AutoJunkieMan

No but i should be fine, i am using a 6 speed and i wont be towing more then 1500lbs. If tanny overheating is an issue could always install a cooling unit.

AutoJunkieMan

I was looking at my fuel economy pretty close now with the digital gauges, I look on the Jeep site it says 12.6L/100kms and 22MPG city, 9.3L/100kms and 30MPG Highway. Im scratching my head thinking really.. My dash is showing my average 12L/100kms (i probably still need to break my motor in some more it's at about 1700kms) But when i swap it to imperial its show 19.9MPG. Huh? So I do a conversion and sure enough american converts to 19.6MPG but thats not 22MPG.. Are they lying? Whats going on here! Conspiracy! Nope.. there displaying the british MPG which is around 23.5MPG.

So i don't know what these guys are trying to do, but it's very weird discovery. I run around 100km/h on the highway about 2000RPM or so, I find if I ride at 110km/h my eco goes from 11.8L/100km to 12.8L/100km.

If anyone knows when my engine break in should be complete let me know, or if I did something to mess it up. But everyone keeps telling me that I am still in my "engine break in" period, but the manual says 500kms is your engine break in period and I drove upto Midland on the highway for the day and did 500kms in 2 days of driving!

Sin41

iTrader: (1)

after installing new tires( 33") and other mods, my fuel went berserk. Right now my dash is showing 16 L/100 km in the city or 14 mil/Gal. very bad....

JTPhoto JK

Don't go by the dash readout. It is averaged over the past 500klm unless you reset it. I use it only as an indicator to whether I'm getting on it too much.
Accurate mileage can only achieved by manual calculation. First use a speedo app or GPS to determine your true speed with the new tires. From that you can determine the % that your speedometer / Odometer is out.
For reference I get 17-18mpg (13-14L/100klm) combined, with 35" tires and a programer.

JTPhoto JK

The reason for the discrepancy is they are converting to Imperial MPG (Imerial gallon is 4.54L) on the site but you dash gauge converts to American gallons (3.78L).

trigger

i just use regular, not brand specific in my WJ and i seem to get about 475km to a tank running about 70% city driving. i have the 4.0L I-6 with the dana 30/35 axles, and i can tow my 12' single axle enclosed trailer (decked out for construction, holds all my tools, etc) with out much trouble. towing cuts my fuel economy by about 25% it seems. the only thing i have done to my motor so far is a K&N filter, and a 1" TBS. once i install my lift and my 32's should i be considering different gearing to keep everything copacetic?

Sin41

iTrader: (1)

Today I fill up with Petro Canada 89 octane, just to see how it goes. No difference, actually I noticed somehow slower acceleration vs Regular 87 .

Maverik

I have a 2012 auto jkur 4:11's and stock on a 4000 km trip across the states i got anywhere from 11L/100km to 13L depending on the mountains to flat, or interstate 80 mph to 55 mph. When i put 33's on i actually get a little worse around town and a little better on the highway. Yes i said better, 100km cruising dropped my rpm 100-150 rpm with 33's and i get slightly better mileage. A 12 with auto and 411's is geared really low compared to anything earlier. If u change your tire size from stock to 33's your speedo will be off a little over 5%, this means your odometer will also be off 5%, which is a double whammy as far as mileage is concerned on your computer. As JTPhoto said, figure it out manually and get a AEV procal or a tuner to set your tire size correctly. In general american gas seems a little better then our Canadian stuff. I like to throw a tank of high test in every once in a while, it seems to get a little better mileage and work slightly better....but no where near worth the money to run all the time. Need a tuner to get the bang for your buck out of high grade. I like sunoco gas if i can get it, seems to be the best for me. Probably depends on the station,tanks and how fresh it is more then the brand.