NJ-USA-Costco Gas 2extra MPG?

[AB M2C]

Shell V-Power is the only kind of gas to get. Best/ most detergents. The reason you're getting better mileage is almost definitely because, get this you're driving easier, crazy I know. A chemistry related cause could be the gas is slightly lower octane, thus will more readily blow up. Lower octane gas in turn yields a more powerful explosion and better gas mileage. This however is rather unlikely. The octane percentage would have to be decreased quite substantially which a company would not want to do, as advertising 91 octane and giving out 89 octane could lead to detonation, leaving the gas station/ company liable.

[shah269]

Lower octane gas in turn yields a more powerful explosion and better gas mileage...and now the fan boys go nuts!

[BEAR-AvHistory]

Originally Posted by shah269

August and september both months 100% costco gas.
I got between 2mpg and 4mpg more out of the car. It was just odd!
I asked other friends and they had about the same bump in mpg.

Last week went to Hess...lost 4mpg in one tank.
My drive to work is all of 10 miles back streats, 40mph in 6th just putsting.

It's kind of strange...makes you wonder.

They might have gone to winter mix, don't know the months Jersey switches over from summer blend. The added E85 will tank fuel millage & its removal ups it.

As for the big explosion thing you are right regular makes a nice big blast. Problem is the ECU does not like big blasts so it cuts ignition timing killing mileage & power. That's why track days get straight 100.