[Rivi]

Originally Posted by XabuJr

Because it's a Jeep. If you wanted something with 30mpg you should have bought a Honda. Most people aren't asking for a 3mpg gain, but rather something to take it from 13 to 20. If you want great gas mileage, use the smallest stock tires and pull all the weight you can out of it. Then drive like your grandma. Tell us how that works. The problem is most people are throwing 33's and bigger on their Jeeps then whining every other day about how gas mileage sucks. Go figure.

super hoofty!

[Rivi]

Originally Posted by halfmoonclip

Preheat the air, and use injector cleaner, presto 10-15% mileage increase...sorry, Rivi, color me skeptical.
All these years we've been trying to COOL the intake charge...

When considering a Jeep's gas mileage, we persist in comparing it to a four cylinder ricer or somesuch. Over the time I've had two XJs and the TJ, my bride has had entirely ordinary four door sedans. There has not been a big difference between our vehicles mileage-wise; my first Cherokee actually did better than her six-cylinder Ford. Currently, the Jeep and the VeeDub do about the same in shorter running, but the Wunderpanzer does much better at high speed, due mostly to low aero drag. Ask me about the bellypan mit NACA ducts I have to remove to change the oil.
So yah know, I do mileage for every tankful, of every vehicle.
For the record, the Volks has about the same weight, the same horsepower and torque (tho' at TOTALLY different spots in engine speed), and it drives thru all four wheels, all the time.
If we really want mileage out of Jeeps, we're going to have to abandon the barn shape.
Moon

you can beileve what ever you want....i guess GM used it since about 1968 because it doesn't workfor me i'll ewnjoy my jeeps power AND gas mileage......later

[Rivi]

i'm done posting on this,the gas companies thank GOD for americans like you everyyday!

[shaggy105]

Originally Posted by halfmoonclip

If we really want mileage out of Jeeps, we're going to have to abandon the barn shape.
Moon

BLASPHEMY!!!!!!!

[shaggy105]

Originally Posted by Rivi

i'm done posting on this...always the same result on these forums...no real knowledge gets passed on ...only BULLL SHEEEET!

I seriously disagree with you here... I've learned TONS of things on forums like this... prob. 80% of the stuff I know about my jeep I learned on these forums. That being said, I do agree with you when you say try it before you criticize it... Thats what this is all about people sharing knowledge. Me personally, i don't care about my gas mileage enough to take the time doing your mod for the possibility of getting 1-3mpg better. MAYBE if some other members jump on here and say yea do it cuz it def. works then I'll take the time to try it for myself, but prob. not LOL

[bluehdmc]

I don't see how preheating the air is going to help. Isn't there a mass air flow sensor that basically can tell the difference? (warmer air having less mass?)

[Rivi]

Originally Posted by bluehdmc

I don't see how preheating the air is going to help. Isn't there a mass air flow sensor that basically can tell the difference? (warmer air having less mass?)

[Red_]

14.7:1 Air to Fuel ratio blue

[Rivi]

ok let me explain onemo time,if you take a hooker out on a date and your wife catches you yer in divorce court!make sense now? i sure hope so!

[XabuJr]

Originally Posted by Rivi

ok let me explain onemo time,if you take a hooker out on a date and your wife catches you yer in divorce court!make sense now? i sure hope so!

Drink another!

[Rivi]

14 hookers to 1 wife its purdy easy to figure out

[ryobi]

Trying to understand. Did you mean "pretty" easy? By that reasoning, did yer mean "your"? I'm not even going to attempt to decipher "onemo".

Originally Posted by Rivi

14 hookers to 1 wife its purdy easy to figure out

[Red_]

In english a gasoline engine runs on a 14.7:1 air fuel ratio. That is 14.7 parts air to 1 part gasoline. For airflow metering our TJs use a speed density system that has a MAP (Manifold Absolute Pressure) sensor to guesstimate how much air the engine is sucking in (using your IAT and RPM).

[off topic]
A speed density system sees Air Mass not air flow, which is why most CAI setups dont work since the ECU is too dumb to see an increase in air flow. If you could pipe in some cold air, the ECU would see the increase in density and compensate [/off topic]

By heating up the air you are reducing its density. So lets say normally your ECU sees a mass of 147g of air coming in, so it injects 10g of fuel (14.7:1), but now that you have heated the air, whats coming in has a mass of 73.g so the eco only injects 5g of fuel. Thats where your mileage bump comes from. The catch is that a straight warm air setup trades a few more MPG for power.

[CGRLCDR]

I have an 05 Rubicon Unlimited with auto transmission and have vastly improved my overall MPG, cut my gasoline expenses and reaped a big tax credit.

I keep the Rubicon well tuned, use only Mobil1 5W30, keep the tires pumped up to 35 lbs, removed all excess weight from the vehicle, and drive it like an old lady. Also, I bought an 06 Toyota Prius and only use the Rubicon for off road, mountain bike adventures and top down good weather driving; otherwise I use the Prius. The tax credit is for purchasing the Prius before September 15, 2006.

Basically I gave up trying to improve the MPG of the Jeep itself. Once, just before they changed to winter blend gasoline in the northeast a couple of years ago, I got better than 20 MPG driving with the cruise control on at 55 MPH on flat highway for about 250 miles. However, I have not been able to replicate that MPG in the Jeep since and the best I can get if I try really hard is just over 18; normally driving around town gets me 14 - 15 MPG in the Rubicon. My new main vehicle (the Prius) gets in excess of 50 MPG average even with almost 9000 miles on the odometer.

Like a number of other folks have said here, Jeeps just don't get good mileage no matter what you do. Enjoy your Jeep for what it is!

[SpoiledRotten]

I'm glad I've got a Ford F-250 7.3 PSD. That thing gets great fuel mileage. My Jeep is just for fun anyway for me. I knew before I got it that they weren't built for gas mileage.

BTW, I have always heard that if you have to worry about the gas/fuel mileage, you don't need the vehicle.