use of synthetic oil in a C3 corvette

[Lou Farrugia]

Could you please advise if it is advisable to replace the existing engine oil with synthetic oil manufactured by CASTROL (Syntec - 10W-30.

I've been told that in older vehicles the synthetic actually improves starting, performance and mileage.

It would be greatly appreciated if you could repsond.

Thanks

[Duke W.]

Re: use of synthetic oil in a C3 corvette

For typical vintage car service - low annual mileage accumulation, and no sub-zero temperature cold starts - you're better off using a mineral oil based CI-4 because of the better additive package and changing it one a year. Lot's of discussion on this subject in the archives.

The primary advantage of synethics is longer service life due to its lower oxidation rate (but the additives deplete just as fast and SM oils have less than CI-4s to start with) and better cold flow in artic climates.

Most of what is written about synthetics is myth and marketing hype.

Duke