I get about 15.5 to 16 driving in town, but I filled up with no ethanol gas and got about 18. So I am going to start using no ethanol all the time

 

26,000 kms and with winter slowly creeping in I'm down to 13 mpg and that's ~90% city driving. In the summer I'm usually around 18-19 mpg and the best I've hit was 23 mpg all highway.

 

My Unlimited Diesel, with 33" Cooper STT tyres, on a run down through France, doing a steady 65 mph, i got 28.7 mpg.
Driving around where i live, Devon in the UK, i normally only get 21-22 mpg.
Fuel over here is £1.10 per litre.
Mine is a Auto, and to me to high geared, needs 4.10s, not the 3.2 or what ever it is.

 

I want a diesel!!!

 

I just did a 600 mile round trip.

Tail wind 22 mpgm going 70 mph, headwind home 16.7 going 65 mph.

Aero of a brick, so tailgate semi's till they get pissed.

 

At the end of the study, it all comes down to common sense which isn't so common.

* slower acceleration: What acceleration
* reduced top speed: The speed limit is a good starting point.
* proper tire inflation: 30+ psi
* using cruise control
* proper vehicle lubrication
* correct transmission gears: Get those 5.13s if you have 35s.
* using air conditioning only when necessary: Sweat a little.
* reducing aerodynamic drag: keep your Avon off the roof.
* removing excess weight: Don't expect good MPG with 1/2" plate bumpers and 20,000 lb winches

• From the Summary section of http://www.omninerd.com/articles/Imp...uel_Efficiency


What I think is much more interesting is the data that was collected which shows the PCM behavior.
Unfortunately, the data was collected on a TJ.


Is there a cheap OBDII tool for the JK?
Obviously the programmer manufacturers have one that can read and reprogram the PCM.
But it would be interesting to understand what the PCM is programmed to do under different operating conditions.

The PCM in its stock form is not our friend.

 

17-18 city / 21-23 hwy. I swear these things loath going faster than 50 mph! Luckily mine rarely see's the freeway.