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MPG Comparison Different Shapes

kltk1
Explorer
Explorer
Afternoon, folks. I know this is not easy to answer, but I was hoping those who've towed a lot could shed some light. Is there any reason to think I would get any better fuel mileage towing an Ascape trailer as opposed to the Taylor Coach pictured below? As you can see, the Ascape is much more of a bullet shape than the Taylor Coach and they both weight about the same. 1500-1800lbs depending on the model.

For reference, my tow vehicle is a 2016 RAM 1500 QC, 4x4, Pentastar V6.

Ascape Trailer


Taylor Coach
25 REPLIES 25

Boomerweps
Explorer
Explorer
Consider formula one car design. Also submarine design.
Submarines have rounded bulbous front ends. Originally submarines had pointy fronts but they were made to make the most speed surfaced, cutting the water surface. Water is a heavier medium but the same principles apply. Hence subs are now designed more for underwater flow and rounded, with rears having a long taper.
For the rear consider formula one race cars. They found that a lengthened and tapered rear smooths out the air flow for better speed (equating to better MPG).
BOTH concepts are used for Bonneville speed record racers after years of practical development. Rounded front ends and long tapered rears. Not practical for an RV, maybe the Oscar Mayer weinermobile ;). But MPG claims by those towing Airstreams and similar indicate rounded shapes work better even if the rear taper is minimal, it's still there.
Just my observations and opinion.
2019 Wolf Pup 16 BHS Limited, axle flipped
2019 F150 4x4 SCrew SB STX 5.0 3.55 factory tow package, 7000#GVWR, 1990 CC Tow mirrors, ITBC, SumoSprings,

stevemorris
Explorer
Explorer
there are so many variables when towing, case in point:

we went from a v6 Dakota towing 5000 lb to a ram 1500 hemi towing 7000 lbs. same 8500 km trip a year apart

trailers very similar shape, just your typical slightly sloped front, otherwise a big box on wheels. new trailer is 6 inches wider, 6 inches taller and 2 feet longer plus 2000 lb heavier

new combo used around 20% LESS fuel even though we were actually able to drive at 110kph on the freeway versus 100 with the v6(it struggled)

biggest difference in my mind was the v8 being lazy versus a hard working little v6.

of course technology came a long way in the 8 year difference between the trucks, hemi 8 speed vs the v6 4 speed
2017 Ram 1500 4door, 4x4, 5.7 l hemi, 8 speed
2008 KZ Spree 260

Groover
Explorer II
Explorer II
Your best bet for aerodynamics may be to use a tow vehicle that does the best job of shielding the front of the trailer from the wind. If towing with a PU you may want to add a camper shell that will help keep the wind off of the front of the trailer. Most semi's use a box shaped trailer with aerodynamics on the tractor. I sometimes get better mileage towing a trailer behind my notorhome than behind a pickup.

mooky_stinks
Explorer
Explorer
I towed a 6-8000lb TT and a 2000lb V-nose snowmobile trailer for 12 years and always got the same mileage with both. This was with several different trucks also. Like said before, it's all about frontal area. Not shape or weight.
2020 F150 XL Screw 4x4 6.5โ€box
3.5 ecoboost Max tow HDPP
7850 GVW. 4800 RAWR
2565 payload

2020 Cougar 29RKS 5th wheel

kltk1
Explorer
Explorer
Thank you to everyone for your input. It's amazing to think something that weighs half of what I have now is likely to get the same fuel mileage because of the shape. And it makes sense as we're essentially pushing a giant barn door through the wind. This is why forums are great.

ppine
Explorer II
Explorer II
Both are small and easy to pull.

D_E_Bishop
Explorer
Explorer
I agree with Bear II in that I don't worry about the money I spend for gas, I travel until what I have budgeted is gone and wait to accumulate more.

My figures may not be relevant and the amounts may be extreme but;

If traveling 10,000 miles pulling one trailer and average 16 mpg in comparison to the pulling the other trailer and getting 14.5 MPG, in the end assuming $3.00 per gallon cost, you will lose $0.01 per mile pulling the second type.

Of course there are the variables of purchase price differences and comfort and ease of driving, assuming all things being equal, $0.01 cents per mile isn't much. After driving 10K miles the difference is the 16 MPG trailer will get to go an additional distance of 90.50 miles.

