According to mythbuster, your mileage will be better without it, but I noticed no difference at all in milage, when I put mine on.

 

The Tonneau Cover Fuel Economy MYTH

The Tonneau Cover Fuel Economy MYTH | Tundra Headquarters

 

Well I guess I must be one of those they feel sorry for
in the 8 months I have had my 2004 Canyon I've put over 23,000 miles on it dumping nearly
$4000 in the gas tank

with the cover on
At highway speeds (70+mph) i see around a 1.43mpg increase
In the City, when stuck in traffic or just driving at slower speeds their is no noticeable difference in MPG

However when Driving sensibly and using Cruse Control I can increase my millage
by about 3 mpg with the cover on, highway (70+mph)
by about 1.81 mpg with a open empty bed, Highway (70+mph)
by about 0.73 mpg with the cover on, (40-50 mph)
by about 0.50 mpg with a open empty bed (40-50 mph)

Bottom line is if you drive sensible you will get better mpg than if you by a tonneau cover
Oh and I bought my Extang Solid Fold to keep items in the bed Dry and Secure not for the mpg savings

 

Mine has not changed my fuel mileage. But, it does look a lot nicer than that scratched up bed!

 

i have an undercover and i see no change, but a locking cover is very nice to have in a big city thats about it

 

Damn, you think it would at least have some affect....

 

I have actually notice the differnece in gas mileage from when i had one to now without one. It made enough to where i notice the difference

 

Haven't noticed anything, but I didn't buy it for that reason anyways.

I recall seeing somewhere (mythbusters maybe?) that manufacturers design these things to basically create a small pressure pocket when at speed in the bed, the air passes over the bed and doesn't drag against the tailgate.

Also for that Tundra article, the added weight of the cover is going to nullify the fuel savings even more.

 

U dont get a cover to save gas u get a cover to COVER your stuff.

 

I did not notice any difference in fuel mileage but it did drive a little smother at high speed for sure.

 

I did notice a improvement in gas milage with my cover (~0.5-1mpg). Also noticed less noise on the highway with the cover.

 

I made a 8 hour trip with out my tonneau cover and used 2 tanks of fuel.
I installed my tonneau cover and made the EXACT same trip on 1 2/3 tanks. Now keep in mind I was considering this on my trips, keep same speeds, same route. I beleive it made difference in about 10% in fuel millage, the company claims 13%.
I bought my access tonneau cover from zigsauto.com for about $350, I would do the same before making my own. Hope that helps

 

You also have to factor in the environment, wind can play a big role in fuel economy, as well as temperature and humidity. Quality of the fuel as well.

 

I had a professor actually discuss the aerodynamics of an open truck bed in an aerodynamics class I had, it was pretty cool.

 

When I had my fiberglass tonneau, If I gained any MPG in aerodynamics, I lost it with the extra weight :shrug:

 

In all I have not seen any big noticeable change in mug's. I would still get one though. I use mine to lock up stuff in the bed when I need to make other stops when I am on errands. Now I do agree that it strewn lines the look. But don't buy on for mileage, buy one for what you will use it for.

 

I built mine using the general principles of the how to, kept the cost at 60-70 dollars and kept up with the mpg. Most fill ups since making it have seen a .5-1.5 increase. At a weight of 25 lbs including mounting hardware, I am happy I did it. On the flip side of the coin though, I built it for added bed security.


Sent from my Autoguide iPhone app

 

I noticed on my first 2 colorados with the I5 that I got beter mpg by about .5-1 mpg but I can't say for the new v8 truck because I had the bed cover on an hour after I picked the truck up from the dealer also my bed cover is very very light might be 5 lbs I have the extang full tilt