posted 09-29-2000 11:43 AM
Mike, that sounds like pinging. It happens to different cars with different gasolines, but the major reason can be blamed on the grade of gasoline.For example, if I put gasoline from a "cheapy mart" type operation (7-11, Beacon, Ultra Mar) in my Crown Vic's engine, then my engine will ping. It doesn't happen if the same gas is put in my 5.0, or my fathers Toyota Avalon. I don't know why it affects my Vic and not my 5.0. But sometimes it even happens to my Vic when I buy gas at a "major mart" like Chevron. But that's very rare.
Whats the main cause? It's the grade of the gasoline being purchased. A chemical engineer type dude who worked for Mobile Oil told me (when I was a teenage "pump jocky" working at a gas station) that during the process of turning crude oil into usable petroleum products, different grades of the product are produced.
For illustration purposes, I'll use the designators A Grade, B Grade, and C Grade.
The A and B Grades, when processed into gas, are of a much higher quality than C Grade. The C grade is normally purchased by the "Mom & Pop" operations, the "cheapy marts" etc. The A and B Grades are usually used almost exclusively by Shell, Chevron, Union 76, etc. If I remember correctly, the "majors" aren't even allowed to buy the C Grade for their stations.
Naturally, because the C Grade is purchased at a cheaper rate than the A & B grades, the price of the gasoline at those places is usually a little lower.
Anyway, it's this different quality (grade) of gas that can effect the performance of a car too.
Not saying you didn't buy the gas at a "major" station...just trying to share stuff with y'all!
Stewart
[This message has been edited by Stewart (edited 09-29-2000).]
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posted 09-29-2000 10:22 AM
