Engine oil

[Richard P.]

What's the best oil for my original 1965 327/365 Coupe, 75,000 miles?
I know you guys have talked about this but apparently I don't know how to use the archives.

[Duke W.]

15W-40 API Service category CI-4 *NM*

[Duke W.]

Type "CI-4" into search box *NM*

[Gerard F.]

Is this the right oil, Duke

$8.79 a gallon at Kragens

Jerry Fuccillo
#42179

[Duke W.]

Re: Is this the right oil, Duke

That's what I use - 15W-40 Chevron Delo 400. Note that the API service category is "CI-4 Plus". The "Plus" is a slight upgrade to CI-4 and most HD diesel engine oils now include the "Plus" in the API service category designation.

It's all about the API service category. If it's CI-4 or CI-4 Plus it's the right stuff regardless of brand name to include Mobil Delvac, Shell Rotella, et al., or a house brand name you trust.

If you insist on a synthetic base, which IMO is of no value in a vintage car that sees low mileage accumulation, is only cold started at mild temperatures, and gets an annual oil change, the major national brands as mentioned above offer 5W-40 synthetic-based CI-4s that are, of course more expensive.

The conventional mineral oil based CI-4s like 15W-40 actually have a little synthetic stock blended in because it's necessary to meet the tough CI-4 oxidation certification tests, and the 15W viscosity rating means it's okay for cold starts down to about 10F. If you like to start up your vintage Corvette in sub-zero weather then you should use a synthetic CI-4 for the 5W cold viscosity rating, which is okay for cold starts down to about -20F.

If you want to learn more google on "Delo", which will get you to the Chevron/Texaco web site where you can find all the tech specs and MSDS sheets.

Thanks for posting the photo! ... picture worth a thousand words.

Duke

[Richard P.]

Re: Is this the right oil, Duke

Thanks Duke and Gerard.