Fed messing with oil formulation

Yes, this has been an issue for some time. It is of particuar concern for flat tappet cams and lifters. If you want to read even more go to www.hipomustang.com and search the message board. There's alot of info. there along with some recomendations.

There are plenty of posts right here on the PI Forums about this subject. Without getting into a long dissertation, what our older motors need are motor oils with an API SJ rating. Diesel motor oils such as Shell Rotella and Chevron Delos 400 had these ratings until just recently. The hot tip now, as one of the linked web sites points out, is racing oil, oil specified for off highway use only. I've never been a fan of Valvoline, but Valvoline VR1 racing oil is my new off the shelf choice.

I always like to mention that single weight motor oils are manufactured with a higher quality base stock, with a more sheer resistant molecule. Therefore Valvoline VR1 30 weight gets my vote.

cowboy from hell