The big Automakers created a Top Tier Gas standard in 2004. In my area that includes Shell and BP. Marathon may have enough STP additives but do not have the cert. Otherwise the Chevron Techtrolean Fuel additive is the real Mccoy. It will not only keep the engine clean but it will also clean the exh. So the greatest thing about TOP Tier gas is the cleaning, maybe prevents 10% Ethon. Damage?
16 Magnum Midwest USA
Last edited by Bueller; 05-12-2018 at 08:24 AM.