with this weight oil? I live on the SE coast of NC and it's hot down here. If anyone has an opinion on this weight oil in the LT5 please chime in. I have been running VR1 10-30 Dino oil with no issues and a Bosh 3401 filter. I can save this 50 weight for my 1972 455HO Pontiac if need be. Thanks guys, lovin my Z, over 10k miles since May of 2020.

Re: Bought Valvoline VR1 20-50
 

I'd be savin that for the Pontiac.

Re: Bought Valvoline VR1 20-50
 

I had a 1954 Aston Martin DB 2/4 that smoked a bit so I ran 50 weight in it and that minimized the smoke. But I would not run 50 wt. in an LT5. Too close to molasses. As efnfast noted, save it for the Pontiac.--Bob

Re: Bought Valvoline VR1 20-50
 

Thanks for chiming in guys. Next time I will pay closer attention to the weight. Thanks again.

Re: Bought Valvoline VR1 20-50
 

My understanding is that our LT5 needs a zinc-phosphate additive (ZDDP) to protect camshafts... similar/same as other engines of same era. I recall Ford and GM having issues with camshafts and lifters in the mid-70s up into the 90s, so engine oils were developed accordingly. Some additives hamper increasingly stricter emissions limits, so as oil technology progressed, zinc was reduced in more modern oils. Newer oils are not necessarily backward compatible. Fortunately, there are still zinc additives and oils with higher zinc content available for those special needs.