xRYD3Rx

I disconnected the battery on my 3gs and when i connected it back everything was working fine even the clock was showing incorrectly but after a few minutes of waiting it changed by itself showing the correct time. But the MPG was 19.7 before disconnecting the battery it dropped down to 7.5 then slowly came up to 20.3 then went down to 19.6, 19.5, 19.4, and now its currently at 18.4.

Its pretty much going up and down. Is there a way to fix this or will it get fixed on its own?
Driving the same way as always no driving change.

JSM1284

The average MPG is since last fill-up. It will constantly change to reflect the average

xRYD3Rx

So you think it will go back to normal after my next fill up?

anthrax144

You can be concerned if it's not back to normal after 2 or 3 THOUSAND miles. You're looking at a very small sample to compare it to. If you want better gas mileage right away, slow down.

xRYD3Rx

Its currently around the 21.5mpg now has not changed much

JSM1284

The more miles it gets on the tank, the less it will change, since the average is equalling itself out.