Will it hurt to tow in Overdrive??

[SixPac]

I have a 2001, 2500, 4X4, 10,000mi, 3. 55 gears (might be 3. 54, I can't remember), shortbed, Auto w/overdrive.



I tow a 20ft car hauler, wt. 7,500lbs. , loaded. The trailer's height is a couple of feet above the truck which does provide quite a bit of drag. Total wt. , truck, trailer, and car approximately, 15,000lbs. I live in Missouri so everywhere I tow is more or less flat, no mountains.



It seems to "lug" the engine at times, towing in Overdrive plus I'm sure it wouldn't be good for the transmission either. I've wanted to keep my rpm down to avoid any engine damage, etc. I try to keep my rpm around 2,000, I think that is around 70 or 75 mph in overdrive. A little faster than I like to drive while towing but I need to keep it there to stay within the power band. However, when I take it out of overdrive the rpm shoots up to 2,500 - 2,700, which I think is about 60 or 65mph. That seems like the engine is turning very fast.



Question:



Under my weight conditions, what would be the optimal rpm range both for gas mileage and engine/transmission protection while towing.



I want to know what other people are doing, towing in overdrive or not.



Any and all suggestions welcomed.



Thanks,



Bob

 

[JGarcia]

Bob,

I try to maintain RPM's above 1700 when towing my 8300 lb trailer. lugging would become more of a problem below that. Also, when I'm pulling up steeper mountain roads, I find that with my 4:10's I'm pretty frequently in the 2500 RPM range. The new 24 valve's actually like a higher RPM than the older 12 valvers, I don't think there's any problem with this. As far as keeping it in overdrive, it's fine to pull in OD, especially on flat terrain, my truck's "sweet spot" seems to be around 2000 to 2200 RPM, where I maintain good pull and decent mileage, in or out of OD.

Hope this helps.

Regards, JRG

 

[WadeMetzinger]

Sixpac, I have the exact same truck and trailer for the most part:



2001 3/4 auto, club cab, short-bed, 4x4, 3. 54 gears, bone stock

2000 24' Pace Enclosed trailer, 8,000 lbs with my car in it



I always pull in overdrive, I don't think I've every towed out of OD. I've pulled my car all over the country in OD. I usually tow at 80 mph on the interstates but I'm working the engine but that's what it was designed for. If I tow 70 - 75 I get much better fuel mileage. I live in Tulsa and I've been to Ozark several times, St Louis, Memphis, Shreveport, Dallas, Topeka, KC, Joplin, Paris TX.



I've got 50k on my truck and I haven't done anything to it except for the normal maintenance: changed the oil, transmission fluid and differential fluid.



I still have the original brakes and tires on my truck and I've never rotated the tires. The rear tires are starting to wear down but that's because I tow with a lot of tongue weight and tow a lot in the summer at high speeds.

 

[Pull'nOld Iron]

Works For Me

I second the opinions here with the following exceptions.



I tow, about 8K to 10K, in OD and switch out of OD when in town or construction traffic and when pulling hills that seem to lug things down. I have the 3:54 gear also and was stock till last month. Didn't look to see if you have a transmission gauge but if not, get one. I reccommend the purchase of a '95 transmission line with the sensor port built in. This is better in the long run than a manifold set up.



By the way, flat Missouri???? Where you at man. Of course it's all relative. I travel up Joliet on either 55 or 57 and there are certainly some hills, not mountains though, to pull on those trips.



Anyway, good luck!

 

[BK]

besides the lugging issue,

if in hills and stop and go, turn off the OD.

If on a nice straight, fairly flat long run, you can tow with OD on.

It's when it starts to hunt or constantly down shifting out of OD from using the go pedal in traffic or hills... that it starts to be a problem for the transmission.

 

[dodger22]

I pull a 10,000lb 5'er in overdrive wherever possible. I like to wait until the rpm is about 2200 before engaging o/d. You can be driving on the flat into a headwind and will lose speed, when that happens lock out o/d. Gets a bit noisy in the cab with the higher rpm but the ol' Cummins likes to wind out.



When driving up a bit of hill or incline you might see the rpm start to drop, try to anticipate it, back off the go-pedal and lock o/d out.



With your weight you should be okay.



Hope this helps.



Richard