Towing MPG question

[tbrew100]

Hello, I tow a Mini Lite 25DS with a F150.
I was wondering if anyone has experience towing with a tonneau cover vs a truck cap.
How much does the truck cap improve MPG (less wind resistance against the front of the trailer) than a tonneau cover!

Thanks in advance!

[merlinhomeauto]

I removed my cap and gained 3MPG.

[aceinspp]

I use a tonneau cover on my truck to keep the wind from hitting tailgate. It does improve mileage. Later RJD

[spock123]

Originally Posted by aceinspp

I use a tonneau cover on my truck to keep the wind from hitting tailgate. It does improve mileage. Later RJD

I had a tonneau cover on my 2500 and never saw a difference in fuel mileage. It was good for putting things in you didn't want everyone to see.


Sent from my iPhone using Forest River Forums

[M&K Hoffman]

Originally Posted by tbrew100

Hello, I tow a Mini Lite 25DS with a F150.
I was wondering if anyone has experience towing with a tonneau cover vs a truck cap.
How much does the truck cap improve MPG (less wind resistance against the front of the trailer) than a tonneau cover!

Thanks in advance!

I have a cap on my truck and a V nose trailer and it seems the only way to improve gas mileage is to always tow downhill with a tail wind!

[davel1971]

want to gain mileage? Leave the trailer home. The wind your pushing with that is the problem, not the tailgate.

[BandJCarm]

I've had a tonneau cover of one kind or another on my last 4 trucks. I put them all on after getting the truck. I never noticed one iota of difference in MPG either way, pulling or not pulling.

[timfromma]

I gained about 2MPG after I installed my tonneau cover when I'm not towing.

[tbrew100]

Thanks for all the feedback, my original question was if anyone had experience with having a tonneau cover vs a truck cap. I would think a cap would help with the wind hitting the front of the trailer, helping with MPG'S. I have a tonneau cover now but was wondering if there was any benefit in changing to a truck cap.
Thanks Again

[KingFisher]

Originally Posted by tbrew100

Thanks for all the feedback, my original question was if anyone had experience with having a tonneau cover vs a truck cap. I would think a cap would help with the wind hitting the front of the trailer, helping with MPG'S. I have a tonneau cover now but was wondering if there was any benefit in changing to a truck cap.
Thanks Again

I don't think so, not where mpg's are concerned. I've had both. I also watched my mileage with the bed naked before I got them.

2008 silverado cc 4x4 5.3 with hard fiberglass tonneau
2013 silverado cc 4x4 5.3 with fold up tonneau
2015 silverado double cab 4x4 with shell

Not much difference in any of them. For one thing the shell weighs a lot more.

[tbrew100]

Thanks for the info!

[djeirlessr]

I never gave much thought to MPG. I guess because for 28 years I owned a boat. You go by gallons per hour. I've been asked how many gallons does my boat use per hour. I alway told them the truth that I didn't really know. If I couldn't afford to put gas in I would sell it.

My last boat was a 38 footer with twin 454 engines that loved gas. I did at one time out of curiosity check my fuel per hour. Going cruising speed, around 21 or 22 miles an hour it used 27 to 30 gallons an hour and I figured that was about .9 MPG. When gas on the water went up to $4 a gallon I quit cruising. I sold it last year and my DW and I bought our very first FW. Towing my FW I know I am getting better than .9 MPG cruising 60-61 MPH and the gas is not $4 a gallon.

If I can't afford the gas I'll sell the RV and stay home. I don't think that will happen because we enjoy it so much. Glamping is so much cheaper than boating.


Duane & Jan
2016 Crusader 295RST FW
2011 Toyota Tundra iForce 5.7 Limited Double Cab 6 speed automatic 4.10 gears

[bitNine]

It really depends on the truck. Most trucks these days are designed such that a tonneau cover will help mileage, but running with the tailgate down will make it worse. They are designed such that a vortex is created by the bed, thus pushing air flowing over the cap, up and over the tailgate. With the tailgate down, the vortex isn't created, and it changes the airflow. A tonneau will help the mileage because creation of a vortex is also creation of drag, but because the vortex helps reduce drag elsewhere, it's a net decrease in overall drag. So if you don't create the vortex, it's not creating drag, and the air coming over the cab and still flow much like it would if the vortex were there.

As for toppers, they also disrupt the flow of air coming over the cab. If they are taller than the cab, that makes it worse. They add drag and weight, so they are usually worse than nothing at all.

[lbrjet]

Slowing down and/or traveling on calm days yield the best towing mileage.


2010 F250 5.4L 3.73
2011 Flagstaff 831FKBSS
Equal-i-zer 4pt 12K

[ryand]

I remember a episode of Mythbuster's on Discovery that tested this and as it turns out the best configuration for a Pickup is nothing at all at least for MPG's. Tailgate up, no cover or cap.

[timfromma]

Originally Posted by ryand

I remember a episode of Mythbuster's on Discovery that tested this and as it turns out the best configuration for a Pickup is nothing at all at least for MPG's. Tailgate up, no cover or cap.

I remember that episode. They only tested tailgate up or down. They didn't test caps or covers.

[elind]

I towed a 38' Wildcat FW and a 6x10 cargo trailer cross country. I was surprised that the FW at 3 times the weight did 10.5 mpg vs 13.5mpg on the cargo trailer with a DuraMax diesel. I expected the trailer to get 15-16 but the flat front held it back like a barn door pull thru air. So if you had a boxy flat RV, a cap could help the air flow past it. But if you had a V-style TT the air should cut thru it with just a tonneau cover.

[KingFisher]

We need a nascar engineer here to explain aerodynamics to us.

I saw something interesting a few weeks ago coming home from St. Louis on the interstate.

There were some road construction signs on the left side of the road and they were mounted on springs. A semi tractor trailer passed me, since I'm apparently the only driver who obeys road construction speed limits.

As the truck sped by these signs they never moved. When he got about 100 ft past them they laid down flat and then popped back up. I saw it happen with 5 signs in a row.

[timfromma]

Originally Posted by KingFisher

We need a nascar engineer here to explain aerodynamics to us.

I saw something interesting a few weeks ago coming home from St. Louis on the interstate.

There were some road construction signs on the left side of the road and they were mounted on springs. A semi tractor trailer passed me, since I'm apparently the only driver who obeys road construction speed limits.

As the truck sped by these signs they never moved. When he got about 100 ft past them they laid down flat and then popped back up. I saw it happen with 5 signs in a row.

Shmucks like that are a big reason as to why I added a sway bar to my hitch.

[Too Tall]

Those wind deflectors like you see on the 18 wheelers seems like that would be helpful in increasing MPG. Anything to deflect over that 8 x 10 wall we drag around.