Gas Mileage Mpg Increase With Air Deflector Extension

disarticulate · July 8, 2011

I bought my truck a few months back and noticed that the air deflector extension had been taken off. After averaging between 16.5-17 mpg with a relatively conservative use of the gas pedal, I decided to try adding the deflector (GM Part# 25821880, #23 below). After putting it on, I've noticed an increase in mpg to 18.3. The mileage increase is seen especially on the highway, where I see about 23mpg going 55-60mph. Just thought I'd throw this out there for anyone looking for some tips for saving gas. Part cost me $75 at the dealership (same as gmpartsdirect shipped or you can get it from gmpartsgiant.com for ~$55 shipped).

Generalizing driving and gas prices. Even if you only get a 5% increase in mpg then at $3.50/gal the air deflector extension will pay for itself after ~420 gallons of fuel. If you fill up once a week at 24 gallons then it'll take you a little over 4 months to recoup your money ($75). From then on, it's all cheeeeeeeeeeeeese.

Cheers

mhenshaw · July 8, 2011

Funny because many of us have taken the airdam off and seen no decrease in mileage. You would never see 1.5 to 2 mpg difference by a 2" piece of plastic either, even if you were going 110 mph.

But glad your mileage is getting better.

tanked_darren · July 8, 2011

I get 18.3 easy on the freeway, I have no deflector and I have a canopy!

disarticulate · July 8, 2011

Funny because many of us have taken the airdam off and seen no decrease in mileage. You would never see 1.5 to 2 mpg difference by a 2" piece of plastic either, even if you were going 110 mph.

If being a statistical anomaly means that I get better gas milage, then woohoo!!

mhenshaw · July 8, 2011

Funny because many of us have taken the airdam off and seen no decrease in mileage. You would never see 1.5 to 2 mpg difference by a 2" piece of plastic either, even if you were going 110 mph.

If being a statistical anomaly means that I get better gas milage, then woohoo!!

Every little bit helps, but I choose looks over tenths of a mpg

Put a vacuum gauge on your truck and see how much that improves your mpg. Even though it doesn't do anything but modify your driving habbit.

BigBlueLB756 · July 20, 2011

I've got one double-chin I can't do anything about; be dammed if I'll add another one.

sic lsx · July 20, 2011

no change here when i pulled mine off! If anything its less drag, but either way its not enough to make a difference.

kawtoy_77 · July 22, 2011

I guess if you really wanted better mileage lowering it might help, but I want my truck to look like a truck not an El Camino.....

SouthCo · July 22, 2011

I'm an oddball I guess. I took my chin spoiler off about 4 months ago because so many people posted how much better it looked. I still haven't gotten used to it. I'll probably put it back when it cools off some (100 with heat index sucks). Not because of mpg though, I just like the look on mine better with it.

00Silverado4x4 · August 3, 2011

I finally took my "lower lip" off about 3 months ago. It was broken anyway, it's at the local recycle center now & I haven't looked back. No more dangling plastic, I like the look better, no noticeable change in driving or mpg. Now just need a replacement lower part of bumper. I caught a rock years ago & just haven't replaced it...

wavery · August 3, 2011

After averaging between 16.5-17 mpg .............After putting it on, I've noticed an increase in mpg to 18.3.

There is NO WAY, outside of controlled environmental lab/wind tunnel/dyno testing, that an increase of 1 MPG can be attributed to anything more than environment (wind direction and humidity are huge factors), terrain, tire pressure, driving habits or just plain coincidence.

One cannot verify chemicals, spark plugs, wires, throttle body spacers, superchargers, air filters, air dams or any other add on part without strict lab controlled tests. "Gut feeling" just doesn't cut it and emotional factors play a huge part in this stuff. Once one does somthing like this, it becomes "personal". That's not to say that anyone is making anything up. It just says that most people become invested in this stuff (emotionally) and have a desire to share their perceived success but most of the time, that's all it is.

=v8-only= · October 18, 2011

i had the same change on my inst. fuel mileage on the truck.

when i first bought the truck i reset the mileage indicator and i do tons of highway driving for work. I was getting steady 18.6 mpg on every tank for months. I finally took it off for extra ground clearance and noticed that the truck would never go in 4 cyl anymore and mpg went down to 16ish. Put the spoiler back on it within a few weeks the mpg went back up to 18.

The only real way to verify the change is to reset the average MPG and comparing it before and after.

sic lsx · October 26, 2011

I'm an oddball I guess. I took my chin spoiler off about 4 months ago because so many people posted how much better it looked. I still haven't gotten used to it. I'll probably put it back when it cools off some (100 with heat index sucks). Not because of mpg though, I just like the look on mine better with it.

yeah not as big on a gmc i think it looks better off of chevy. if i had a 2wd i would keep mine on. just makes my truck look a ext 4-6" taller in front lol