I know I didn't buy the 4dr Unlimited Wrangler for gas mileage, but isn't 12 mpg a little on the ridiculous side?

I have an 4.10's, Airaid CAI, Superflow 44, Superchips 93 performance setting. I know the 35's hurt gas mileage, but I went from 19 to 12, hand calculated by the way, not the onboard computer?

Do I just suck it up, or should I take off CAI, or use a different Superchips setting or something totally different?

Thanks!

 

4.10 and most everything else stock... i'm a little better than 12, ranging from 12.5 to 13 'city' type driving...

 

Gears?!

I get 15.5-16mpg combined (city/highway) with 5.13s and 35s and the AEV procal to recal things.

If I were doing an all highway trip and could keep it around 60-65mph, I think I could maybe get 18+mpg out of it...

 

Did you upgrade to 4.10 gears in your Sahara?

Most Sahara's have 3.73s from the tow package.

The auto doesn't provide the flexibility of the manual when it comes to gears.

I average ~16 MPG with 35's, auto and 5.13s at 75-80 MPH.

 

Sounds about right... I have a 2 door 6 spd with the stock 321s and 35s and I get between 12-15. I am going to be regearing to 513s soon so that should help

 

I will have to call the dealer back, as I called once for them to tell me the gear ration, and they told me 4.10, but you are right I do have Sahara with towing package, so I will call again to double check.

If I have 3.73's then regearing is a nobrainer huh? Except for that little problem called "CASH"!!

 

I just went from 3.73 to 5.13's. My mileage went from 14.7 to 16.3 with the gears. Thats 50/50 city/highway driving too. I dont go over 65 though...

 

Mileage will improve by re-gearing, but it is not the primary benefit, either IMO. You will have a much more drivable vehicle, especially if you use any highways...

 

I must drive like an old grandpa . . .

I lost 3-4 MPG when I added my 35's but still get around 18-19mpg hwy driving with 3.73s and 6speed. I can still get over 20mpg (though not much over) if I drive 55mph. Of course, most of my driving is flat roads too so that I am sure helps a lot as well.

As a side not, is it a bad EGR valve that can cause such a huge decrease in mileage or am a thinking something else?

 

As your instruments (Like the ODOMETER and SPEEDOMETER) take the rpm off of the tail shaft, when you regear, (And/or get larger tires, etc...you change the rpm for any given speed, and this makes the miles you thought you drove, and the speed at which you thought you drove them WRONG.

So, its POSSIBLE that you went more miles than the odometer said you did, and, that you were going faster than you thought you were, both of which, or either, will make you hand calculate a loss in mpg.

The dash read out would of course be fictional as well, etc.



Using a programmer, etc...to correct for the gearing and/or tire changes can fix all that of course.


For example, if you went from 32's to 35's, you dropped your RPM at any given speed by ~ 8.6%

If you went from 3.73's to 5.13's, you INCREASED your RPM at any given speed by ~ 27.3%

The net change in RPM is ~ 18.7% higher RPM at any given speed.

That would make you drive SLOWER than you thought, but drive a shorter distance than you thought as well.


If you were getting, say 14.7 mpg on 32's and 3.73's.....your apparent mpg might GO UP to perhaps 16.3 mpg or so on 35's and 5.13's.





Food for thought.