Dorky air dam of Wrangler JK does save gas!

[The Swiss]

It appears that this dorky air dam below the JK stock bumper does save gas! :Wow1:

At around November, my JK suddenly lost some mpgs. I did not think too much, attributed it to colder temperatures, to winter gas etc. But the loss was greater than in previous years. Changed the air filter, made sure tire pressure was right, had the throttle body cleaned, no improvements. Temperatures warmed up, barely any improvement. Then about two weeks ago, I put that air dam below the front bumper back on the Jeep because it got in my way laying in the garage. To my utmost surprise, my mileage quickly went back to normal. Thinking back: The drop of mileage coincides more or less with the time I took the air dam off for a wheeling weekend; I then left it off because the Jeep looked better without it.

Call me crazy, but it is the best explanation I have for what is going on with my Jeep.

Just felt like sharing :elkgrin:

 

[Bigjerm]

I didnt notice any MPG change when I have my JK but I did see a change in hood bounce so I kept it zip tied on when no going offroad for awhile. On the Rubicon I just put a rugged ridge skid plate for the sway bar disco motor.

 

[RonL]

How much are you talking? 1-2mpg of 4-5 mpg?

 

[The Swiss]

How much are you talking? 1-2mpg of 4-5 mpg?

My "instant" calculated gain over 3 tank fillings was 1.783 mpg (would be nice if it would be 5 ).

Average, calculated fuel mileage for my Jeep

• Regular average mileage: 17.5 to 18.5 mpg
• Average mileage of the last couple months: 15.5 to 17 mpg

I have a 2.5" lift in the front and a 1 3/4" in the rear, which already caused some increased hood bounce. But Bigjerm is absolutely right, hood bounce was even more frequent (for not saying constant) without the deflector.

 

[kenallwine]

Not to go off topic but if you want to fix the hood bounce, put on some Daystar Hood Wranglers. I did that and the hood doesn't budge. I think they were only $20.00

 

[Bigjerm]

Seems like if a few minutes of work got you another 1.75 mpg for FREE then why not? Gas isnt cheap anymore. If I owned a JK still I would have it on

 

[Brazos609]

RVers used to put what essentially were mudflaps under their front bumpers to reduce the amount of airflow under the RV to increase mileage.

 

[fisher205]

I have found that on my Chevy pickups. I usually knock off the air dam about once a year. A couple of zip ties fix it in a hurry. It figures into an easy 10% increase in fuel economy.

 

[Brazos609]

I think one of the 4x4 magazines even did an article with a test back in the 90s hanging a solid rubber flap almost down to the ground across under the front bumper on a CJ.