Gas Mileage: Cap or Tonneau

[user 64117]

I currently have a cap on my 01 ST. I have 64k on it now. I bought it used so I dont know when the last maintenance was done. I currently get about 12-14mpg driving to and from work which is 1/3 highway and 2/3 city (20-30 mph) for 20 miles total a day.



My question is:

Does a cap hinder wind resistance more to lower mpg vs a Tonneau? I am debating on getting a tonneau just for the looks of it.



I am also considering whether to buy a tonneau or do performance mods like k&n, exhaust or XCal2?



Whats your opinion? I value everyones opinion on this site cuz you guys are "truck guys" and have worked on your own trucks with great results.



thanks in advance

DanG

 

[FlipTrac_511]

I have an A.R.E. LSII tonneau and I did not notice any increase or decrease in mpg. Sometimes I wonder if its weight is neutralizing any aerodynamic benefits and vise-versa (a cap would even be heavier I imagine).



I also have a Volant intake and Flowmaster exhaust and used an XCal regular octane performance tune. I used to drive about 35/65% city/highway and was averaging about 17mpg. I should also mention that I may be on the aggressive side during green light acceleration.



But the tonneau succeeds in its purpose of securing cargo storage. Although its weight and size discourages it, I can remove it if I need to haul tall cargo. And finally, it does add a different look to the Trac, so if you're getting one for the looks as you state above, the A.R.E. tonneau is for you Dan.

 

[Ryan betts]

it depends on how the cap fits on the truck. i have heard that tonneau covers improve gas mpg. i would do the performance mods first though. i'd get exhaust, shocks, then the programmer!

 

[Ryan Schaecher]

I picked up ~2-3 MPG with my tonneau (that's based on miles per tank so take it as it is).

 

[Fudged Undies]

For gas mileage, you're better off with a tonnea. Though I don't thing the aerodynamics will matter much, noticed zero difference when I added my tonnea, I think the weight difference between the two will/would make a bigger difference. Will still be nominal but the tonnea would probably be better.

 

[Casey B]

I get better gas mileage without a cover at all. Maybe it's the slightly lighter weight I don't know. Driving habits play a big part.

 

[Todd Z]

I noticed no gain from my tonneau to my are cap...

Todd Z

 

[TomT]

There was a study by a university not to long ago about covers and the old myth of removing the tailgate to save mpg on pickups. None made any difference.

 

[user 64117]

ok. then my dilema is just based on getting the tonneau due to looks vs. performance mods.



thanks for all the feedback.

DanG

 

[blert]

There was a study by a university not to long ago about covers and the old myth of removing the tailgate to save mpg on pickups. None made any difference.

Very true. No cap, tonneau, mesh "tailgate", or driving with tailgate down will gain you any MPG what-so-ever. It is an "old wive's tail" (so to speak).

 

[Richard L]

There is absolutely no difference in gas mileage on my two Sport Tracs with and without the tonneau cover.



The study was also checked out on Myth Busters and found that lowering the tailgate actually reduced gas mileage. During normal driving, the air would form a bubble in the pickup bed and all the air flowing over the cab would be directed over the tail gate. When the tailgate was lowered, the air bubble would not form and the air going over the cab would create turbulance in the bed and reduce the gas mileage.



I don't know that a cap would give any better mileage, and it could even hurt it some.



...Rich