Only 6.5 mpg towing enclosed trailer (only 3,700lbs)!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

mtofell

Senior Member
Joined
Mar 18, 2014
Posts
2,631
Reaction score
2,269
Ram Year
2014
Engine
Hemi 6.4
The trip home (without trailer) I ran the same 75mph and got just under 18mpg. I just expected/hoped for better mpg than I'm getting.

Something here doesn't add up. There is no way you lose 11.5 MPG pulling a low-profile 3700# trailer. It may be something you aren't aware of such as headwind while towing and tailwind while not. Elevation rise getting there and downhill coming home?

I've towed a few cars on trailers which is somewhat close to what you were pulling and my MPGs would go from 17ish to 12ish.
 

crash68

ACME product engineer
Staff member
Administrator
Supporting Member
Joined
Mar 20, 2016
Posts
10,698
Reaction score
16,705
Ram Year
2015
Engine
3.0 EcoDiesel
Something here doesn't add up. There is no way you lose 11.5 MPG pulling a low-profile 3700# trailer.
It's how fast he is trying to pull the trailer, as noted in his post he set the cruise at 75 mph. In a gasser your going to suck fuel faster than an alcoholic with free booze, with all that wind load. A V-Nose doesn't make much of a difference in fuel economy, it does make them pull smoother with less sway though.
 

mtofell

Senior Member
Joined
Mar 18, 2014
Posts
2,631
Reaction score
2,269
Ram Year
2014
Engine
Hemi 6.4
It's how fast he is trying to pull the trailer, as noted in his post he set the cruise at 75 mph. In a gasser your going to suck fuel faster than an alcoholic with free booze, with all that wind load. A V-Nose doesn't make much of a difference in fuel economy, it does make them pull smoother with less sway though.

I get the speed as a factor but I just don't see that small of a trailer cutting the MPGs in 1/3. He said he was going 75 both with and without the trailer. If he were going 60 w/o the trailer and 75 with I might believe that big of a change. Hauling my 11,000# sail of a 5th wheel doesn't even reduce my MPGs by half.
 

crash68

ACME product engineer
Staff member
Administrator
Supporting Member
Joined
Mar 20, 2016
Posts
10,698
Reaction score
16,705
Ram Year
2015
Engine
3.0 EcoDiesel
He stated a V-Nose trailer, those are usually tall enough to stand up in. If he's using a clam shell snowmobile trailer then there is something wrong. The 3.21 gearing would explain a larger than normal difference in fuel economy between
towing vs driving.
One thing that really helps with a fiver is the air doesn't drop down after the cab, a lot continues up and over in comparison to tag along. You probably don't get close to 18 mpg as an unloaded fuel economy either at 75 mph.
The weight doesn't really punish the fuel economy unless your pulling a lot of grades. Going from a 3K lbs enclosed to an 8K lbs enclosed only hits me about two mpgs unless it's windy.
 

mtofell

Senior Member
Joined
Mar 18, 2014
Posts
2,631
Reaction score
2,269
Ram Year
2014
Engine
Hemi 6.4
One thing that really helps with a fiver is the air doesn't drop down after the cab, a lot continues up and over in comparison to tag along.

Yeah, on an RV board once I read where someone had done some tests or research and 5th v TT was nearly identical for the same weight. Even though the 5th is taller, the wind basically has to be broken through twice with truck and TT. I wonder if anyone notices a difference with a shell on their truck versus not? I suppose even with a shell the wind would still get caught up on the front of the trailer after it whips around the shell. The 5th really does cut through the wind as a single unit.

Going from 7000# TT to 11,000# 5th my MPGs maybe went down by 1, if that. I honestly don't really know what I get for MPGs most times. I just hand the gas guy my credit card and bend over.
 

NDanecker

Senior Member
Joined
Mar 1, 2019
Posts
128
Reaction score
193
Location
Earth
Ram Year
1999
Engine
123
I wonder if anyone notices a difference with a shell on their truck versus not?

I had a Toyota Pickup years ago and purchased a shell about 1 year into owning the truck. Although I never did mileage calcs I noticed a huge difference pulling a cargo trailer with/without the shell at highway speeds. It had the 4 cycle motor so it was light on HP/TQ so it noticed it.
 
OP
OP
M

Mike 67

Junior Member
Joined
Nov 14, 2019
Posts
4
Reaction score
2
Location
S.E Wis
Ram Year
2019
Engine
Hemi 5.7
Something here doesn't add up. There is no way you lose 11.5 MPG pulling a low-profile 3700# trailer. It may be something you aren't aware of such as headwind while towing and tailwind while not. Elevation rise getting there and downhill coming home?

I've towed a few cars on trailers which is somewhat close to what you were pulling and my MPGs would go from 17ish to 12ish.

I know the mpg drop is crazy. The V-nose I have is not low profile. It's tall enough for me to stand in. It is also a wide trailer (2 sleds fit side by side). Something about it's aerodynamics (or lack there of) is strange. I used to own a 32' Jayco camper (bumper pull) that was just over 8K lbs. My Duramax would deliver the same mpg pulling that heavy camper.
As I mentioned it was a windy day. When I pull my sleds home for the summer I'm going to hang in the slow lane at 60-65 and see how much of a difference it makes. If it's windy I'll get a more accurate comparison.
 
Top