Gas mileage

Oldbear

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My JL 2.0 is always mid 20’s running like 40% interstate. I’ll run 70-75 on the slab. Just remember that adding big tires adds a ton to unstrung weight And adds drag. You have to work to get those bad boys spinning and that take fuel. Lifting more than likely also increases drag on a vehicle that already has the aerodynamics of a brick. Put your foot in it to accelerate quickly and again, it burns a good bit of fuel.. My previous Wranglers were all low teens regardless of how it was driven (and that on stock tires(😳)..
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zdr

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Are you going by what the display shows or are you calculating your fuel economy manually?
How do you get exact calculations? Not being smart, just curious, if the mpg on the display is known to be inaccurate, wouldn't the fuel tank level also be inaccurate? I would think you'd have to run it to empty to get an accurate number given the reserve tank.
 

TheNewGuy

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How do you get exact calculations? Not being smart, just curious, if the mpg on the display is known to be inaccurate, wouldn't the fuel tank level also be inaccurate? I would think you'd have to run it to empty to get an accurate number given the reserve tank.
Fill your tank until the pump stops(dont top off). Reset trip odometer. Next time you fill your tank (dont top off) divide miles driven by the gallons pumped to refill.
 

zdr

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Fill your tank until the pump stops(dont top off). Reset trip odometer. Next time you fill your tank (dont top off) divide miles driven by the gallons pumped to refill.
Got ya. I'm just a little skeptical, sometimes the pump shuts off with like 1 or 2 gallons left. Not sure if each pump is different, can't think it would be that far off. I'll try to use the same pump lol.
 
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BadAssBumbleBee

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How do you get exact calculations? Not being smart, just curious, if the mpg on the display is known to be inaccurate, wouldn't the fuel tank level also be inaccurate? I would think you'd have to run it to empty to get an accurate number given the reserve tank.

I do pretty much what @TheNewGuy said, except I use the two click method when filling my tank......us two door owners can use every last drop of fuel we can squeeze into the tank LOL.

I fill my tank until the pump stops, wait 30 seconds and then continue filling until the pump stops again. Record the distance traveled at fill up, then divide the distance traveled by the amount of fuel pumped.
 
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sourdough

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My recent and first long road trip in my JLR, 3.6, automatic, 4.10 gears and 37" tires loaded to max. weight. It was a round trip from SoCal to Deadwood, S.D. at varied speeds from interstates at up to 80 mph and crawling trails during Jeep Jamboree. The math says about 49 MPH average :LOL:zoom zoom.
MPG from dash.jpeg
 

longfiredragon

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I did some research because every time I see this topic someone always says your gauges suck, they are not accurate, they are known for being wrong. According to several articles I just read (Which you can just google any time) This is not true of newer vehicles. Back some years ago yes they were not quite as good and edmunds (Which is one I usually trust found a somewhat wide spread diff. in cars, & diff. MFG about 5.5% to 19% but not in all)

There is a government standard that fuel gauges, fuel average gauges and current gauges MUST meet nowadays. And MFG's both automotive and gauge manufactures are continually monitoring, fixing and improving them. They still vary a little and sometimes because these gauges work in concert with your entire instrument package and onboard computer they can be negatively effected if something else is wrong or sometimes if something else is going wrong, but this is rare.

That said for the most part most of them (Gauges, fuel and other wise) are better than 99% accurate!

One person said it, if my current, and average fuels gauges are way off does that mean my fuel gauge is off to. The answer is yes and no. If there was something wrong, then yes all gauges could be affected, but if not they are actually very accurate.

Also for another example look at your tire monitor gauge, I have done this on my 2020 Ram. all 4 tires were reading the tire pressure was 38 psi. (They looked low to me) I have a good quality aftermarket gauge I use and I checked them, all 4 tires was dead balls on at 38 psi, exactly what the onboard monitor gauge was reading.

I could go more as I have been in the aviation industry for 35 years and have worked on fuel QTY indicators and such. The DOT, FAA and Fed. Gov. In general is very strict on any kind of fuel monitoring/reading devices, and of course Jeeps don't fly LOL, but the Auto industry has taken Que from aviation for years now and have insisted on more accurate computers and devices in cars.
 

BadAssBumbleBee

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Thanks rickinAZ, I appreciate the link.

I've been filling the gas tank on my Wranglers using the two click method for over 30 years and never once experienced any problems with excess fuel vapor or evap canister failure.

Maybe I never held on to a particular Jeep for long enough (more than 10 years) to see the long term results of using the two click method, but it's worked fine for me so far.
 

omnitonic

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I was getting around 24 mpg on a 70/30 mix of highway and city driving with my 3.6L 6MT and 3.45 gears. I was still at 21 mpg on a Rubicon takeoff lift with stock tires. Putting on a 2.5 lift and 35s dropped that to 17.

