well i decided to calculate out my mileage and it looks like im getting 21.66 MPG i'm not sure what it would be without the efan cause i put it and the 31's on close to the same time. before each i was getting 22.5 so thats not bad if i calculated it right

 

well i took my odometer reading of 340 miles then went to tirerack and found that with the stock tires 724 revs = one mile so 340 *724 = 246160 revolutions for that tank of gas then i found that with the BFG's 677 revs = one mile so 246160/677=363.604 miles is actually how far i went. then 363.604miles /16.785 gal. of gas = 21.662 MPG

 

thats still good, i get like 19 or so...

 

i got 280 miles on my last tank of gas with the E-fan, 4.0L, and 31s, I dont know what that calculates out to, cause i dont know what size tank i have, but its the best i have gotten since i bought the truck.

 

look at the tire you have and click on specs its to the far right

 

i dont have the efan, 31's, 3.0, and only get about 16mpg. any thoughts on why its diferent?

 

I don't know... I get about 17 average... on a trip I pulled 19.5

 

driving style, type of roads alot of factors...

 

mostly a highway doing an average of 65. but still....im at ~2300 rpm at 65. give or take. 2500 rpm even at 70 mph. kinda weird. wish i could get it up to about 18mpg.

 

My mom's Liberty only runs 1500rpm's at 55... crazy man!

 

my moms grand cherokee is like that too. highway she gets like 22-24 mpg. pretty nice

 

you have 4x4, i have an underdrive pulley, and the efan, and a tuner. those could be factors and i also just remembered today that was with hauling my new 4 wheeler 80 mile too

 

mines only at 1800 at 55, our taraus with the same engine goes 65 at 1500 i think, its not fair lol...

 

average 14-15mpg around town normal driving with 33's and 4.10's on the highway i once got 20mpg.......it was a good good day

 

you need to know how much your speedo is off to use a correction
my speedo is actually Accurate within .5mph at 70 with my 265/75R16's
with the stock size it was off by more than 2mph.

I would recommend a GPS on a straight flat stretch of highway at say 70mph
and you can see what the gps says you are doing.

Because while its easy to claim 5% speedo difference when you upsize your tires
chances are it was off the other way with the stock tires...

That all being said with my heavy 32's (load range e) 4x4 and 4.0
I have gotten between 18.2 and 19.1 for the last 5500 miles..
average is something like 18.65

 

good point. forgot about the big 4x4 factor in there. that sucks. my engine is COMPLETELY stock though. so you think if i do the efan, cold ari intake, and maybe a chip i can get it up to bout 18 or so?