Thats because 1700 to 2300ish is the sweet spot with this motor. Lugging it down at 1200 to 1400 is to low.

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2008 KK Liberty Sport NIGHT OPS EDITION + GILLS
OEM & Custom Skids - Factory Tow Package - Rock Lizard Skink Super Sliders
Prototype JBA 4 Inch Lift - JBA UCA's - Flowmaster Super 44 OR - Whacked Resonator
Jet Stage 2 - RL Gecko Basket Rack - Custom Winch Bumper - Recon 10.5K Winch

X2................

Lugging it that low of rpm will drastically reduce mpg's.

I respectfully disagree. We bought a Dodge Nitro in July of '07 and traded in on this KK. It up shifted and down shifted as it should and kept the RPMs in the low to mid teens around town. You can not achieve get better fuel economy by turning an engine faster. To increase RPM you must increase the amount of air and gas entering the cylinders. If you increase RPM you increase fuel consumption, no way around it. The engine is not lugging at the lower RPMs and as long as it downshifts when you crack the throttle so it is responds and accelerates, why turn it faster to maintain the same road speed? Our Nitro worked very well in this respect and routinely gave us 17 MPG around town and 22 on the freeway - same motor, same gear, worked great for 4 years. Don't get me wrong, we love this Jeep, it is quieter at all speeds than the Dodge and rides nicer too boot.
YMMV (pun intended).

According to my ScanGauge II, have to agree with this. I was proved wrong, as I thought, lower rpms = less fuel consumption. Maybe one day I can record the MPH/RPMs/Instant MPG or GHP (Gallons Per Hour). I'm going to throw a wild guess and say at 1200-1400 RPM, there's not enough power to keep the tank moving and it struggles, but at 1700-2300 range, it's enough to keep a momentum. My ScanGauage II is usually 1-2% off my actual MPG, depending how heavy my foot was that tank

Now all this I stated above was for highway, not city. So with city, there's too many things to take into consideration (traffic, frequent stops/lights, uphill/downhill, etc).

With my previous car, the lower RPMs = higher MPGs was possible. Going 40MPH at 1200RPM resulted in 28MPG.

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His: 2004 Jeep Liberty Columbia Edition, Stock - Front Tow Hooks, D-Ring Receiver, Flowmaster Super 44, GY Silent Armors.
Hers: 2012 Jeep Liberty JET, Stock - D-Ring Receiver

My dad just traded in an 07 for an 11 and he's been pretty disappointed with the mileage, even though he has around 15k on it now. Basically it's getting the rated mileage, whereas his 07 generally beat the EPA estimates from what he's said.

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Black 09 Liberty Sport
Popular Equipment Group
Tow package

Every engine has a peak torque,a specific rpm that the engine produces it's max torque and no the 3.7 does not make 235lbs-ft of torque from idle to redline.At that peak torque rpm the engine is the most efficient and the closer you you gte those rpm's to that peak torque the better ecomomy you will get.The 3.7 is sadly a high rpm engine,makes most of it's power in the higher rpm range.


Case in point with my Liberty.Everyone say's keep the speeds to 65mph or less to get the best mpg's,false.At 65mph my KJ was lugging at about 2100rpm's and constantly downshifting and kicking out of lockup to maintain speed,result was a best of 16mpg's at 65mph.Now I would kick it up to 78mph with the rpm's in the sweat spot at 2900rpm's and would return almost 22mpg's(21.9mpg's hand calculated,speedo correct) and no more downshifting or kicking out of lockup and this was achieved with a lifted KJ running 265/75R16 MT's on steel rims with a total vehicle weight of 5500lbs and 4.10 gears.Granted now with 5.13 gears I'm turning 2900rpm's at 65mph so that is now the sweat spot for my KJ.

wow definitely going to have to try that out tomorrow up to CT

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2012 KK Cherokee * Arctic by Musclez * Mineral Gray
- Too Much to list BUILD THREAD

Just remember I have a different trans then you do(45RFE to your 42RLE),your speed will vary for the KK's "sweat spot" but it ain't 65mph or less.

That matches my experience with the KK too. I get my best mileage on the interstate doing 65-70. I rarely drive much faster than that so I can't say what would happen at higher speed. To be fair, part of that is probably that 60 mph driving generally includes trips through little towns which is going to hurt your mileage.

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Black 09 Liberty Sport
Popular Equipment Group
Tow package

That's why the decent MPGs. If you watch the RPM needle, these things are running their most efficiently at about 47-60