Fuel mileage comparisons between 5er and travel trailer - Diesel Forum

dieseldrive · 08-09-2006, 10:02 PM

Do any of you have any hard data on the difference in fuel mileage to expect when dropping from a 32 ft 12K loaded weight 5er to a 30 ft travel trailer that should gross arond 8500 lb loaded? I am considering giving up the 5th wheel to make hauling my cycles in the back of the truck (wife won't go for a toyhauler) and was wondering if I would gain any fuel mileage.

barrelhorses · 08-09-2006, 10:05 PM

[img]/ubbthreads/images/graemlins/shrug.gif[/img] I doubt there would be too much difference. Maybe some fuel savings, but probably not enough to make a difference.

Alan_Hicks · 08-09-2006, 10:59 PM

I wouldn't anticipate any real change in fuel mileage. The lighter TT is going to hit just as much wind as your fifth-wheel, so the change in weight isn't likely to make much of a difference. You'd likely see a significant mileage gain if you pulled a pop-up, but I don't think they make a pop-up that will compare with your current 32 foot fifth wheel.

twobit · 08-10-2006, 10:19 AM

Our fiver has a stand-up bedroom so it is 12 feet tall which translates into a big wind load. I have seen basically three heights of fivers ...those where you have to crawl into the front bed, those where you have to bend over next to the bed, and those where you can stand up next to the bed. A bumper pull trailer is shorter than most fivers so I would think wind load would be lower for it than a fiver giving better fuel mileage at highway speed.

Cool_Canuck · 08-10-2006, 11:58 PM

Drag has more effect than weight on fuel milage. Just guessing, but I'd bet you see more than 20% improvement in milage from a high fiver to a TT.

tsaelens · 08-11-2006, 12:32 AM

[ QUOTE ]
Drag has more effect than weight on fuel milage. Just guessing, but I'd bet you see more than 20% improvement in milage from a high fiver to a TT.

[/ QUOTE ]

I'll take that bet.

What you guys aren't putting into the equation is that the nose of a 5er in the bed changes the aeros of the entire vehicle. A truck pulling a tt still has the wind of the truck coming down over the tailgate heading down hitting the trailer. So a TT has what about 7 feet of surface height in front, and a High profile 5er can be as tall as 13.5. And I don't know about you guys but my truck cab is almost 7 ft high, 13.5 minus 7 is 6.5 ft of surface height. Pretty close to a wash in my book.

Main reason I can't see 20% improvement is this.... Let's say he's getting 9-10 mpg pulling the 5er. Add 20% and you are almost 11-12 mpg. I barely get 12 with a dinky little 7x14 cargo trailer that weighs 6K lbs. And he's gonna get that with a TT that's taller and wider and outweighs me by 2500 lbs? In addition I get about 10 mpg with the 24 ft enclosed trailer at 10K lbs.

Trinity

DA28 · 08-11-2006, 03:57 PM

I went the other way
We had a 27ft TT grossed around 8500
Went to a 35 ft fiver grossing 12k +
noticed maybe .5 mpg loss now that was with my 7.3 .... just got an06 6.0 haven't towed with it yet

teamroper60 · 08-14-2006, 12:19 AM

Not really a good comparison, but two weekends ago, I towed a 23ft TT and got 12mpg. This past week, I bought a 29ft mid profile (the stand up, but duck height) 5er. With the 5er in tow, I got 11.5 but I was in far hillier terrain. Looks to me like the two were a wash mpg wise and the dry weight of the 5er is more than the wet weight of the TT....

Tina · 08-14-2006, 10:58 AM

I pull a 30'TT with my truck. It's an older trailer (2000) and more boxey looking, about 9k lbs loaded up. I do have a cover on the bed of my truck. Milage is between 10 - 12 mpg and I'm usually doing close to 68mph.
Lately I've been out looking at some of the new TT's and noticed some of the new shapes the manufactors are doing to the fronts of these trailers. One is a wedge and the other is very curved back. Both of these look like they would move the air flow out around the trailer much better than my box is doing and that should cause increased milage numbers.