Lower Air Dam

csheatz · October 8, 2008

Ok I took the lower air dam off yesterday. The one that has 2 10mm screws in the corners and snap things across the front, its about 3" tall. I think it looks a lot better without it, takes away the "soccer mom" look. I noticed in the manual it says it can be taken off for more ground clearance if needed, I will soon be blasting through snow banks and dont want to break it or be out there removing it in cold weather and break it due to cold plasic.

The question i have is am I effecting anything such as cooling, mpg's, or is this going to allow more road crap to eat away at the underbody?

Wingnut · October 8, 2008

I believe it's primary function is fuel economy.

Majorleaguebass · October 8, 2008

Downforce...you're gonna lose downforce and flip over backwards!!!!

I took mine off, i dont think it serves any purpose

csheatz · October 8, 2008

Downforce...you're gonna lose downforce and flip over backwards!!!!
I took mine off, i dont think it serves any purpose

COOL, cant wait for that! I will be sure to post pics!

66nova · October 8, 2008

Ok I took the lower air dam off yesterday. The one that has 2 10mm screws in the corners and snap things across the front, its about 3" tall. I think it looks a lot better without it, takes away the "soccer mom" look. I noticed in the manual it says it can be taken off for more ground clearance if needed, I will soon be blasting through snow banks and dont want to break it or be out there removing it in cold weather and break it due to cold plasic.

The question i have is am I effecting anything such as cooling, mpg's, or is this going to allow more road crap to eat away at the underbody?

I doubt you notice any difference. On a lot of older cars the air dam can have a lot of effect on cooling, so I might watch your temp, but I doubt you see any real differences.

chuck16 · October 8, 2008

I really don't think it makes any difference to Fuel Economy or anything. I suppose if anything it will increase your efficiency as your not moving that extra air around. I actually added one from an 05 Suburban to mine...

Majorleaguebass · October 8, 2008

If you dont take pics iam gonna kick you in the balls.....LOL!!!

05silvycrew · October 8, 2008

Ok I took the lower air dam off yesterday. The one that has 2 10mm screws in the corners and snap things across the front, its about 3" tall. I think it looks a lot better without it, takes away the "soccer mom" look. I noticed in the manual it says it can be taken off for more ground clearance if needed, I will soon be blasting through snow banks and dont want to break it or be out there removing it in cold weather and break it due to cold plasic.

The question i have is am I effecting anything such as cooling, mpg's, or is this going to allow more road crap to eat away at the underbody?

Fellow Mitten Dweller:

With winter coming on, I don't think you'll have to worry about cooling.

MPG's won't be affected at all.

It won't break off. I went nose first into a ditch with 3 ft of snow at 40 MPH...didn't even bother it.

I think I'll be taking mine off in a couple weeks. If you're worried and want to wait to see what my results are, I'll be more than willing to share.

Take care and stay safe out there, always watch out for the other guy/gal.

csheatz · October 8, 2008

Ok I took the lower air dam off yesterday. The one that has 2 10mm screws in the corners and snap things across the front, its about 3" tall. I think it looks a lot better without it, takes away the "soccer mom" look. I noticed in the manual it says it can be taken off for more ground clearance if needed, I will soon be blasting through snow banks and dont want to break it or be out there removing it in cold weather and break it due to cold plasic.

The question i have is am I effecting anything such as cooling, mpg's, or is this going to allow more road crap to eat away at the underbody?

Fellow Mitten Dweller:

With winter coming on, I don't think you'll have to worry about cooling.

MPG's won't be affected at all.

It won't break off. I went nose first into a ditch with 3 ft of snow at 40 MPH...didn't even bother it.

I think I'll be taking mine off in a couple weeks. If you're worried and want to wait to see what my results are, I'll be more than willing to share.

Take care and stay safe out there, always watch out for the other guy/gal.

Yea I tend to save the playful driving for when I go up north, I dont like doing it around the down state area, just to many poeple. But when I get on our property after a good snow there is no fear! I know whats under the snow, and its just me. besides if the unthinkable happens and i get stuck, i just use the plow or tractor to help me out. after play time is over we plow/ blow the snow out anyway so there is not even tracks left!

