I noticed a new Dodge 2006 1500 with a small air deflector on the tailgate yesterday. I'd assume that it is to improve aerodynamics. Any idea as to how much it improves the Coefficient Drag??

I thought it looked kind of cool and would only further throw off those who are trying to figure out what my degbagged truck really is. Those who know their trucks really take a hard look already.

Rick

 

a little OT my debadged truck gets lots of looks, and since i added the h2 wheels people have said "i didnt know hummer made a truck"...

 

Imagine the LEO that pulls over a "big white truck" in my case.

I'm actually looking to find out if this is of any measurable benefit if I were running empty. Without trailer.

Nothing on my truck does not give more comfort, better mileage, more HP, lower temperatures, add protection, or delete excess weight. My truck is all go and no show! I aim to keep it that way.

FYI Hummer makes a truck now! Just not with a Cummins

Rick

 

In general a spoiler will only add benefit at higher speeds. Off the top of my head I think it was 100+ mph to show an added bonus. Porsche has the wing come out at 65mpg and up. I would think a hard cover plus a spoiler would be the best setup. In college we did a wind tunnel test on drafting to prove that you have to be extremely close and traveling at over 100mph to make it work. The wing or spoiler on the back is the same thing. It is all a function of speed. More speed more down force.

John

 

In this instance you wouldn't want the spoiler, or "wing" to provide downforce.

Mileage gains can be realized if the aerodynamic device can improve the laminar airflow over the vehicles exterior; less turbulence and airflow separation = less aerodynamic drag which outweighs the slight increase of parasitic drag common to these items.

Benefits can be realized at legal speeds.

 

XLR8R,

Exactly my point given that the coefficient drag rating of my truck is much like a brick every little bit helps!!

Thejoker502, Yes my truck is approaching the 100mph mark in the quarter mile

I was just wondering if any of the engineer types here could answer my question as to how much help it would really be??

Point being if I can pick one up on the cheap then I may just do it!

Rick

 

Well - it probably won't hurt your mileage!

 

Rick , I read not long ago that you can gain more by cleaning up the airflow underneath the vehicle. take a look at the latest Ferrari and Benz , the underside and rear exit have been cleaned up with a smooth exit flow. and no spoiler hanging out.

 

JohnCa58,

That is already in the works bud! I could use some help though I'm going to change to 12 50x33 R 17s in late October and I'm NOT looking for lift just handeling. Wherever I can put a ground effects system I will.

I still think the little tailgate air deflector is cool!! LOL!

Rick

 

They actually help a fair amount. Chevy (GM) was the first to "find" this on their trucks, and if you notice they've had that lip on their trucks since. The story I heard on that was it was a functional tailgate lip protector first, but they found that having the top edge protruding back made a fairly significant improvement in drag, and thus mileage, in the wind tunnel. Major gains, no, but every little bit helps.