Tonneau covers really Save gas?

I haven't noticed any increase in MPG's.

 

Nascar probably uses them more for down force than to reduce drag. The ass of any truck is light as hell compared to the nose.

 

covers really only increase mpg if it is very blustery out

when extremely windy, the wind can force the vortex bubble to collapse
and wind pushes around in the bed, slowing you a bit

when very windy like this, a cover can increase mpg, but that is it

in most driving, an empty bed with tailgate up is best overall mpg

been proven in wind tunnels with smoke and mythbusters tested. no real
gains either way. you haz a truck, it will get XYZ mileage, and best
with empty bed and tailgate up

 

It's not doing much if anything for my lifted regular cab.

I love that in this thread different folks are claiming different results from the mythbusters test.

As near as I can tell, they only tested two configurations - gate open, and gate closed.

http://dsc.discovery.com/tv-shows/m...atabase/driving-tailgate-fuel-consumption.htm

 

It's going to vary from vehicle to vehicle as well as condition to condition.

If a truck has over a 7 ft bed like my old Silverado I bet you'll see more benefit than one with a 5 ft bed, different design and shape of trucks, different weather conditions on the highway, whatever. The point being, you can't just say yes it does or no it doesn't work across the board. Perhaps if a few people have very similar trucks in similar conditions we're on to helping some (which we do to an extent here) but the reason people's experiences vary are because there are variables . . .

 

Chevy also did this for the Silverado. They made the front fenders closer to the cab than previous models to help with fuel economy.

 

My experience differed from mythbusters. I was measuring my mpg religously prior to picking up a tonneau cover. Once installed, there was a noticeable increase in mpg. Why a difference? I couldn't tell you - like someone else mentioned, perhaps it was the difference in truck and/or bed sizes, designs, etc.

 

my fuel economy increased with my tonneau. and there's a reason why the Ram 1500 with the advertised 18/25 MPG, the HFE model, comes standard with a tonneau and the other models don't, and get 17/25. So maybe minimal, but it does have some impact.

It can also differ by what kind of tonneau. If you're adding a hard folding one, they weigh a significant amount that can impact fuel economy as well, probably off-setting the gains from aerodynamics.