better MPG?

[rfix'n]

Replaced my tranny ground strap and after two tanks I am getting an extra mpg. Not noticable performance wise, Coincidence? No other changes have been done.

[Rot 911]

I suggest buying a cool collar to place around your new ground strap!

[widebody911]

Maybe the guage itself works better now?

[grant lyon]

if the car's never warmed up ... .

[stlrj]

It is quite possible that your mpgs may not be accurate since the 911 gas tank is not properly vented under the spare. There's a 2 gal bubble there that may or may not fill with gas at every fill up.

Try filling your tank when almost empty, drive around a few miles, go back and fill it again, you'll never understand why it takes an extra 2 gals of gas.

The answer is, when you started driving after the first fill up, the void under the spare started filling with fuel everytime you went around a corner, accelerated or braked hard causing 2 gals of air to move from under the spare to the main chamber of the gas tank.

One way to avoid this is to take your mpg readings with no less than 1/2 a tank of gas to avoid an air pocket from forming under the spare and making your calculations very inaccurate.

Cheers,

Joe

[HawgRyder]

I'm lucky to have a gas station nearby that has quite a tilt on one of the pumpms.
If I fill at that pump...with the gas fill on the high side..I can put in several more liters.
Bob

[304065]

It is entirely possible that you are getting better combustion now that you have a good ground. I once disconnected the ground strap between CDI box and engine and the car ran on three cylinders. Connected it back up and it purred. So depending on how lousy the ground was initially it's possible that you are getting a better spark. A long shot, and you probably would have noticed if it had been THAT bad before, but not beyond the realm of possibility.