very poor to aweful fuel mileage when towing

[rod7515]

I decided to post in the engine performance forum for my issue. I have a 2011 5.7 ram 1500 with only 44,000 miles. My gearing is 3.21 and its an automatic trans with 4wd. Extended cab. I tow a 24' enclosed car trailer that weighs approx 3300 lbs. the car is a 66 Dart that weighs approx 3100 lbs. ive had the truck for just over 3 years. The truck dodes not seem to struggle when pulling. I have done 4 trips over the 3 years I've owned the truck. Each time my fuel mileage has been 7.5 - 8 mpg. All trips have been mostly highway and no large mountains to climb. I travel at about 55 mph.
The only issue i am aware of with this truck is that when not towing i can feel a slight surge at around 35-45 mph when lightly accelerating.
A few more things, i have set my trk up with air bags so I can keep the truck at the same ride height as it always has and I have made the tongue weight as light as possible. I can not move the car back any farther in the trailer and I am running just over 1000 lbs of tongue weight. The trailer sits level when hooked up.
So tell me, am I doing worse then most Ram owners and what options do I have. what improvements would you do if this was yours?
Thanks Rod

 

[Burla]

It about 1/2 the mileage when you tow, maybe a little more. 3.21 with an rfe for the hemi is kinda of a poor set up for towing that heavy. That isn't heavy for a ram, but it is heavy for those gears. I would look up if you are over weight for those gears. I'm not sure it will pay for itself with mileage, but moving to a 4:10 or better might extend the life of your trans, and may help a bit with mileage.

 

[Burla]

One example I see is this..

Ram 1500, 5.7-liter V8, crew cab, short bed, 2WD, 17-inch wheels, 3.21:1 axle 5,700

So according to this tow guide max you should be is 5700 pounds with that set up. I can't find your exact set up, research that. It's not a huge issue depending on state laws, but yeah worth researching.

 

[kurek]

Sounds like pretty normal fuel mileage for a gas powered pickup pulling a 6500lb brick. While I'm not really a fan of diesel on a light duty vehicle the place they really shine is efficiency under constant load - and in contrast a gas powered truck is always going to get pretty bad mpg while towing.

Do you have larger than stock sized tires? If so, have you recalibrated the truck to match them?

 

[crash68]

^^^what he said about diesel/gas
Yeap as I've said before it's the spark plugs that cause the lower fuel economy.
At times I tow a similar 24' enclosed car hauler (3K lbs empty) and that drops me down around the 16 mpg range, with my 18' boat which is 3200 lbs in the trailer the mpg drops to about 20 mpg. It's the amount wind drag of the trailer that eats up the fuel economy.

 

[mtnrider]

You simply are not going to get better fuel mileage with what you have. You are pretty much maxed out for your truck and on top of the weight that enclosed trailer has a lot of wind resistance. Be happy it's not worse.


.

 

[dhay13]

What they said. First you are maxed out (or very close to it) on towing capacity. Second, that is about normal MPG for that. I had a 2013 1500 5.7 with 3.55s and towing my sons ~7500lb travel trailer I got about 6.5-7.0 MPG hand calculated. I towed it 150 miles and had to stop about 10 miles from my destination cause I was on fumes and probably wouldn't have made it the rest of the way. My max tow capacity was 8600lbs. Towing that same trailer at 8100lbs with my 2018 2500 6.4 4.10's I get about 7.5 MPG, so slightly better mileage (but still sucks). It is what it is. Towing a large brick will kill mileage. It's more about the (non) aerodynamics of the trailer than it is about the weight.

 

[tjfdesmo]

Box trailer=Parachute

 

[AFMoulton]

^^^^^Basically what everyone has already said. You are towing a wall behind your truck


2018 Ram 2500 6.4L 4x4
Amsoil SS 0W-40

 

[RLJ10X]

Rod, you have a low mileage '11, which is relatively inexpensive to regear. So, regear. 3.21s stink. Outloud.

Do 4.10s like I did, or better yet, 4.56s.

Try backing your car into the trailer rather than pulling it in; See if that helps. You ought to get that tongue weight down a bit.

I pull a John Deere 3038E with loader and a 5 foot slasher on a 16 foot SureTrack Tilt trailer. So I'm pulling about 6100 pounds. But I have much less wind drag than you. My truck pulls my loaded trailer like that's what it was built to do.

 

[dhay13]

Re-gearing will definitely help but won't raise your tow capacities. If you are over now you will still be over with steeper gears. Can't change your max ratings unless you buy a different truck

 

[Burla]

Re-gearing will definitely help but won't raise your tow capacities. If you are over now you will still be over with steeper gears. Can't change your max ratings unless you buy a different truck

im not sure why you say that, any tow guide shows the only thing that determines different tow ratings within any truck style is the gear ratio. Same exact truck with 3.92's is rated almost double the weight. look up any tow guide with an rfe trans, you can see it.

