How much oil should I put in my 1990 loyale with 314 thousand miles? I have never changed it

Not sure.

 

Fill 'er up while checking the dipstick periodically.

 

Once it hits the full mark, run the engine for a few minutes then re-check - make sure it's still at "Full"

 

Voila.

4.20 quarts

Not sure.

 

Fill 'er up while checking the dipstick periodically.

 

Once it hits the full mark, run the engine for a few minutes then re-check - make sure it's still at "Full"

 

Voila.

If you're not sure, please research and then post your findings!