|
The bottom line is it depends on the truck. How the air back fills behind the cab varies across makes and models due to a plethora of differences - some negligible (style), some substantial (shape). On my xCab Tundra 4WD a hard tonneau was an improvement with highway 22 mpg. With open bed 20-21 mpg.
In general, I doubt it can be worse than open bed, and don't see how it could be worse than flat tonneau either. But my opinion is moot. Ask your truck. Testing a cheap prototype was an excellent suggestion!
Cheers
KB
|