I'm hoping to get a little fuel economy back whenever the shop I contacted six weeks ago finally gets the parts in stock to do my regear to 4.56, but I am not expecting a miracle. My current 4th gear is fairly close to what I will be getting out of 6th, and I spend 70% of my time cruising in 4th gear. The only places the new gears are going to make a difference are coming off the line, and whenever I need to downshift. Both of those operations are real dogs on my current setup.

I didn't actually expect it to take 6+ weeks to get a set of gears to install. I thought I could have this done weeks ago. Coming up with the money wasn't the biggest obstacle, it turned out. Now I have $1100 tied up in this, and still no appointment in sight. Irritating.
 

TheNewGuy

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I did some research because every time I see this topic someone always says your gauges suck, they are not accurate, they are known for being wrong. According to several articles I just read (Which you can just google any time) This is not true of newer vehicles. Back some years ago yes they were not quite as good and edmunds (Which is one I usually trust found a somewhat wide spread diff. in cars, & diff. MFG about 5.5% to 19% but not in all)

There is a government standard that fuel gauges, fuel average gauges and current gauges MUST meet nowadays. And MFG's both automotive and gauge manufactures are continually monitoring, fixing and improving them. They still vary a little and sometimes because these gauges work in concert with your entire instrument package and onboard computer they can be negatively effected if something else is wrong or sometimes if something else is going wrong, but this is rare.

That said for the most part most of them (Gauges, fuel and other wise) are better than 99% accurate!

One person said it, if my current, and average fuels gauges are way off does that mean my fuel gauge is off to. The answer is yes and no. If there was something wrong, then yes all gauges could be affected, but if not they are actually very accurate.

Also for another example look at your tire monitor gauge, I have done this on my 2020 Ram. all 4 tires were reading the tire pressure was 38 psi. (They looked low to me) I have a good quality aftermarket gauge I use and I checked them, all 4 tires was dead balls on at 38 psi, exactly what the onboard monitor gauge was reading.

I could go more as I have been in the aviation industry for 35 years and have worked on fuel QTY indicators and such. The DOT, FAA and Fed. Gov. In general is very strict on any kind of fuel monitoring/reading devices, and of course Jeeps don't fly LOL, but the Auto industry has taken Que from aviation for years now and have insisted on more accurate computers and devices in cars.
When I bought a new 2017 Ridgeline it was consistently off my 1.5 +/- MPG between the onboard computer and calculation at the pump. The Ridgline forum was filled with other owners who had a similar discrepancy.
 

Mikeymiler

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I have a 2021 stock JL2 door Rubicon with about 1900 miles on it …on the highway I get 21 on average around town I’m getting 18.8. I am fixing to put a 2 1/2 inch lift on it and leave the stock 33 tires so I will see what kind of gas mileage I get with the lift

28913238-E953-4BA0-9A32-59628B8C91D4.jpeg
Update I have put on the two a half inch lift and my gas mileage has not changed I now have over 5500 miles on the jeep
 

zdr

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Question...
When I drive my girl's JLU Willys 3.6 auto the avg mpg climbs rapidly compared to my JLU Rubicon 3.6 manual. I'm around 20.0-20.5 and hers is 20.5-21.0 but she usually drives with heavy acceleration.
Yesterday driving hers, mpg increased .5 miles in a short time and then driving mine the same way, it didn't increase at all.
I'm thinking if I drove the Willys consistently it would be close to 22.0 easily. Is this a gearing thing or transmission or both? Both are stock. Thanks!!
 

txj2go

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Question...
When I drive my girl's JLU Willys 3.6 auto the avg mpg climbs rapidly compared to my JLU Rubicon 3.6 manual. I'm around 20.0-20.5 and hers is 20.5-21.0 but she usually drives with heavy acceleration.
Yesterday driving hers, mpg increased .5 miles in a short time and then driving mine the same way, it didn't increase at all.
I'm thinking if I drove the Willys consistently it would be close to 22.0 easily. Is this a gearing thing or transmission or both? Both are stock. Thanks!!
could be differences in transmission, gearing, tires, weight, lift

automatic transmissions cause more losses in the drivetrain vs. manual
Rubicon has lower final drive gears but I don't know how the highest gears compare auto vs. manual
Rubicon has heavier, wider tires with more rolling resistance, and Rubicon has more lift so more of the tire area is exposed to cause wind resistance
I'm not sure about overall weight, but besides tires the Rubicon axles might be heavier
 
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