What fuel should I run in my 340?

91 should be fine as long as you don't have detonation.


As mentioned in your other thread. Check all the normal stuff.

•Plugs
•Wires
•Cap
•Rotor
•Timing
•Carb Tuning
•Vacuum Leaks


But even if all that is good some cars will still not be happy with the winter blends (that has been my experience anyway).