I think I did the calculations correctly but maybe I did it wrong but if my figures are correct, what was the question again?
"I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to go". R. L. Stevenson

David Bishop
2002 Winnebago Adventurer 32V
2009 GMC Canyon
Roadmaster 5000
BrakeBuddy Classic II

prichardson
Explorer
Explorer
The top one will be the same as what you are using now MPG wise. The other may add 1 MPG. However, for the stated way you use it I would look at interior size and layout as the determining factor. Unless you run long distances frequently fuel usage is really not that big of an expense.

blt2ski
Moderator
Moderator
The Ascape might do better for another reason not brought up. It has smooth walls. Can you get smooth fiberglass walls with the Taylor? while slightly heavier, the smooth walls will net you better mpg's.
IF you truly want better mpgs, get a tent trailer or popup of some sort from a pull behind stand point. Or an Airstream as mentioned. A member that I have not seen posting in awhile, said an Airstream got the best mpg's, as he was an RV hauler with his Dodge pickup. WORST was a ball mount with aluminum siding. Next best to an Airstream was a smooth walled 5W with no front bedroom slide, slightly sloped roof etc.
On Semi's, Aerodynamics can relate to upwards of 30% plus or minus HP needed to move a load at a given speed. BUT, with this in mind, it will take a LOT of miles to make up the cost for some wind reduction devices.

Marty
92 Navistar dump truck, 7.3L 7 sp, 4.33 gears with a Detroit no spin
2014 Chevy 1500 Dual cab 4x4
92 Red-e-haul 12K equipment trailer

kltk1
Explorer
Explorer
aftermath wrote:
Yes, the aerodynamics of a trailer makes a huge difference. That said, you canโ€™t really judge this simply be the shape of the front. There are many factors to include here.

I towed a white box hybrid, 20ft long with a GVW of about 5000 lbs. I changed to an Airsteam, 25 ft long with a GVW of about 7000. I got the same mileage towing with the same truck, 11-12 mpg.

After a couple of years I added a bike rack to the back of the trailer and noticed a drop in mpg. Now I get 10-11 and it doesnโ€™t matter if the bikes are on the back or not! Airstreams are designed to reduce turbulence at the back. Adding the rack sort of messed this thing up.

Good luck with your decision. My thought on all of this is that you should get the trailer you like the most. A mile here or a mile there isnโ€™t going to make you happy or sad.


Thank you. Very much in agreement about getting something we like.

aftermath
Explorer II
Explorer II
Yes, the aerodynamics of a trailer makes a huge difference. That said, you canโ€™t really judge this simply be the shape of the front. There are many factors to include here.

I towed a white box hybrid, 20ft long with a GVW of about 5000 lbs. I changed to an Airsteam, 25 ft long with a GVW of about 7000. I got the same mileage towing with the same truck, 11-12 mpg.

After a couple of years I added a bike rack to the back of the trailer and noticed a drop in mpg. Now I get 10-11 and it doesnโ€™t matter if the bikes are on the back or not! Airstreams are designed to reduce turbulence at the back. Adding the rack sort of messed this thing up.

Good luck with your decision. My thought on all of this is that you should get the trailer you like the most. A mile here or a mile there isnโ€™t going to make you happy or sad.
2017 Toyota Tundra, Double Cab, 5.7L V8
2006 Airstream 25 FB SE
Equalizer Hitch

kltk1
Explorer
Explorer
rexlion wrote:
troubledwaters wrote:
Seeing as both are basically the same in the back, the frontal area is going to be the key. Max total height x max total width.
Yep, just what I was going to say.

Based on alll the towing I have done and reading in rv forums, I will predict that if both have equal frontal area, slope notwithstanding, the mpg with the two will be within1/2 mpg of each other. Likely 11-12 . If you tow a Scamp or Casita, you could get more like 15-16 assuming same speed and conditions. The reason is, the egg trailers sit lower and are narrower and are rounded on all corners, all of which reduce frontal area and also somewhat ease the flow of air behind the trailer for less vacuum.



This is excellent and what I was hoping to find out. Currently, I tow a Flagstaff 23LB at about 3800lbs and get from 10-12 depending on conditions at 60mph. I was hoping to see about 15-16 with the smaller trailers at about half the weight.

Thank you very much.

rexlion
Explorer
Explorer
troubledwaters wrote:
Seeing as both are basically the same in the back, the frontal area is going to be the key. Max total height x max total width.
Yep, just what I was going to say.

Based on alll the towing I have done and reading in rv forums, I will predict that if both have equal frontal area, slope notwithstanding, the mpg with the two will be within1/2 mpg of each other. Likely 11-12 . If you tow a Scamp or Casita, you could get more like 15-16 assuming same speed and conditions. The reason is, the egg trailers sit lower and are narrower and are rounded on all corners, all of which reduce frontal area and also somewhat ease the flow of air behind the trailer for less vacuum.
Mike G.
Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. --Frederick Douglass
photo: Yosemite Valley view from Taft Point

troubledwaters
Explorer
Explorer
Seeing as both are basically the same in the back, the frontal area is going to be the key. Max total height x max total width.