Auto-Rx Rinse Phase Oil That Meets GM 4718M Spec

[Craig]

Ok Guru's,
I have a '93 Corvette LT1 that I'm currently Auto-Rxing.
As we must use a non synthetic for the rinse phase
what oil would you recommend?

I believe the GM 4718M spec is the spec for my car.

Thanks,
Craig

 

[dbdeland]

Craig,

Any oil is ok if GM 4718M spec is non synthetic thats great use it good luck

Daryl

 

[terminaldegree]

Craig,

AFAIK, only certain "full" synthetic oils are certified to be 4718M-- no conventional oil is.

As I understand it, the spec's existence came into being because of oil cooling issues [or lack of an oil cooler on the LT1]. I SERIOUSLY doubt that going only 1,500 miles on the clean and 2,000 on the rinse oil would break down a good dino oil enough to cause a problem. The AutoRX is supposed to be taking care of that problem anyhow...

If it were mine, I'd run a good dino oil for the 2,000 miles and change it out on time.

 

[peterr]

Craig

If you feel the need to run an oil meeting that GM spec that is non synthetic for Auto-RX rinse purposes and are willing to pay synthetic prices, there are 4 grades of Castrol Syntec that meet GM 4718M

http://www.castrol.com/liveassets/b...local_assets/downloads/p,q/pds_syntec_usa.pdf

Lots of people complain about Castrol claiming Syntec as a full synthetic. I don't take the personal offense that some do, although I think it fair to say that it may be a little overpriced for a Group III oil. In this situation the miosrepresentation is to your benefit.

Anyhow it will not have the polar issues that a "real" synthetic will, and it is a quality oil that meets your spec.

I asked Frank if Syntec would be considered a Dino oil for Auto-RX rinse purposes previously.

 

[Craig]

Thanks guys, I'll go with the Castrol syntec 5W-30
Craig