I know most gasoline posts here are on the subject of octane rating - 93,
87, (premium, regular), etc.While it's wise to follow the owners manual recommendations on octane, not much has been said about TIER ratings. There was a time (only a couple of years ago) when we were advised, in addition to the octane rating at the pump, that we should only use "Tier 1" gasoline. If a station sold "Tier 1, all octane levels there were Tier 1. The pumps actually bore the "Tier 1" label.
Government requires that all gasoline marketed here contain a minimum detergent level, but Tier 1 contained a more effective amount. (At least this is what I've read, anyway.) I remember checking pumps for the Tier 1 labels in the past.
At the last few fill-ups, I've been unable to find the labels at any brand/station I've used. Now I read that some auto manufacturers (BMW, Maecedes, etc) and oil companies Conoco, Shell, etc,) have agreed upon a new "Top Tier" designation for their better-than-government detergent level gasolines. It seems the Top Tier designation has replaced "Tier 1" designation.
If anyone knows of an off-brand (WaWa, Delta, etc) or brand-name (Hess, ) around here that is Top Tier I'd appreciate hearing about it. Thanks.