The 25,000 Mile OIL

[Cujet]

Originally Posted by John_Conrad
not on topic much, but back in 60's 70's i went 10k oil service with Havoline


Oh, you were not alone. Plenty of people did exactly that. Sludged up engines with worn timing chains were the result.

 

[MolaKule]

Originally Posted by MolaKule
This one surprised me as well.

...Later, in 1969, Pontiac would recommend 12 month or 12,000 mile oil changes.

In the period from 1970 to 1990 recommended oil changes varied between 5,000 miles and 7,500 miles. The 7.500 mile oil OC interval would be found in the 1975 Oldsmobile and the 1977 Chevelle manuals.



This information came from the S.T.L.E. and those oil changes mentioned above were for specific models of those stated years but the specific models were not identified.

The service manuals or Operator's Manuals for a specific model in a stated year may vary as to recommended oil changes.