I am going to leave it off and watch the millage and temp for a while, i think all will be fine. I have a trip up north next weekend so that will be the best to get a reading on temp and mpg's. its about 260 miles one way.

5Alive · October 8, 2008

GM wrote that the lower airdam was added to improve fuel economy, by managing airflow under the vehicle. GM also closed off the center hole in the intermediate air dam of GMC trucks and SUVs in 2005, in addition to adding the lower airdam, for the same reason.

Someone above suggested that the airdam increases the frontal area, and therefore assumed that mpg's would be worse with it on. NOPE. Lower air dams, when properly shaped, reduce the co-efficient of drag, and control eddy currents under the vehicle. That's why race cars and race trucks have them. That's why the Prius and other high efficiency cars have them.

People who use their gas and brake pedal a lot (racing from stop light to stop light) will never, ever see a difference.

But wind tunnels and controlled engineering analysis obviously must have demonstrated enough of a difference to motivate a penny pinching GM to spend the bucks making the mold, the tooling, the part, and the labor production time to tack it on... all during the days of decontenting other more customer friendly parts like the glove box light, the dual panel sunvisors, the underhood light, etc. So apparantly GM noticed enough difference in lifetime average corporate fuel economy for their accountants to justify the cost and manufacturing trouble to put on the air dam.

csheatz · October 8, 2008

GM wrote that the lower airdam was added to improve fuel economy, by managing airflow under the vehicle. GM also closed off the center hole in the intermediate air dam of GMC trucks and SUVs in 2005, in addition to adding the lower airdam, for the same reason.

Someone above suggested that the airdam increases the frontal area, and therefore assumed that mpg's would be worse with it on. NOPE. Lower air dams, when properly shaped, reduce the co-efficient of drag, and control eddy currents under the vehicle. That's why race cars and race trucks have them. That's why the Prius and other high efficiency cars have them.

People who use their gas and brake pedal a lot (racing from stop light to stop light) will never, ever see a difference.

But wind tunnels and controlled engineering analysis obviously must have demonstrated enough of a difference to motivate a penny pinching GM to spend the bucks making the mold, the tooling, the part, and the labor production time to tack it on... all during the days of decontenting other more customer friendly parts like the glove box light, the dual panel sunvisors, the underhood light, etc. So apparantly GM noticed enough difference in lifetime average corporate fuel economy for their accountants to justify the cost and manufacturing trouble to put on the air dam.

I agree they could have put more time and money into other things, i hate my door panels, they are the same plastic lookin crap for the whole line up!

I will watch the MPG's next weekend. I usally average about 18.5 for the trip up (doing 68-70) and about 18.5 on the way home (doing 75-85). I will post my results after I get back. If this is only going to cost me .25 mpg i wont miss them. I would love to get 20+, but i have pretty much threw in the towel on that idea.

mbrannon · October 13, 2008

Took mine off this weekend. I noticed a little more wind noise. Haha The truck did seem to want to swap lanes a little at 70+...and I lost about .5 mpg going to Longview and back...But I think it looks sweet... What kind of milage did you get after removal?

HawkeyeOC · October 13, 2008

People who use their gas and brake pedal a lot (racing from stop light to stop light) will never, ever see a difference.

+1 Never have seen a difference

Nice that GM made it so easy to remove

NFSGamerUSA · October 13, 2008

I took mine off a few months ago, it looks so much better without it. I've never noticed a difference, but then again, I don't do a whole lot of highway driving. Even then I wouldn't expect more than a few tenths of a MPG less than with it on. It would be interesting to see the difference it makes in a wind tunnel, though.

18702GMT900 · October 13, 2008

The lower air dam is suppose to help with fuel economy; with it on you suppose to get .5 to 1mpg more than i you have it off, for me this only apply when I'm on the highway. I did a comparission before I removed mine a week afer I got my truck.