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Have about 650 miles on my new JKU. 3.73, auto and recently swapped the Sport S wheels / tires for a set of Rubicon take-offs.

I have been getting just a skosh over 15mpg in conservative city driving. When I rented a 2012 Sport S with 3.21 and auto, I ended up getting just over 20mpg in mixed driving.

I am surprised at the big difference! I know, these aren't great on mileage, I guess I was expecting to get more like 17+. Do Rubi tires and 3.73's eat that much more fuel or should I expect some modest improvement over time?

I appreciate any thoughts or other experiences like this and if it got any better.

Cheers!
 

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First, your not getting accurate mileage readings if you didn't recalibrate your speedo.

Second, your talking about considerably more rolling resistance and weight with those new tires and wheels.
 

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Discussion Starter #3
First, your not getting accurate mileage readings if you didn't recalibrate your speedo.

Second, your talking about considerably more rolling resistance and weight with those new tires and wheels.
I agree on the rolling resistance, but the tires Sport S tires were:confused: the same size as the Rubicon take offs - 255/75/17 so shouldn't the calibration be fine?
 

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I was disappointed with some milage figures I was getting and kept resetting the computer. Up hill, down hill-100 miles each way--around the hood and around town. Yesderday, I went out for a long ride of hwy, 50 miles of dirt road, trail, mud, rocks, crawling, 4hi, 4lo, some hill decent etc just to practice and have fun. More dirt road, twisting mountain roads, climb to 8000' and down to 3500' then back to 5000', more hwy, long(50 miles) hill climb back home. Result 19.5mpg and about 200 miles. I am now up to 540 miles. I feel like the Jeep is coming around on the milage. We'll see. 2013 Rubi with 3.73 and auto trans.
 

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Super T said:
Have about 650 miles on my new JKU. 3.73, auto and recently swapped the Sport S wheels / tires for a set of Rubicon take-offs.

I have been getting just a skosh over 15mpg in conservative city driving. When I rented a 2012 Sport S with 3.21 and auto, I ended up getting just over 20mpg in mixed driving.

I am surprised at the big difference! I know, these aren't great on mileage, I guess I was expecting to get more like 17+. Do Rubi tires and 3.73's eat that much more fuel or should I expect some modest improvement over time?

I appreciate any thoughts or other experiences like this and if it got any better.

Cheers!
2010 Sahara JKU 3.73. City I get a fabulous 9-11 mpg. I have never ever seen close to 15 city. Highway 20-22.

I would be ecstatic to see 15 mpg city.
 

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I was disappointed with some milage figures I was getting and kept resetting the computer. Up hill, down hill-100 miles each way--around the hood and around town. Yesderday, I went out for a long ride of hwy, 50 miles of dirt road, trail, mud, rocks, crawling, 4hi, 4lo, some hill decent etc just to practice and have fun. More dirt road, twisting mountain roads, climb to 8000' and down to 3500' then back to 5000', more hwy, long(50 miles) hill climb back home. Result 19.5mpg and about 200 miles. I am now up to 540 miles. I feel like the Jeep is coming around on the milage. We'll see. 2013 Rubi with 3.73 and auto trans.
Glad to hear the mileage is "coming around." I have the same year and tranny as you in a Rubicon with the BFG stock MTs and after 300 miles I am barely topping 16 MPG city. Hoping to get close to the EPA numbers as it breaks in. :popcorn:
 

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i got a 12 rubi manual 14k miles. i hover between 16-17 city/highway commuting from nj to nyc. sometimes i see 18.5 on the highway. never saw above that.
 

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pluke the 2 said:
Lol.. Does it matter
Lol RIGHT!!

I find it funny that my "piece of junk" 3.8 rubi with a heavy bumper and winch hanging off the front or it got 20/24 mph highway 17/19city.

True it dos not get that good anymore.
 

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I have a stock '13 jku sahara, and i get 16.5/city and 20/highway.
 

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I have a 2013 stock Sahara w/3.73. I noticed that mpg changed as the engine broke in and got progressively better. After 2000 miles, I'm seeing about 18,5 mpg that involves lots of mixed road driving. I'll be curious to see what I get on a long highway trip.
 

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I agree on the rolling resistance, but the tires Sport S tires were:confused: the same size as the Rubicon take offs - 255/75/17 so shouldn't the calibration be fine?
not necessarily even tho they technically should be different manufactures and models of tires can have different actually sizes vs marked sized. Your Goodyears may have been 30" actual tire size and your goodrichs may be 31.5" etc.
 

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Hard to compare mpg because of different driving styles. Some people like to mash it others like to cruise. I get a consistent 17-18 with mostly city driving. Also, did anyone notice improved performance after the breakin? Maybe it was that i stopped babying the gas petal.
 

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I have a 2012 jk sport s manual with 3.21 gears, 2,400 miles and seeing an average of 20 mpg with mixed highway and city. Highest ever was 22.2 all highway.
 

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jku would have to get worse mileage than a 2 door. My 2 door with rubi tires gets around 17- 18 mpg after i re-calibrated the speedo ( I had the 16inch steel wheels with 29 inch tires) Where I live there's not too much traffic though. I mostly lose mpg when i'm sitting in the fast food lines.
 

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Sorry, my phone kicked out in the middle of my post. I'm surprised that your sport had the same size tires as the rubi, most of them only have like 30" tires on them. The gearing will make a difference, but not that much. I only get 12-13 mpg around town, but I'm in an 07 JKU on 35s. I'd verify the speedo setting by using a GPS for a couple of tanks. They record your mileage and give you a far more accurate read on speed and mileage.
 

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Discussion Starter #18
I have a 2013 stock Sahara w/3.73. I noticed that mpg changed as the engine broke in and got progressively better. After 2000 miles, I'm seeing about 18,5 mpg that involves lots of mixed road driving. I'll be curious to see what I get on a long highway trip.
Thanks, that is helpful. I didn't buy for MPG, but it is nice to see it improve, even if just by a tad.
 

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I'm running 315/75-16 Nitto Terra grapplers (A/T's) Much bigger than the stock Rubi tires I took off and am getting BETTER gas mileage now than I was before.

Calculated and through the computer. I've re-calibrated for the larger tire.
 

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I have a 2013 Sahara Automatic with 3.73 gearing.
It now has 6500 and I do just over 50 miles one way
to work. The first half of it is doing 35-45 mph and the
rest is at 60-70 mph. I check it by running it down to
less than 1/4 tank and fill it and zero out the trip meter.
Then run it afew days and fill again and do the math.
It averages out to 22 mpg
Rob ....
 
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