I do believe it is helping. One thing for those that have inserted 'city' driving into their posts. I live in a somewhat rual area ahd have to drive 26 miles one way to and from work. Most of that driving is at 50-65mph. There are some lights and on occassion some stop and go driving, but if I just go by my average MPG's at the end of a tank, I believe that I've picked up some MPG. I reset my MPG rating indicator at each fill up.
It can be a difficult thing to pin down. On a recent tank of gas I did a lot of short trips and found that it shot my average MPG to heck. Way down from average (with Toneau installed). So you have to drive the same each time, and enough of it has to be at high enough speeds for long enough to help. To short of a commute or a commute with too many stop lights or with not enough higher speeds and you'll never get anything out of your toneau cover on increased MPG's.
My average MPG's per 3/4ths tank before was at 16.4. Now it's at 17.2 (ish).
Larry
Well, you are proving it.
Short trips, where the speed isn't enough to utilize the possible aerodynamic benefit, you are payig for the extra weight.
Longer trips, were the supposed aerodynamic benefit comes into play, you are getting better.
Now, the proof is in the pudding....is the decrease in your 'city driving' less than the 'increase' in your non-city driving ???
If yes, then you gained, if not, well.......
Most people, when they do a mod that someone tells them will increase mpg for a certain driving style (like gears), they say why yes, it does, I get an extra 1 mpg driving around town. They fail to tell you, they get 1 mpg less on the highway.
So, is it really a benefit ? it all depends on how much drivign you do in the city vs on the highway.
Or bigger tires on a truck...yeah, highway mpg goes up some but city mpg drops a lot.
