Let me first say that I don't think it will make much difference one way or another. Has anyone made a couple of runs with the cover, and taken it off, and seen a difference? I bought a Covermaster that has a small lip on the back, not really a spoiler. Not sure about the weight, maybe 75-100 lbs. The weight will slow my truck down, but it has to be more aerodynamic. I'm sure the faster your truck is the more aerodynamics affects performance. I'm going to get Granny to tune my truck this spring, and see how quick a basicaly stock RCSB can go. Tonneau on, or off?

Bruce

 

i would say 1/10th or 2/10th at the most.... maybe it wont be any difference.... i have a tonneau cover but I have always ran it with it on so I wouldn't be able to tell you the diff.

 

i think it wouldnt make 5 one hundredth of a second. it is purely the weight of the cover. nothing to do with wind resistence at your spead.

 

I dont notice much with my filberglass one.

 

I would like to know as well, I have a fiberglass cover.

 

It also depends on which one you have. I take mine off due to the weight.

 

You would think that it would just about even out, more wieght but less drag. I may have to make a few runs with and without it on the 12th and see what the difference in times is.

 

There is one thing these trucks would not suffer from....Weight over the rear tires will impove 60 foot times, there for improving 1/4 mile times.

 

That is true too.

 

My S10 runs the same with the cover on as it does with the cover off and the tail gate removed. With the gate on/closed and the cover off I lose 3/10ths consistantly.