improving aerodynamics w/ 5er

[wjpatton]

I'm looking for suggestions to reduce aero drag on 07. 5 dually with 30' fifth wheel. At present, I'm planning on extending the stock front air dam an additional 3 inches with a sheet metal extension. Also, what about some type of bed cover that keeps air out of the bed while towing? Anyone using AirTabs to reduce turbulent air off the 5th wheel? Thanks!





Mr. Bill

2007. 5 3500 dually 6auto

 

[tempforce]

i'm installing air tabs on the top of my cab and at the back of my trailers.

the lower air dam will make a difference, but watch for low clearance. my factory air dam already touches some parking stops. lowering the rear of the truck, and using a bed cover will help some as well. if your really serious, sheet metal, use plastic or fiberglass sheets on the underside of your truck. like a air stream trailer.

cc

 

[CUMMINZ]

I am in the process of designing and building an idiot rack for the truck bed to protect my rear glass as well as mounting a wing for aero-dynamics. For my short low speed camping trips I don't think will help much but when I make interstate trips I think will help a lot.

 

[GAmes]

Before you spend your hard earned money on a wing, see if you can find one mounted to the top of a pick-up towing a 5er. You will see that it is not close enough to the 5er, not wide enough and not tall enough to actually aid in aerodynamics. Air does not keep propelling upward after going up the face of a wing, it goes straight back into the front cap of the trailer. It will, for the most part, keep bugs from hitting the small portion of the front cap that it covers. That will be it's only advantage. Also consider this, when the wing is pushing air up it is pushing the cab down, effectively making your truck heavier and possibly caving in the roof. No gain there. The high pressure on the front of the wing will create a low pressure area behind it, so now you are overcoming suction. No gain there. The most effective way to cut down on drag is to slow down. With my timing and cam my best RPM for fuel mileage is 1900. Any less while towing my 5er makes the engine lug. Your best RPM may be as low as 1700.



FWIW, I pulled an enclosed cargo trailer from San Diego to Ft. Worth, then to Baton Rouge and then to Phoenix. It had air tabs on it and the mileage I got while pulling it was no better than similar cargo trailers without air tabs. If there would be any improvement I believe it would be a heck of a long time to recoup the cost of them.

 

[Andersonville]

What he said up there!!

 

[DMcGalliard]

Wing comment

I had wing with my 98. 5 and fifth wheel and tested on a 10k trip. I tried it in all configuration and could find no improved mpg. In some situations the mpg went down. So it is in the shed now. Most fifth wheel now have improved nose designs that help with the drag. I think that wing helps with a tagalong as the air lift is about the height of the trailer. With the fifth the nose does the lift and with the wing there is drag behind the wing. Just my two cents worth, would not have one. On my current fifth I have pulled it 50K.



Dave Mc