New transmission...better MPG?

Question

Will a new transmission help gas mileage? the old one overheated and the bands needed adjusting...The new one is the same kind of transmission, but rebuilt. It seems like it would get better mpg now. Before i was getting 19-21. Its a 1989 Thunderbird, and should get 19 in town and 27 on the interstate.

Answer 1

I guess you talking about automatic trans..lol Yes if the 'bands' were slipping the power from your motor was not getting efficiently to the wheels. A new tranny ( same as the original one) would fix this. If you want to improve gas mileage, power ect. you need to change the differential gears to match your driving. ie. High ratio for driving on level ground and low for mountain driving. All vehicles come with a middle ground to accomodate both. If you want to 'tweak' it the best way to do it is changing your differential ratio.

Answer 2

First of all, the bands in your transmission are not adjustable manually, as they were in some older transmissions. As far as fuel mileage, it may increase, as you might have been loosing power due and running at increased RPM's due to slippage in the clutch disks or other concerns in your old transmision. If your fuel mileage was 19-21 before the transmission overheated and started slipping, likely you will not see much if any gain in fuel mileage. Your culprit for guzzling gas likely lays elsewhere, perhaps something simple as requiring a tune up or an improperly operation sensor (O2 or air sensor).

Answer 3

Ok. Your transmission does have adjustable bands and they have nothing to do with slipping or mileage. They just affect shifting. If you were only getting 21 on the highway, service and adjusting aren't going to help. A rebuilt might help, or the transmission might not be the problem. You can't just keep throwing money at it until you get lucky. Someone needs to figure out what's wrong.