 

[Burla]

just cut and paste from tow guide, going from 3.21 to a 3.92 increases towing rating quite a bit. you see middle gear 3.55 splits the baby as well.

Ram 1500, 5.7-liter V8, regular cab, short bed, 2WD, 17-inch wheels, 3.21:1 axle 6,100
Ram 1500, 5.7-liter V8, regular cab, short bed, 2WD, 20-inch wheels, 3.21:1 axle 5,950
Ram 1500, 5.7-liter V8, regular cab, long bed, 2WD, 20-inch wheels, 3.21:1 axle 5,900

Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 20-inch wheels, 3.92:1 axle 8,850
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 17-inch wheels, 3.92:1 axle 10,250

Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 20-inch wheels, 3.92:1 axle 10,200
Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 17-inch wheels, 3.55:1 axle 7,900
Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 20-inch wheels, 3.55:1 axle 7,850
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 17-inch wheels, 3.55:1 axle 7,750
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 20-inch wheels, 3.55:1 axle 7,700

 

[dhay13]

just cut and paste from tow guide, going from 3.21 to a 3.92 increases towing rating quite a bit. you see middle gear 3.55 splits the baby as well.

Ram 1500, 5.7-liter V8, regular cab, short bed, 2WD, 17-inch wheels, 3.21:1 axle 6,100
Ram 1500, 5.7-liter V8, regular cab, short bed, 2WD, 20-inch wheels, 3.21:1 axle 5,950
Ram 1500, 5.7-liter V8, regular cab, long bed, 2WD, 20-inch wheels, 3.21:1 axle 5,900

Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 20-inch wheels, 3.92:1 axle 8,850
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 17-inch wheels, 3.92:1 axle 10,250

Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 20-inch wheels, 3.92:1 axle 10,200
Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 17-inch wheels, 3.55:1 axle 7,900
Ram 1500, 5.7-liter V8, regular cab, short bed, 4WD, 20-inch wheels, 3.55:1 axle 7,850
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 17-inch wheels, 3.55:1 axle 7,750
Ram 1500, 5.7-liter V8, regular cab, long bed, 4WD, 20-inch wheels, 3.55:1 axle 7,700

Yes but legally that truck with that VIN is locked in by the numbers tied to that truck. Your truck has a GCWR that cannot be legally exceeded. A truck with 3.21's have a lower GCWR than a truck with 3.92's. When you hook up a trailer and get on the scales it doesn't matter what gears you have, if you are over the GCWR for that VIN then you are no longer legal. GVWR and payload will be the same for either gear so that won't matter but your GCWR will be different. Only way to change it is to get the truck re-certified and from what someone posted here it cannot be done by a consumer, only by a professional shop and I'm sure the process won't be easy or cheap.

 

[RoadRamblerNJ]

Yes but legally that truck with that VIN is locked in by the numbers tied to that truck. Your truck has a GCWR that cannot be legally exceeded. A truck with 3.21's have a lower GCWR than a truck with 3.92's. When you hook up a trailer and get on the scales it doesn't matter what gears you have, if you are over the GCWR for that VIN then you are no longer legal. GVWR and payload will be the same for either gear so that won't matter but your GCWR will be different. Only way to change it is to get the truck re-certified and from what someone posted here it cannot be done by a consumer, only by a professional shop and I'm sure the process won't be easy or cheap.

^^^^^^^^THIS^^^^^^^^

Sent from my SM-N910V using Tapatalk

 

[crash68]

(golf clap) yet another fine job of the payload police turning this into a

you do realize that @rod7515 was asking about was fuel economy.

 

[crackerjack1957]

Maybe there is a weight limit but the guide defiantly shows how much better gears help in towing.

 

[AFMoulton]

Two things:

1) You MIGHT get a little better gas mileage with better gears, a wall is a wall, and box trailers and travel trailers are awful behind trucks.

2) Change gears to help it tow easier, but if you wreck and they really want to investigate and you are over weight for the VIN, no insurance company or lawyer will give two ***** what you did to help it “tow better”. This will be especially true if you are overloaded and a fatality occurs during an accident.

Call us/them payload police all you want, they are not wrong.


2018 Ram 2500 6.4L 4x4
Amsoil SS 0W-40

 

[Burla]

More reason to pay attention to gear ratio when you buy your truck, 3.21's shouldn't be bought if you are planning towing anything above a landscape trailer, especially with an rfe. The OP not only asked about gas mileage but what we would do, and learned something he probably didn't know, that he is towing weight above the tow rating.

 

[RedSRT4Me]

Gears will help get you back into towing fuel economy.

4.56 combined with the 8speed can't lose.



Need to get 5.13's on the Yota. 4.30's 6 speed and 37's is a dog