I am new to this forum so I hope this is not an old question/problem.

I have a 2006 3500 SRW 2WD Mega Cab with the 5.9L diesel engine and auto trans. I get anywhere from 19 -22 mpg empty but am disappointed in my towing mileage which averages around 8.5 mpg. I have 57K miles on the truck mostly towing.

My TT is 34' (box is 30'), weighs about 7800 empty, probably close to 10K packed and traveling.
I usually set my cruise control at 65 or 70. Mileages on my last trip were:
7.59, 8.02, 9.10, 8.54, 8.85, 8.66, 7.75, 10.28, 8.48 tank by tank or 8.46 MPG for 1248 miles overall.
My problem may be my own expectations. I was expecting to get >12 MPG while towing. I'm completely happy with the empty mileage but most of my driving is towing.

The Dodge dealer tech has told me that the parking brake is worn and this could affect the mpg. According to him, there is a sensor on the parking brake that will adjust the fuel if it senses the parking brake is dragging (even if it's not) and this can be caused by worn brakes. The tech did say there is a seperate parking brake system, with 4 wheel drum brakes they do not use the disc brake as a parking brake. Maybe that's why they now call it a parking brake rather than an emergency brake?

I am going to fix the parking brake because it is mostly useless now. We'll see if that makes any improvement. Frankly, the dealer seems clueless or uninterested, not sure which.
Anyone ever had a similar problem? Anyone have some advice on what to check?

 

This is the first itme I have heard that there is a sensor that adjusts the fuel based on the parking brake status/condition based on wear. So, are your brakes down to whatever wear point that would make thsi happen??

Seriously, since I do not own an auto tranny truck, but have read a lot of the auto tranny threads, are you using the two/haul mode?? Using it vrs not using it may affect your mileage.

I get 12-14 and sometimes 16 mpg's towing. It depends on the conditions and the load weight. I have not experienced fuel mileage less than 12mpg while towing, and that is my GN flatbed with 14-16K onboard in the mountains driving some steep grades.

Something as simple as tire pressure on your tow vehicle and the trailer itself can dramatically affect your fuel mileage. Having your load too forward on the tow vehicle, high pin weight, can affect your mileage. I always try to make sure my load is balanced between the vehicles.

A dragging parking brake will certainly cause a mileage problem. But when you have released the brake it should not be dragging. If anything, the cable would stretch out after a couple years use, not shorten to cause dragging.

CD

 

I average 10 mpg towing my 5th wheel that weighs around 10k, sometimes higher mileage but have not seen less than 10 yet.

 

My Camper is 13000# +/- loaded down, I average between 11 and 12 miles per gallon at about 70 mph.

 

Did you use your T/H mode when pulling a loaded trailer? That is whats it was made for and also when loaded make sure you don't try to get up to road speed as fast as you would if empty. So if you take it easy on the go pedal and you should see better fuel mileage when towing.

JMHO

 

I get anyware from 13.5 to 16 MPG on paper towing my 25ft TT 7500lbs, my mpg went up towing when i installed the XZT tow box, and as long as I keep it at 60 with tow haul and cruise, mine sure drop`s when I get up closer to 70, suprising the differance.

 

How about maybe a issue with wind resistance? Pulling about 11k I'm about 10.5 to 12.Pulling 1/2 that but a blount nose trailer I get the same mileage.I use to have customers that pulled those houses behind them and they swore that the WING added to the roof of their trucks made a huge differance.So much so they could feel the differannce with that big air deflector on and off.

 

Do you get the same towing mileage in summer & winter? I find that I get 2 - 4 mpg less in winter, due to winterized diesel.

 

i dont think mine has any type of drum braking system anywhere on it

brett

 

I am with Brett, I don't have any drum type brakes on mine. someone is blowing smoke up your tail.

 

Here's a quote from the service manual -
"PARKING BRAKE
DESCRIPTION
The parking brakes are secured to a support plate (1)
and operated by a system of cables and levers
attached to a primary and secondary shoe (2) positioned
within the drum section of the rotor.
The drum-in-hat design utilizes an independent set of
shoes (2) to park the vehicle."

There are pictures of the drum, which is inside the rotor assembly. If you have 4 wheel disc brakes then you probably have this 'drum in hat' parking brake that is seperate fomr the disc brake with it's own brake shoes.

 

BS..... Your problem is wind resistance and or a gearing issue. Another thing to do is try a different fueling station. I have found out that some stations fuel is better than others, hence better mileage. If you are locking out OD that is part of the problem. With an 06' just throw it in Tow/Haul (should not do OD lockout with only one push) and go. On a windy day the wind will cause you to suck up the fuel if pulling against it....


By your empty mileage it looks like you have 3.73's. Pullinig heavy in the hills is gonna suck up the fuel if you don't stay in OD.

 

I have a 2003 Quad Dually long bed 5.9L with automatic and tow a high nose 14K fifth wheel. I also have an Edge Attitude w/4" pipe and K&N air filter. Towing at 70 on flat land I average 11.5 to 13 depending on angle of foot. I run a 3:73 rear dif and normally tow in overdrive unless mountains or steep grades call for direct. If you're dropping that much in fuel mileage something is not right. What rear end ratio do you have?

 

I have the 3:73 as well.

 

Where do you live?