Okay so I had this really fugly old topper on the back of my truck, as seen here:


Well, now I took the topper off and my truck looks a lot better I think:


But, I am wondering. Which gets better gas mileage, topper on or topper off? My father keeps insisting me that having it on gets more MPG (less drag) but I think having it off gets more MPG because it's less space for the truck to exist in and keep with it.

So which is right?

 

That depends.

Who's buying the gas?

 

Me of course, I bought it from him since he was going to be taking it to the junkyard this fall (or so he said.)

So I take it he's right?

 

He would have been right because

A) He's your daddy and
B) He's buying the gas.

Since you are buying the gas, he's right because

A) He's your daddy.

I think you should leave it off because

A) The truck looks better
B) You prefer it off
C) It's your truck
D) You buy the gas

The two important things to remember are:

A) There's a mpg difference one way or the other but, it's miniscule
B) He's your daddy

 

Well the way he was talking, it sounded like I was going to be losing like one or two MPG's just for taking it off, which was sort of hard to believe just for an optional truck-accessory - a topper.

 

It lessens the drag from an open bed but adds some weight. I would imagine those two conflicting factors just about make any mileage advantages either way a wash, though I have no solid data to back this up. Decide based on whether you need it and whether you like the looks of it. Personally, I had an old style white aluminum contractor's cap on my old Ranger from when I was in college, saw it while passing by a cap dealer, and decided to pick it up since it was cheap and functional. My mother and aunts, who normally really could care less about truck accessories, made fun of it and said I should have spent the money on a better looking aluminum one or just not had anything at all.

 

On the show Mythbusters they did a test to see whether a truck gets better mileage with tailgate up or down. The truck gets a vortex going which just pushes the air over the tailgate when its up so the drag is actually less (i think) with an open bed where the air touches really nothing to a topper where it drags all along the top. But the point is it is a minute difference if any and just do whatever looks best.