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Discussion Starter · #1 ·
Ive seen several threads on the fuel economy of the JK not meeting expectations.

As has been discussed ad nausium elsewhere, there are a great many factors in determining fuel efficiency.

Chief among those factors would be the absence of the label "JEEP" anywhere on the vehicle. If you are after fuel efficency....JEEP aint it.

That being said, there are also factors which can make the JEEP more efficient.

Primarily.... driving technique.

But first, lets make sure we compare apples to apples.

I have a 2012 JKU Sahara. 3.73 Limited Slip Differential. Stock tires/wheels unlifted. I average 18.2MPG for the 2 weeks/1000 miles that I have had it

on level asphault with the cruise control steady for several minutes I turn:
1800rpm @ 50mph
2100rpm @ 60mph
2500rpm @ 70mph

I try to stay under 3000rpm when under normal driving conditions.
I understand that the accelerator is a variable control device and not an on/off switch.
And I coast before braking at lights, etc. But I am far from being a Granny-driver. Im simply a mature driver.

once the base-line is established then you get into other variables such as tire type/inflation/alignment. Resistance (aerodynamic as a brick), parasitic drag (boxy rear-end causes a vacuum behind the vehicle INCREASING the drag holding the vehicle back). weight. air density. etc etc etc.

There are things you can buy to get better mileage...the list is long...some work but some dont...and ultimately it goes back to the best way to get great mileage is to buy something with an "H" in the brand.....(dont hurt yourself...I'm referring to Honda)

also, keep in mind that pricipals of fluid dynamics and aerodynamic compressability show that the faster you go...the more power (fuel) you are going to use. It takes more and more effort to push the air out of the way, and it isnt a linear change. There is a reason they settleded on 55mph back in the late 70's as the most "efficient" speed. But we are prone to ignore the lessons of the past, in favor of immediate gratification. No, I cant drive 55, either.

Interestingly, my wifes corvette has an "Instant mileage" feature which shows the "live" MPG consumption. I've tested it at 55mph and at 75mph. Flat. level. clean. Cruise. Sure enough....the faster you go...efficiency starts dropping-off pretty quick. 33mpg at 55.... 28mpg at 75... And its a pretty aeordynamic vehicle.

In summary. Please just remember that the most important factor in getting the best mileage from your fuel...and your vehicle...is the 3 pounds of grey matter positioned slightly above your shoulders. Use it wisely.
 

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The only error I can find in your post here, is the assumption that people actually know how to use the grey matter positioned above your shoulders. :doh:
 

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I did a very similar thread about the 3.8 a while back.
One thing to keep in mind is that you can burn a lot of fuel lugging the engine as well. Sometimes, you just need to downshift. Same applies for autos and manuals. I got so sick of hearing about people complain that their 3.8 couldn't pull up a hill, but none of them would ever downshift to get the rpm where it needed to be. OD is designed for flat, lever roads, not pulling up hills. I don't care what you're V8 truck or sports car would do, you have to learn how to drive your Jeep properly, because it's a lot different than your V8 truck or sports car.
 

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Discussion Starter · #4 ·
I have faith...

Until they demonstrate otherwise. :)
 

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Discussion Starter · #5 ·
I did a very similar thread about the 3.8 a while back.
One thing to keep in mind is that you can burn a lot of fuel lugging the engine as well. Sometimes, you just need to downshift. Same applies for autos and manuals. I got so sick of hearing about people complain that their 3.8 couldn't pull up a hill, but none of them would ever downshift to get the rpm where it needed to be. OD is designed for flat, lever roads, not pulling up hills. I don't care what you're V8 truck or sports car would do, you have to learn how to drive your Jeep properly, because it's a lot different than your V8 truck or sports car.
DIng! DING! Ding!

Thats why its called "Driving" and not "steering" lol.

There is more involved than merely pointing the direction you think you want to go.

Sure, theres a place for romp-and-go driving....can be fun at times.

But there is also a lot of fun to be had in finding the nuances of technique to get it to do what you want.

Not unlike crawling over rocks, I imagine.
 

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I've tried telling people it's your driving habits, not your Jeep. I average 17-18mpg per tank, mostly local suburbs and small town driving. On the highway, I've gotten just under 25mpg on a 350 mile round trip. I've never had trouble getting up a hill when I let my auto shift out of OD. I'm on stock tires and only a small lift. I don't granny it, I do the speed limit everywhere, but I don't do more than 5mph over unless on I-95 or something, where I just keep up with traffic and typically hit the slow lane and average 65 mph. I've tried giving fuel saving tips, tips on getting the most our of your Jeep, but the same complaints persist with some people. 99% of people can see a noticeable increase in their fuel mileage by making a few easy changes to their driving habits. But complaining is easier.
Maybe I'm just cranky today. :D
 

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I know what ya mean. I used to accelerate too fast and not coast to a stop light. I've started changing that and I noticed a slight increase in my mpg. It may be a small increase but it's still climbing
 

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Discussion Starter · #9 ·
Some folks are victims of superficial thinking.

