Why are the 2021's rated at higher mpg's than the 2020 model?

DadJokes

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You have a Sahara? Going up one inch in tire size makes that much difference?
Yes, a Sahara. I haven’t upsized tires yet. Still 32’s. Only suspension mods are a Rubicon suspension giving a (prior to winch/bumper) 1” boost up front and .750” in the back over stock.





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blnewt

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I agree. Takeoff suspension here and now an aftermarket bumper and winch. I think I’m about .5mpg down so far. I’ll be going 33’s and I think that’s going to be the most considerable drag on fuel economy.

I’m aware ours not calculated mileage though. I’m not sure how far off the worst calculated mpg has differed from the onboard display. Calculated or not, if we’re all using the same tool to measure, it should be good for comparing efficiency amongst each other. My highest average ever has shown 26.9mpg. Some claim higher.
Damn,
Daniel you have that huge 21 gal tank too, some people catch all the breaks, looks like you're going 150 miles further per tank than us puny 17 gal 2dr owners running the V6.
 

DadJokes

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Damn,
Daniel you have that huge 21 gal tank too, some people catch all the breaks, looks like you're going 150 miles further per tank than us puny 17 gal 2dr owners running the V6.
To clarify, that’s exclusively highway. I think I’ve gotten down into the low 20’s in our normal city/hwy mix. ~21-22mpg avg
 

blnewt

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To clarify, that’s exclusively highway. I think I’ve gotten down into the low 20’s in our normal city/hwy mix. ~21-22mpg avg
But not driving on the hwy is where all the fun is, hwy driving is all about the mpg lol.
#you'restillwinning
 

BillGalway

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This question is specific to the JLU Sport family equipped w/2.0L . The 2020 was rated at 21/22 mpg's but the 2021 units showing up on the lots with same spec's are showing 21/24. If this has been covered my apologies. Thanks

2021

2020
I can’t really complain about gas mileage as I got 31 mpg On the highway over 430 miles. Never though I would see numbers like this from my Jeep JL 2.0 4 cylinder turbo
9A1E4468-9CA9-4089-8F7C-631A2677A3B6.jpeg
 

Dusty

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You have a Sahara? Going up one inch in tire size makes that much difference?
Increasing the tire diameter has an adverse effect on MPG due to the higher aerodynamic drag (raised vehicles create a lot more wind resistance) and the higher reciprocating weight of the larger tires. If the tires are wider they generate more drag, too.
 

aldo98229

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On my prior Wranglers: going to 33” tires took 1 MPG; going to 35” took 2 MPG.

My JKURs with 35” tires averaged 16.5 - 17.0 MPG; no matter how I drove. In stock form they were supposed to average 18-19 MPG.

My JL Sahara is averaging 18 MPG, in mostly city driving with 33” tires. Can’t really complain.
 

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I average 24.5 … seems accurate to me.
 

jdubya421

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Increasing the tire diameter has an adverse effect on MPG due to the higher aerodynamic drag (raised vehicles create a lot more wind resistance) and the higher reciprocating weight of the larger tires. If the tires are wider they generate more drag, too.
I was blown away that going from 33s to 37s didn't kill my MPG (with the 3.6). I went from like 22 average to 19.5 average on the highway. I haven't even re-geared. I am assuming that when my lift goes on and the Jeep gets even taller it will get worse.
 

aldo98229

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Increasing the tire diameter has an adverse effect on MPG due to the higher aerodynamic drag (raised vehicles create a lot more wind resistance) and the higher reciprocating weight of the larger tires. If the tires are wider they generate more drag, too.
Yes. And let’s not forget that a 35” MT can weigh twice as much as a 32” AT.

Stock tires weigh around 45 lbs each; 35” MTs can weigh anywhere between 70 and 90 lbs each. Times 5...that’s an extra 125 to 225 lbs of dead weight the Jeep is carrying around all the time. If you pick some heavy aftermarket wheels, it’s even worse.
 

entropy

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That is incredibly impressive given that you have also added rubi takeoff suspension. An actual Highway range of well over 550 miles is terrific! Congrats!
I get 26~27 highway on my 3.6 2 door sport S with rubicon suspension. Stock AT tires.
 

Dusty

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I live at 4,600' and my 2.0T gets about 23-24 mpg. I use cruise control nearly always and am running BFG 255/75x17 (32.5"). The turbo makes driving in the mountains (Sierra) a pleasure. Soon, I'm adding a Rubi take off suspension which will give a 1 - 1.5" lift. I'll run a route before and after the suspension and report back with the change in MPG.
 

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Yes. And let’s not forget that a 35” MT can weigh twice as much as a 32” AT.

Stock tires weigh around 45 lbs each; 35” MTs can weigh anywhere between 70 and 90 lbs each. Times 5...that’s an extra 125 to 225 lbs of dead weight the Jeep is carrying around all the time. If you pick some heavy aftermarket wheels, it’s even worse.
Enkei says (allegedly) every pound of unsprung weight is equal to 20lbs of sprung weight. A more conservative calculation puts it closer to 1.5. Even still, that's substantial not counting the rotational mass.
 

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That's the best response I've seen in a good while.
 

rubileon

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I can’t really complain about gas mileage as I got 31 mpg On the highway over 430 miles. Never though I would see numbers like this from my Jeep JL 2.0 4 cylinder turbo
9A1E4468-9CA9-4089-8F7C-631A2677A3B6.jpeg
31MPG at 25mph? I haven't gone that slow but the 3.6 could get 31MPG at 40MPH in the JK and at 60MPH in the JL (both auto)
 

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