Jump to content

Gas Mileage Mpg Increase With Air Deflector Extension

disarticulate

Recommended Posts

disarticulate Enthusiast

disarticulate

Posted
Posted

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

 

GH07005.gif

mhenshaw Senior Enthusiast

mhenshaw

Posted
Posted

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.

disarticulate Enthusiast

disarticulate

Posted
  • Author
Posted
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 Senior Enthusiast

mhenshaw

Posted
Posted
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 :rollin:

 

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.

  • 2 weeks later...
sic lsx Senior Enthusiast

sic lsx

Posted
Posted

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 Enthusiast

kawtoy_77

Posted
Posted

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 Senior Enthusiast

SouthCo

Posted
Posted

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.

  • 2 weeks later...
00Silverado4x4 Senior Enthusiast

00Silverado4x4

Posted
Posted

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 Enthusiast

wavery

Posted
Posted
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.

  • 2 months later...
=v8-only= Enthusiast

=v8-only=

Posted
Posted

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 Senior Enthusiast

sic lsx

Posted
Posted
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

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Another JR
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By Another JR · Posted

      Have considered installing a DC to DC charger in your camper to replace your isolator?  
    • newdude
      Gas fill door

      By newdude · Posted

      Common failure.  You need to replace the fuel door housing.   The painted cover transfers over to the new housing.  To remove the old one there is 4 spots where you poke the plastic to release it.  
    • newdude
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By newdude · Posted

      No such thing as regenerative braking on a pure ICE vehicle.     Regenerative braking is the re-capture of energy from electric motors and stores it in the battery pack.  So hybrids, PHEV and EVs have regenerative braking.     What you are seeing is the charging system changing modes is all.  Its likely entering charge mode for some sort of reason is all.  All of the charging modes will be listed below.   As for L10 vs D.  L10 turns off automatic grade braking.  L10 puts you in control of grade downshifts where in D it will automatically do it based on brake pedal position and other factors.  Otherwise L10 and D drive exactly the same aside from that one aspect.    Battery Sulfation Mode The BCM will enter this mode when the interpreted Generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2–3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.   Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met:   Windshield wipers are ON for more than 3 s. Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control module via serial data. High speed cooling fan, rear defogger, and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. The estimated battery temperature is less than 0°C (32°F). Battery State of Charge is less than 80%. Vehicle speed is greater than 145 km/h (90 mph) A current sensor malfunction exists. System voltage is determined to be below 12.56 V When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9–15.5 V, depending on the battery state of charge and estimated battery temperature.   Fuel Economy Mode The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 A and greater than −8 A, and the battery state-of-charge is greater than or equal to 80%. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5–13.1 V. When fuel economy mode is active, the generator is not charging, only maintaining open circuit battery voltage. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.   Headlamp Mode The BCM will enter Headlamp Mode when ever the head lamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.   Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 s.   Tow/Haul Mode (if applicable) Pressing the Tow/Haul Mode button located on the center stack, the vehicle system voltage is raised and the remote (non-vehicle) battery will be charged. Having the headlamps on will raise the system voltage and if the Tow/Haul button is applied it will not serve any purpose. The voltage is regulated between 13.9-14.5 V.      
    • jaszr2
      Active Grille Delete

      By jaszr2 · Posted

      Hello from Australia Just sharing that there is now a way to delete the active shutters entirely with just a plug in module. Opens up tons of room to light bars etc.
    • jake111
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By jake111 · Posted

      I have an observation and a question... 1) I watch the voltage closely because I have had to dial in the cut-in/cut-out voltages of the battery separator to my camper.  The "smart" charging drives me nuts.  Anyway, I noticed that when coasting for a while, and especially if lightly using the brakes (though not necessary), the voltage goes up from mid/high-13 volts to mid/high-14 volts.  Then it drops back down after stopping or going again.  Consistently!   The only explanation I can come up with is REGENERATIVE BRAKING!  Well, maybe that's a little bit of an exaggeration, but it's certainly free extra battery charging.   2) Driving on mountain roads I will use L and vary the max gear.  Things straighten out and I end up in L10.  Sometimes I leave it there for a while.  Is there any difference between L10 and D?   

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...