Hey guys so just wanted some input on this. I typically use two gas stations to fill up my car. Both are Shell and I use V-Power 93 Octane exclusively. Gas stations A & B. Station B is normally the cheaper of the two so if I'm around there ill fill up there but if not i use station A. now to the reason for the post....

Station A when i fill up i notice my exhaust tips stay cleaner for longer.

Station B the tips get really dirty much faster.

Running a Joe Z Catback and have been able to replicate these results multiple times. What does this mean? either station B has better gas and the detergents are cleaning my injectors better OR the gas is no good and causing extra carbon? (forgive me if i sound ignorant with that statement)

Just curious but i don't know if its a good or bad thing, hopefully someone can enlighten me here. thanks

 

Regardless cheap brands or expensive, I do not mind paying the extra $1.50ish to fill up (base off of 10 cents higher per gallon). I would trust Chevron and Shell over Costco and whatever else. Saves myself from using that $1.50 on hot cheetos

 

my neighbor is a tanker driver, as he has explained it to me he delivers to Arco BP, Circle K, 7-Eleven, Shell, 76, Costco, Chevron, and Valero.
during a normal shift he will deliver to several different brands with the same tank, the only difference is what additives he adds to the stations underground tanks at the delivery.

sounds to me like the two stations you are talking about get their deliveries from different third party tankers which likely fill from different refineries. so yeah one has better gas than another. I've never noticed a issue with the exhaust tips, but I can tell you that of the 4-5 different Chevron stations I used between my house and my office, I get 2-3 better or worse mpg depending on which one I fill out. Funny enough the one that costs the most usually yields the lower mpg.

 

As far as I know the dirt on the exhaust is known as black soot. This is a result of incomplete combustion of fuel in your engine. I would refuel from the gas station which leave the exhaust cleaner, since it is more suitable for your car.