The ground effects (currently known as air dams) really start to kick in over 112 mph. Thanks for testing the theory!!!

 

Air dams in some designs are a important part of the cooling package, i doubt this is the case with SD but i would be cautious in removing these especially if you work the truck.

 

CORRECT:
The air dam diverts the air which would normally flow underneath the vehicle. This creates a void behind the air dam thus causing a vacuum rather than a pressure situation. The air through the radiator rushes down to fill that vacuum and hence the increased flow through the radiator opposed to having the a rush of air under the vehicle trying to escape upwards. In racing cars that vacuum also helps to hold the car down on the road, an effect which would not be noticeable on a truck. The same can be said for a negative rake (rear end higher than the front) in that the ever increasing space as the air travels toward the back at speed also increases vacuum and hold the rear end tighter to the pavement.

This can be seen in the stickers on the door jambs. Ford has interpreted the gps and electronic toll readings of the customers and assigned corrected axle weights for each customer's truck. The axle ratings are reflective of the driving habits already demonstrated through electronic surveillance.

 

Well if you are worried about $74 every 10,000 miles then you better roll up all your windows and only drive around with a half tank or less of fuel.

 

Couldn't it be a tad smaller and do "almost" the same job??....lol. It does stick down pretty far. The old one didn't stick down that far on the 250/350 and it seemed to work. Now...if it can give me 3 or 4 more mpg......it's looking better every second !!

 

I'm sure Ford has done hundreds of hours of wind tunnel testing to get the best compromise of size/MPG/cooling benefits.

 

That's funny! My ecoboost truck won't go that fast, she tops out at 95 or so. I definitely noticed a difference when I took it off, maybe I was anticipating a difference, IDK.

 

It also keeps air directed under the vehicle, so salty dirty air doesn't get hung up on under hood lower components for reduced corrosion.

 

One solution is to get the 2wd airdam.
I'm not sure about the 2017, but up until this year the 2wd dam is nearly 2" shorter and tucks up a little nicer to the bumper. I've always bought and installed them on my trucks.
Keeps things neat and clean.

 

I thought the tall 4x4 air dam is Fords complimentary snow plow?

 

I must be the odd one. I don't mind the look of it.

 

Have you considered backing in so you damage the air damn?

 

You could heat it gently with a heat gun. It should have a memory and easily be formed back to original shape/

 

I agree and it is an option to try that will cost you nothinng.

 

i highly doubt removing it will cause any tangible effects, i.e. decreased cooling, noticeable reduction in fuel mileage, etc...

I removed the one on my GMC and have not noticed any difference.

Is the dam easily removable? is there anything behind there hanging down or will it clean from the bottom of the bumper?