Camper shell mpg drop?

[sportcoupe]

I have read some owners that install a camper shell report a 2 mpg loss in mileage? Can anyone with a camper shell (aka truck cap, topper, etc....) report their mpg losses if any?

 

[warbat]

When I had my 2011 qc 4wd with the 4.7 I probably lost close to 2mpg when i put a fiberglass cap on it.

 

[69GWC]

My mileage did not change any.
It does ad weight so I could see that happening but I would not think 2mpg that seems pretty high.

 

[TRCM]

it does change the aerodynamics, and will add drag....that alone can drop mpg pretty good.

Those big towing mirrors are good for 1/2 - 1 mpg drop by themelves

 

[zrfraser]

These trucks are sensitive to any aerodynamic change. I was hauling some pallets home the other night and had one slightly higher than the cab and there was a noticeable change in performance and MPG.

 

[Joes1500]

I didn't see any noticeable change after mine was put on.

 

[BWL]

I didn't see any noticeable change after mine was put on.

View attachment 115949

I wonder if that has to do with the air suspension maintaining the rake.

 

[Joes1500]

I wonder if that has to do with the air suspension maintaining the rake.

I don't have the air ride !

 

[BWL]

I don't have the air ride !

There goes that theory.

 

[Joes1500]

I drive the I-35 a lot. Before the cap I was getting about 16.5 -17 mpg at 75-80 mph. After getting the the cap , I'm still seeing the same. Depending on wind and traffic. This is from the computer not hand figured.

But, either way I didn't see a noticeable difference.

What I did notice after getting the cap, and I think this is mainly from always having 2500 and 3500s is that it really exaggerated the amount of body roll and wind push.

I will probably be looking into some after market sway bars to cure that.

 

[69GWC]

Hellwig will make a huge difference, so glad I boight it.

 

[aladin_sane]

I didn't notice any change when I added my topper.

 

[CostaRam]

As far the camper shell is not higher than the cabin there should not be a noticable lower mpg.
Chris

 

[sportcoupe]

Lots of replies in just a day. Thanks.

I am looking at a shell 5" higher then the cab for more headroom. I haven't ordered it yet, going today to order.

Never thought of more body roll and wind buffeting. I hope my air suspension will maintain it's excellent body roll as it is now. Stock I have almost no perceivable body roll.

Thinking of adding a bedrug also over the factory spray in liner.

 

[CostaRam]

A fiberglass camper shell is not really heavy and should not induct considrable body roll.
However the 5 inch higher roof will most likely make your mpg worse and you will loose precious loading weight.
Chris

 

[69GWC]

lol, guess heavy is relative on this one.

I bet mines gotta be around 400lbs.

 

[CostaRam]

I bet mines gotta be around 400lbs.

OMG!
I have a Isuzu D-Max /Chevrotel Colorado with a topper and it weights not more than 100 lbs.
A Ram is considerable bigger but i did not guessed that it's so heavy.
400 lbs is more than 1/3 of the allowable load, so people and gear can be not more than approx 700 lbs.
Chris

 

[aladin_sane]

I agree, the topper being higher than cab height will cost you some mpg. I doubt my leer cab height topper weighs any more than 200 lbs.

 

[avantiguy]

While I don't calculate my mpg often I do keep an eye on the EVIC mileage display and I didn't see any significant change in average mpg nor steady mpg at 72 mph on cruise. I'd guess cap design like the square back aluminum ones might have more effect than the smoothly contoured fiberglass ones.

Mine's a Z-series ARE cap.

 

[sandawilliams]

Lots of replies in just a day. Thanks.

I am looking at a shell 5" higher then the cab for more headroom. I haven't ordered it yet, going today to order.

Never thought of more body roll and wind buffeting. I hope my air suspension will maintain it's excellent body roll as it is now. Stock I have almost no perceivable body roll.

Thinking of adding a bedrug also over the factory spray in liner.

Even without additional wind resistance the added weight will have some effect on mileage.