Chevron is a fine fuel for a Cobra. Shell adds plenty of additive too. Circle K does not add as much as the Top Tier level. Go to
www.TopTierGas.com for a list of the retailers that use extra additive. California gasoline is very clean burning leaving few engine deposits, the use of extra additives is not as important as in other parts of the country. The octane is only 91 and that hurts.
It is human nature to convince yourself when you buy the most expensive fuel on the street and your engine misses or hesitates, your engine needs a tune-up. But if you buy the mini-mart bargain gas and your engine misses or hesitates, it's that cheap gas! This is exactly like the same feeling you can get when you change your
oil. Your gut knows an
oil change will not make the engine run better. But it sure seems like an engine does run better sometimes!
The Techron additive does not change the driveability of the fuel instantly. The Techron does eliminate deposits from forming and cleans them off a dirty engine. The dirty valves they show in their ads are not the result of running California mini-mart fuel. I don't know where the dirty valves come from.