They fail to understand cause and effect relationships.

the 10-or-so hours of operation effects the 10-minute refill.

For me, it all clicked when I did the math and figured out that every 1-MPG = $300 per year for me....cuz I drive A LOT. when I get to 20mpg....I'll be spending $600 per year LESS on fuel than I do at 18mpg.

Translated into "What have you done for ME" terms....that means that driving sensably PAYS FOR A SET OF TIRES EVERY TWO YEARS.

DUH!

If I can increase my mileage by simply driving rationally. I can save A LOT OF MONEY...which I will simply blow somewhere else.

And, again, its MINOR changes.

I dont WANT 30mpg.

I want a Wrangler. and I know thet means visiting my local fueling station with reasonable frequency. But I do what I can to keep it to a minimum.

RPH = MPG
 

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I know what ya mean. I used to accelerate too fast and not coast to a stop light. I've started changing that and I noticed a slight increase in my mpg. It may be a small increase but it's still climbing
It's so much more than that, too. Every time you step on the gas pedal, a surge of fuel is injected into your cylinders. The sharper the application of throttle, the larger the surge. Slower applications of throttle from a standstill and while moving can really help out your mileage as well. Don't drive with the throttle, maintain speed with the throttle. The smoother you are on the gas pedal, the better your mileage will be.
Things like Air/Fuel meters and the instant MPG computers can really help teach you how to drive more efficiently, should you care to learn. If you own a smartphone, there are apps with can turn your phone into a real-time data monitor via the OBD2 port in your Jeep. These are great, affordable tools. I have an Android phone, and use an app called Torque. It's cheap, so just spring for the paid version. Then you just need a USB OBD2 reader, which can be had on ebay for under $30. Things as simple as seeing how much throttle you're actually applying at a given time can really give you insight on where you could do better with your mileage. Plus, torque has some fun stuff like horsepower and torque simulators, and 1/4 mile timers.
 

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Discussion Starter · #11 ·
Cool.
Im gonna get me one of them varmints.
 

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Great subjective thread. I use the word "subjective" because, as you mentioned, fuel efficiency is largely based on the driver once all things are equal. Personally, I'm ranging about 16mpg and I just broke 100 miles. I have been breaking in my engine so its been just inner city roads and fluctuations in acceleration. I drive about 1,000 miles/month and pay $3.59/gallon (regular). Driving conservatively, I could probably average 21 mpg. If I drive like I am now, with accelerations sometimes peaking over 3k, I'll average 16mpg. For me that difference between 16 and 21 equates to about $641/year. If after my break-in period I decide to shoot for somewhere in the middle like 18mpg, I could cut that yearly expense in almost half $341.

In the end we all know these aren't fuel efficient vehicles and I budgeted my expenses accordingly, taking into account a 4% annual rise in fuel expenses.
 

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Discussion Starter · #14 ·
Yeah, I wouldnt give MPG a passing thought during the break-in period because your driving habbits arent "normal".
Even following the owners manuals instructions for break-in will goof up your mileage.

In my personal opinion...for the first oneor two thousand miles, getting to know your vehicle is more important than milking the tach for efficiency....stick with the break-in guidelines and worry about efficiency later.

Im at 1000 miles now (in the JKu) My first tank was 17.1 each gets slightly better. I think that after my first oil change I'll hit the fabled 20mpg mark and be pretty content.

For now, I just track it for ammusement.
 

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Discussion Starter · #17 ·
its the distance your wife has to sit from you after you eat enchiladas for dinner.
 

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Mr. Sinister said:
It's so much more than that, too. Every time you step on the gas pedal, a surge of fuel is injected into your cylinders. The sharper the application of throttle, the larger the surge. Slower applications of throttle from a standstill and while moving can really help out your mileage as well. Don't drive with the throttle, maintain speed with the throttle. The smoother you are on the gas pedal, the better your mileage will be.
Things like Air/Fuel meters and the instant MPG computers can really help teach you how to drive more efficiently, should you care to learn. If you own a smartphone, there are apps with can turn your phone into a real-time data monitor via the OBD2 port in your Jeep. These are great, affordable tools. I have an Android phone, and use an app called Torque. It's cheap, so just spring for the paid version. Then you just need a USB OBD2 reader, which can be had on ebay for under $30. Things as simple as seeing how much throttle you're actually applying at a given time can really give you insight on where you could do better with your mileage. Plus, torque has some fun stuff like horsepower and torque simulators, and 1/4 mile timers.
I know it's more than what I said but you gotta start somewhere
 
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