Roof mounted air dams..

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Well-known member
Sep 26, 2005
Cannot find any concensus so I will ask you folks ...? :)

I drive a Ram with the magmum engine..the box is loaded with MX bike, 45 gal of water and sprayer, assorted accessories, bicycles, and a 4000 watt generator.  I will be towing a 25 foot shamrock. I usually Cruise at 105 Kms..just above 60mph.

Is an air deflector worth the 300 dollars it is going to cost me ?


Personal opinion, I doubt it. With what you will be carrying in the bed, it will already pretty much breakup the vacuum in the box before it even gets to the trailer. I used to have was a 22' Winnebago Chieftain, and it actually got better milage when I had a toad behind it .. no air dams or anything .. as the toad broke the vacuum created by the rolling breadbox. I'm sure that there will be a lot of disagreement on this one, but like I said, my personal opinion

Generally no. While air flow can make quite a difference in fuel economy, there is no generic solution that improves air flow over a truck - or truck and trailer - to any noticeable degree.  It might even hinder the airflow in a few cases.  Design engineers spend hundreds of hours in wind tunnels figuring out just how the air flows over a particular surface and how to adjust it for maximum efficiency. You would have to do the same for your truck, loaded as it usually is loaded when traveling with the trailer atatched.

Save the $300 to buy fuel.
I agree with Gary again on this one.  It takes a lot more to effectively control airflow to make any positive difference in fuel mileage and without wind tunnel test on YOUR truck and trailer as you have them configured will most likely provide a negative result.  Like Gary said save your money for fuel.

Thanks folks,

Was at a RV show this weekend ...asked this question to love that"deer in headlight" look...

No air dam for us.


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