All the him-hawwing about the air damn is just goofy IMHO.
Do it and try it or don't and move on.
How many here care about how their 4x4 truck (on stock tires) handles on a race track?
This isnt a formula 1 car where we are trying to pickup an extra 10th, its a 4x4 pickup truck for cripes sakes. It ALREADY handles squirly on the highway at 80+ mph......what do you expect? Its a high height, high profile vehicle with marginal tires and squishy suspension. How many race cars match THAT description?
These particular air dams are not for handling purposes.....go under there and move it around and you will see how flimsy it is. It is there simply for aerodynamics to improve on the drag enough to add .1 mpg onto the gas mileage and to (in someone's eyes) smooth out the front end for aesthetics, like on a minivan.
REAL air dams made for handling purposes are MUCH lower, hug the ground, are much more rigid and prevent air from getting under the vehicle. This air dam is simply to SMOOTH the air out somewhat lower drag.......the truck STILL (with the dam) sits high and will get plenty of air under it, and that is at STOCK height and rake. Not to mention that we change the aerodynamics ourselves when we add lifts, light bars, bully bars, side steps, etc etc etc.
Consider that if you lift the truck "properly" , you drop the suspension......thereby creating drag etc etc under the truck that wasn't there anyways with the suspension parts now being "exposed" below the horizon of the undercarriage...all those bits poking down affect drag. So lifting the truck will likely cause the same "issues" as removing the front plastic.
Next, consider that the front bumper ALREADY extends very low compared to truck bumpers of old. (Too low IMHO). The approach angle on this truck with this bumper and the air dam isnt much better than a crossover SUV. But the lower bumper helps with silencing the safety whiners and improve aerodynamics slightly. In the old days, you had a bumper that was maybe 6 inches high and that was it.....the front end was open and lots of space below it. How did we survive without plastic doohickeys hanging from the front ends back then I wonder? Those trucks could do 80 and be just fine, and that was with older technology tires and crappy suspensions.
Finally, on a 4x4 truck that is going to see off-road, ramming the plastic against rocks or snow-plowing sand, snow and dirt does way more to lower the efficiency of forward motion and add resistance than REMOVING it will.
Ok, so the other options:
1- Cranking up t-bars on a vehicle that has them is easy....but affects alignment and possibly warranty. Will only buy you an inch or two tops and will stiffen ride. Been there done that.
2- Adding a leveling kit will leave the ride alone since it in effect drops the front suspension and raises the front end only, but will affect alignment and affect warranty unless you have a dealer that will work with you. And its extra $$. Plus, the rear will now droop when you tow. Adding air bags will fix that, but of course more $$$.
3- A real suspension lift is cool and is what I would love to do, but is $$, will likely affect warranty coverage, unless you have a dealer who will work with you (get it in writing). Add to that the wear and tear of extra large tires on the whole system not to mention their cost and having no spare.
Finally, 1-3 , if done to a lease vehicle, which many of us have, have to be reversed if/when you return the vehicle. 1 is easy, 2 and 3 not so much.
Look -- Everything we do to our vehicles is a trade off compared to the stock design. That is how it goes.
I am willing to give up a minsicule amount of MPG for the ability to go through sand ruts on the beach without bashing the cheesy air damn off the sand constantly.
I am willing to bet that the affect that this air diverter has on handling at speed is the same as one of those cheesy air-wings that the kids add to their souped up 4 door rice burners.....not much if any in practical situations. In the air tunnel? Maybe.
But hey.....Its a free "mod", can be done in 15 minutes and makes the truck look better (IMHO).
If I find that the truck is out of control on the highway at 80 mph, I can easily put the air dam back on in 15 minutes.
I have a feeling though, the air dam will be residing in my shed for a long time.
But....To each his own....and YMMV.