Gas for 1965 Buick Skylark

have a 1965 Buick Skylark - what is the best gas to use 87, 89, or 91 all are full gas no ethonal. Do I need to add a lead additive and if so how often?

Cheers -

 

Are you in New Zealand? (I see "kiwi" in your name)

The RON numbers of NZ petrol are different from the fuel in North America.

 

I run 91 octane non-alcohol in my 65 Special 300 2 barrel with no problem.

 

Same here, 91 octane ethanol free gas.

 

if its a two barrel the 91 should be fine for a 4barrel wild cat you will need 93 most likely mine requires it/

 

The thread starter never returned to the board after posting this on October 2nd 2023.