If you can't hold your foot steady at a certain speed then set your cruise at 35 or 40 mph. It also should be in the same section of road that is flat as possible to give you a accurate reading. Mill500 I agree with you about the rpm's being higher with the O.D. off but at below 40mph. it does'nt seem to be reving any higher. Try the test and let me know what you come up with? Thanks.

 

05ramlaramie,

Does anybody make a switch to turn the Overdrive off. This truck is the most anoying when shifting into OD at 40mph. I usually don't use OD unless I'm on the highway, otherwise this tranny continues to shift. I tried the tow/haul but all that does is hold the shift pattern a little longer.

 

I get good mileage for a Hemi with the OD off. But Last Saturday I really solved my gas mileage problem once and for all. I parked my 04 Quad cab Hemi in the Drive way and I went out and bought a 06

Pt Cruiser Convertible 4 speed automatic. 2.4 engine. The first tank and I got 22 miles per gallon. Not bad. So now I have two PT cruisers ,a Buick Century and a gas hog Hemi. not bad for a guy who is retired. I'll start using the Hemi again when the water gets above 70 degrees so I can pull my boat again.

 

If you want to try to do an experiment to see if driving with OD on/off affects MPG
try using up a tank of gasoline with the OD off,
then on the next tank of gasoline keep the OD on.

I found that you will need to run this experiment
over AT LEAST 8 tanks of gasoline
to get rid of enough natural 'scatter' to see a reliable result.

Of course it is best to keep filling up with exactly the same gasoline
and keep the tire air pressure checked more frequently to keep that the same too.

For 2nd gen Rams,
see this post

http://makeashorterlink.com/?T26D43F8C

which has the results I got deep in the replies
but that forum might require registration

 

I often shift out of OD into tow/haul mod when I'm aroud town (95% of my driving) as I get tired of the tranny not being locked, i.e. making more heat. What I've noticed is that it is nicer to hold 1 gear and be able to push on the gas without the RPM's shooting up every time. As far as MPG increase/decrease; I haven't seen it one way or another.

 

I leave it in 2nd for around town driving when I know that 35-40 is all I will be getting. Keeps it from constantly shifting. It is better for gas mileage but though not very much. Gas mileage is why I still have an 03 Nissan and a motorcycle.

 

Some of you guys need to learn something about these transmissions.

The Tow/Haul switch lights the T/H lamp and prevents the trans from shifting from 3rd into 4th and beyond. Not only 5th.

The other thing you feel when in 3rd and with the T/H mode on is the converter lock up, NOT 4th gear.

With T/H on, the coverter will lock up in 3rd. With T/H OFF, it won't lock until 4th. And it doesn't just lock up, it has clutches that ease it into lockup.

Ever feel the rpm drop slowly when in 4th?

 

Maybe your truck works that way, but in mine tow/haul only disables 5th and changes shift points. I wish it would also disable 4th.
When you push the button it does initially shift into third gear, but then it will shift into 4th.

 

The only thing I would change on my ram would be that anoying sleep mode it goes into when I'm driving about 40 around town, sometimes I put in second and leave it there because I can't stand it. Is there a shift kit that would work?

 

Can you post proof of that? I'm with 99% of the others that all T/H does is disable 5th and change shift points. It would be great if it works the way you say......