Improve gas mileage while towing?
 

I was getting 9 mpg while towing a 20' enclosed trailer. My truck normally gets around 18 mpg.

Has anybody done a comparison with flat nose and V nosed trailers? Is it worth constructing a V nose on my existing trailer?

Would a truck cap help? Maybe reduce the turbulence and help the air flow above the trailer?

Any other suggestions?

Thanks,
BK

How fast are you driving?

Usually around 70 mph.

I guess I could drive slower. That would be a free improvement.

That is why I asked the experts!

Slow it down 5mph and get a wind spoiler on the roof of the truck cab or cap if it has one....wind is a bad thing.

Does one of those bubbles on the front of the trailer help?

A truck topper would help to allow the wind to flow over the truck and trailer as one. I found a big difference when towing my car on an open trailer before and after I had a topper installed on my truck bed. The top of the truck was even with the top of the topper.

I think the bubble is the best design. If the truck had the shell (topper) and the nose of the trailer was domed, that's got to help.

However, on one episode of "Mythbusters" they studied tailgating. I think of a trailer as the same as the car they used behind a big truck while measuring mileage at various distances from 20 feet to just about touching. At just about touching, they got some improvement. The rest was nominal.

But nothing will beat going slower. Air up those tires too.

I always noticed a huge difference when towing my open car trailer with the tire rack filled with wheels/tires. Seemed to drop the MPGs greatly.

Air is thicker than most people seem to believe. --Just think, 90,000 lbs of jet will hang in the air, supported with just a couple 100mph's fwd speed around it's wing.

read: speed makes for some huge forces - slow down.

Most 8x24 box trailers are taller than a standard Pick up truck. so the topper shell would have to be the kind that ramps up taler at the back. Still the upper front of the trailer will be pushing a lot of wind. Could you modify the front of the trailer to slope it down at least 18"

look up the aero vault trailer.

or get a Diesel truck.

Ok, I just did the math.

How many miles would I have to drive to break even on a $1500 topper if I save 3 mpg with gas at $3.75 per gallon?

15ooo miles!!

So... does the topper help or hurt gas mileage when not towing a trailer?
If it helps, a topper sounds great.
If it hurts, I dont think its worth it.

I get the same mileage towing my 22ft ATC. Drop to 60 and mileage went up 3mpg...

I tried a spoiler mounted on my roof rack with marginal improvement (call it .5 mpg) which I would chuck to weather or other non related variables (I did not do a scientifically controlled test).

Use a bed cover. Very practical and you might gain some mpg.

If you do this only so often, the payback time is too long.

Home-made Chin Spoiler, good for 2-3 mpg on the hwy.
http://forums.pelicanparts.com/off-topic-discussions/465923-chin-spolier-fast-easy-cheap-effective.html
http://i184.photobucket.com/albums/x...20Up/CHIN7.jpg

I saw these on a Transvan once, don't know if they work.

http://airtab.com/main.html
http://airtab.com/images/white.jpg
http://airtab.com/large/ontruck.jpghttp://airtab.com/large/backtruck.jpg

Inflate tires. Sythentic fluids. New air cleaner. No rubbing brakes. Draft a large truck. That will push up the mileage. You might hit the truck ahead of you however.