I am a first time truck owner. 2005 ram 2500 turbo diesel. My questions are:
How much can i tow with this truck? (fifth wheel)
When towing and using the "tow haul" gear, can i still down shift (auto trans) to lower gears when going down very steep long hills?
thank you for your help
Al

 

Go weigh your truck fully loaded, subtract weight from 9000 GVWR. Take the leftover payload number and multiply buy 4 or 5. That will give you a trailer with 20-25% pin weight. Otherwise, you truck was rated for about 13000 lbs depending on equipment.

 

repsman, WELCOME!

IIRC:
~23k Gross Combined Weight Rating (GCWR) = Truck weight + trailer weight + goodies in the truck + goodies in the trailer

As mentioned, ~9k Gross Vehicle Weight Rating (GVWR, this is on the driver's door sticker) = Truck weight + pin weight + goodies in the truck, or Pin Weight (max legal) = GVWR - (Truck weight + goodies in the truck)

Goodies in the truck is defined as people, foodstuffs (if there's a lot), in-bed fuel tank, etc.

Goodies in the trailer is defined as foodstuffs, camping gear, any extra supplies, and what-not.

Let me make a distinction here....I am referring to the manufacturer weight limits. AKA legal weight limits. You will see/hear of people towing any where from just over to WAY over these weights. Do so at your own risk. Also, be aware that most RV dealers will tell you anything to make the sale. Your best defense here is education!

HTH

Tony

 

Thanks for the info. Does anyone have answers/opinions on the part of the question regarding using tow haul and still down shifting?
thank you
Al

 

So far I have had good luck turning off o/d going downhill. However a pacbrake is next on my shopping list. An old rule of thumb is to go down a hill in the same gear it took to get up it.

Taver

 

He has an '05....I've been hopin others with '05's would chime in. I think '05's only had Tow/Haul...our '06's have T/H and 4th lock out.

Tony

 

You can flash the 05 controller and then "enable" OD lockout. That will make it like the earlier trucks where you could lock out the od when the button is pushed. Won't give you both options like the 06 up.

 

Locking out the OD helps slightly, until the RPMs come right back up. Downshifting from there works just the same. These diesels don't do much for holding ya back. Watch your spacing from other vehicles and let the trailer brakes do a little more than usual.
We've been doing a 15k 5er on this 3500 for 2 yrs. with a few close ones.
The new trailer comes in next week with DISC brakes on it!

 

A couple of you have used the term locking out the od. What is this?
Thanks
Al

 

On the '06 automatic trucks, you have the option of tow/haul mode or OD (4th gear) lockout. By locking out 4th gear, the computer keeps the trans in 3rd gear.

The benefits of locking out 3rd is increasing the RPM, lowering the EGT, and making the engine work less (read lugging). For example, I can tow my 3k boat up a 7-8% grade at 65 in 4th, but my EGT's are topping 12-1300F and RPM's at about 1900. By down shifting (lockout OD), rpm's come up to ~2400 and EGT's drop to ~900. Is there a prefferred RPM? Some say lower; some say higher. I try to keep the EGT's as low as possible. In general, lower EGT, less fuel burnt.

Oh, and fill out your signature so we know what truck you have; it'll; help when you have truck model/year specific questions.

Tony

 

So if I keep the rpms up to 2000 or higher when towing you think that the mpgs will be better than if the truck is pulling 1600 in OD

 

I was not trying to imply any mpg impact. OTOH, I have not towed enough to try to gauge that. Or should I say that I haven't been willing to burn enough fuel to try to measure that. Or, both!

There's also a handful of variables that will affect it; Cruising speed, grade, overall condition of the truck, tire pressure, age of oils (engine, diff, trans), fuel quality, fuel filter, air filter, and mostly load!

In general, lower RPM = less fuel; What complicates this analogy is boost. If we had a clear understanding of boost-fuel-load curve, we might be better drivers for the economy side of life.

All I was trying to say, was, if you are towing flat land, try to keep the revs as low as possible. Up significant grades, you are likely to have to keep the revs higher to keep the EGT's down. And, yes, my truck is bone stock, sans the gauges. With the EGT gauge, I am able to drive a little easier on the motor to keep the temps down. Even if you have no plans for performance (like me), I still advocate gauges. More information is NEVER a bad thing!

HTH

Tony

 

IMO theres a balance. like tony was saying, lugging the motor is wasting fuel, but turning high rpms, takes alot of fuel also. my sweet spot is around 1800-2000 rpms.

brett

 

i've noticed i can get almost 14 driving at 60. thats w/17k gvw. at 65 i drop to about 10.

john, 95 cc, lb, 237k, auto