[mpanten]

some of them have different additives and cleaners and this will vary by state beacuse each state has their formulation requirements so it is possible one brand will run better in your particular car, especially in a car like a cobra. I know two people with late model chevy trucks who swear BP high octane has fouled their injectors and that it was caused by running high octane when the manfacturer reccommended 87.

Some have a higher ethanol content than others. BP used to have a higher sulfer content but they have droped it. I agree with you that there are some differences but none of the good major brands is going to hurt you. I usually use Sunoco, BP or Shell beacuse they are close. Im no expert but I have a lot of clients who are and they tell me that they are all good and about the same, at least for a late model car. Incidently If you use an octane booster the only one that actually works is Lucas.