well if it is a stright drive/stick it is best 2 use it on the highway-so u wont b bogged down in high gear

but if it is an automatic you should always use overdrive
you c an automatic has a govener like decice so if you are in drive after a certion speed/rpm it will drop into od but when u leave it in overdrive AT ALL TIME you will c better gas milage

overdrive is not ment to be used in city driving,it can burn the OD bands and clutches -excessive heat.other wise run your OD on insterate or open roads.

this guy dont know what he is talking about. its an AUTOMATIC the only way you can shorten the life is think its a manual and keep dropping it in gear from neutral etc.. overdrive is when the torque converter locks giving you a 1:1 (not including final drive). Its ment to do that to save fuel economy. The button is there so that in certain conditions where you dont want that 1:1 ratio like if you are carring a lot of weight and you dont want it to automaticly shift into overdrive... think of it as a 5th gear.


Over drive is not a GEAR in the tranny its the just the torque converter locking up 1:1 get your facts strait befor you give advice, its really annoying. And im for shure he is not refuring to a manual cause only idiots thinks there are bands in manuals. Befor you start bashing on me keep in mind im a tech for bmw.

HAVE A NICE DAY :)