over drive off or on?

[98LSC32V]

How do you drive within the city, overdrive on or off? I have always driven with overdrive off until I hit 55-60mph but someone was telling me this builds up more heat in the transmission and is actually worse for it?

 

[04SSHD]

I just leave it on all the time, I heard that it is better to drive with it off in the city but I never do.

 

[torquemonkey]

I drive in the city, hills, mountains w/ it off. An aisde to that, the higher RPMS keep my A/C compressor spinning faster (Cooler air comming out of the ducts) and keeps the car closer to or in the "power band". The heat issue I cannot speak w/ any real profesionalism other than my personal experince in that the higher RPMS keep the water pump spinning faster (circulating more coolant) and you are not "lugging" the power train w/ a higher load than output. Meaning your car performs best at a higher RPM. I have noticed that my instant gas mileage is around 21-23 driving in third gear @35-40 mph, w/ my A/C on and in OD I get 12-16.
From my experience, this tells me the engine is performing at a better under the same "load" at a higher RPM. <that or my computers hosed>

 

[formerknown]

I have always driven with overdrive off until I hit 55-60mph but someone was telling me this builds up more heat in the transmission and is actually worse for it?

You know what else builds heat? Constant stoplight-to-stoplight upshifts and downshifts from OD, and "gear-searching". Leave it off until you reach 50-55. Maybe it's just me, but I notice better gas mileage by leaving OD off until 55. I'm easier on the gas with OD off.

 

[JMiles_T]

I leave it off at speeds below 45.

 

[seanklsc]

When I had my Mark VII with AOD, I would leave it out of overdrive for my city driving. With the 4R70W I just leave it on, no harm done.

 

[rmac694203]

I always turn it off when driving under 60, but that's because my transmission is screwed up and it shifts better with overdrive off at low speeds.

 

[MediumD]

I leave it on all the time, unless I'm going up a fairly steep grade. I never see any gear hunting (unless I'm constantly on & off the gas.) I have experimented alot with what instant MPG I'm getting in 3rd or 4th, and it's fairly even at around 40mph, higher than that and 4th gets better mileage, lower than that and it rarely goes into 4th in the first place.

 

[JC1994]

I dont turn mine on till 45-50 mph.

 

[shiryu0]

off in the city, till 50mph+ when im getting in the highway, then turn it on.......on mine if im cruising at 35mph in 3rd it gives me 28-30mpg.......40mph in 4th w/cruise on is like 30-35mpg.....itll shift into OD at around 37, so just i just bring it up to 40mph and hit cruise in town, were i can go 40mph......

 

[turborich]

I have been told that driving your car at city speeds in overdrive really wears out the trans, A couple of transmission shops told me this. I am really not sure though. The ford manual says to leave it in overdrive unless climbing a steep hill. I normally try to leave it off in the city though.

 

[Dominus]

Keep in mind that there are many cars out there that do not have an overdrive button and they do just fine with much weaker engines.

I have found the transmission more than adeuqate to decide gears and have never encountered any gear hunting.