thepit56

I bought a 2005 5-speed automatic v6 mustang and it has over drive. when should i turn it on/off and what is it used for

BLK89GT

its a 6 cyl so just leave it on
its for speeds over 45 or 50 cant remember exactly

tbirdscwd

If your driving aroud town, leave the OD off. If you are on the freeway or are cruising somewhere else above 50 then put it on. One of the biggest reasons for auto transmission wear is excessive shifting back and forth between gears.

thepit56

so your saying that if I leave overdrive on when driving around town it will wear down the transmission and decrease performance

ShadowWulf

Your '05 V6 has a 5-speed transmission, the 5R55S.

4th gear is a direct 1:1 ratio, and 5th gear is an overdrive ratio, meaning the output spins faster than the input. (It gives you higher MPH for lower RPM. Suitable for highway driving)

When you press the O/D button and the O/D light comes on you are shutting off the transmission's ability to shift into 5th gear. Effectively turning your 5-speed into a 4-speed without an overdrive gear.

Some people use the O/D shutoff when drag racing at the track, some use it during city driving to avoid shifting into 5th gear.

For general drving, you should leave it off and allow your transmission to shift normally.

tylerl90

Yes

05pnygt

so only use overdrive on highways..

OnyxCobra

I've always just used OD all the time, never had any problems. My theory is that if the car is going too slow to use it then it won't, so it won't be shifting in and out of it in the city anyways.

tbirdscwd

Your car is set up for economy, so if you are cruising, it will shift into the highest gear possible to save gas. If you notice when you are cruising at low rpms and then give it a little gas, the car will usually downshift and as soon as you let off the gas it will shift back up. This excessive shifting leads to worn out autos down the road. If you have the choice between D and OD, then use D in town. How often do you need to be in fifth around town seriously.