Hey fellas.
I know NOT to use overdrive when towing.
I am running 2600 rpm at 60 mph. in drive,,, we wont talk about the terrible mpg.
But wondered :
Is it ok to click into overdrive when going down a hill, At least in order to get a little momentum to crawl the next hill?
And of course drop it back in drive when climbing.
we are towing a small fifth wheel.

Thanks

 

You can accelerate a bit when going down hill, but, I still wouldn't hit O/D. It really won't make that much of a difference in fuel economy anyway..... as accelerating down hill with that heavy load will happen whether you step harder on the gas or not.

 

Like Hey You said, stay out of OD while towing on a stock tranny.

I tow my Drag Dakota behind my 98 2500 Ram, I wanted to put in 4.10s, but the installer told me not to....With a 3.55 rear end, I'm around 2400K at 60 mph. It's perfect. If I want to get off the line quicker, I'll just unload the Dak.

 

I pull a 30ft,6500LB dry weight and I get around 8-10 pulling. I never use OD. I dont think useing OD on a down hill run will help MPG. What kind of milage do you get?

 

11.5 usually, pulling look like 8.5
I just thought on say a 2 mile down hill run .. shifting into over drive would let everything rest for a couple miles. bring rpms down, and allow me to let off the gas peddle,.
Just lettin off the gas in drive it brings my speed down on a down hill incline.
as if I had down shifted.

 

That's exactly the way it is supposed to work, until speed drops enough that TCC disengages. (like pushing in the clutch on a manual trans.)

The PCM will only add sufficient gas for the current load on the motor. If you are going down hill, even in third, letting off the gas will result in engine braking... and you will slow down. (depending on the hill, if it is steep enough, you will indeed pick up speed.) As you let off the gas to maintain your correct speed down the hill, the PCM will give the engine less gas, shifting into overdrive will drop engine rpm further, but, you will still have to maintain a bit of pressure on the gas to maintain speed.

Even if the engine is turning 2600 RPM, if you are barely stepping on the pedal to maintain speed, you are not using much gas at all, as there is really not much of a load on the engine.

 

what does your 5r weigh. If it weighs any thing over 5000 and your getting 8.5 that aint to bad really.

 

Being as this Fan I put on now has to blow thru the a/c condenser before going thru the trans cooler I hope I didnt just waist my time with that mod?

Our 5'er is a 25 footer, dry 4650 lb.. Loaded now. I bet its right at 5500 lbs .
8 1/2 aint bad huh.. damn I would hate to see what bad is.

Sure wish that electric fan had been a 1/2 inch narrower.

 

I towed a 38ft goose neck trailer to KY this weekend. Used O/D for the whole trip, didnt even have to down shift in the mountains. Got 12mpgs.

Sorry, I had to.

 

alright, two thoughts from me on this deal. What about slipping it into neutral for the downhills? or, on my truck if you lightly cover the brake but not enough to apply them my TC will unlock. but that may speed the motor up more?!