You'd have to read thread "av gas", still active, in order to tie in with this one. If my gas gauge is reading correctly, I had approx. half a tank of 93 oct. premium in my tank. I pumped $10 of Sunoco GT 100 ($3.91/gal)which was roughly 2 1/2 gallons. It was white and smelled different. I'm confused and the kid at the cashier didn't know, but the pump is marked "leaded" and Sunoco markets this product as street-legal, unleaded gas. Anyway, there's no real appreciable difference in performance (positive or negative), except maybe it's popping a little more on decceleration. But the real plus is there's no more bubbling gas in my see-thru fuel filter, I guess attributed to a cooler-burning gas.
Hope this helps anyone wondering if they should try this fuel. Perhaps a greater concentration would provide more performance enhancement, perhaps it runs worse. Maybe I'll try av gas next time, it's cheaper.

JR

|UPDATED|8/1/2004 7:27:59 AM (AZT)|/UPDATED|

You're right. It could get worse or better. So many variables for any given vehicle.

The reason it pops in the exhaust is easy to explain. The highter octane burns slower, and your burn was not complete. Some fuel was left over and traveled to the exhuast system. The slower burn of the higher octane caused a bit more to travel to the exhaust unburned. Once in the exhaust the heat and mixing with air, causes it to light, and pop (small explosion).

This happens on decell, and it's fairly normal for a carburator car, and nothing to worry about. It is not an indicator of what is happening for combustion when cruising or acelleration.

Intersting stuff, isn't it?

|UPDATED|8/2/2004 10:04:36 AM (AZT)|/UPDATED|

kstyer said: Intersting stuff, isn't it?

The theory of internal combustion...fascinating stuff. So many different forces working in there.

JR