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I want to share my journey.

As some of you know, I’ve been struggling with extremely poor fuel economy numbers since last fall. As the weather got cold, my MPG dropped to 12-13 MPG around town; 15 MPG on the freeway.

For reference, my 2018 Sahara is a V6, automatic with a dealer-installed Mopar lift and 35-inch ATs.

Regearing

Due to the tall 3.45 gearing and the large tires, my auto wasn’t shifting past 6th gear. So last February I took a 1,000-mile road trip from WA to UT to have the gears swapped to 4.88.

My MPG getting there was a pathetic 12.7!!!

The gear swap went swimmingly and the Jeep regained full use of the 8-speed automatic. I really like how the Jeep drives and feels now.

Refueling in UT and WY

More interestingly, though, I noticed my fuel consumption improve significantly the moment I started pumping gasoline in Utah, jumping to 18 MPG on the first tank.

On the way back, with the new gearing, full use of the automatic transmission, and returning to our shitty west coast gasoline blend, I averaged 15.7 MPG. An improvement of 3 MPG.

However, driving around town over the past couple months my average has been going back down: it was 13.7 MPG early this week.

NO ETHANOL gasoline

I found a gas station at a nearby Indian reservation that sells 92 octane gasoline with NO ETHANOL. As an experiment I filled up the tank two days ago: my average over the first 50 miles appears to have improved by 3+ MPG to 17; mostly in city driving. If this holds, I should be averaging 18-19 MPG on the freeway. Similar to what I was getting in UT and WY.

I’d be very happy with that.

Moral of the story

If you are frustrated with your JL’s low MPG and are running out of ideas: see if you can find a gas station near you that sells NO ETHANOL gasoline and give it shot. My bet is you will see a dramatic improvement in your MPG.
 

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Agreed. The gas station that sells no ethanol is 18 miles away. But I can easily justify the 36-mile round trip if I can squeeze an additional 100 miles out of a tankful!
 

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2015 JK Willys 2 Door
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The 2.0T in our 2 door JL sport is averaging 27.5mpg!!!

Sure it has highway tires and the nearest stop light is 45 miles away. However, we aren't easy on the throttle and have to punch it just to get out on to the 2 lane 55mph highway.
 

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Discussion Starter · #7 ·
My 4.0 YJ get's average 15. Wife's camry gets average 33-35. It's about smiles per gallon not miles per gallon. I smile a lot more driving my Jeep than her camry.
Yeah, well, I find it hard to keep smiling when I’m getting 12 MPG...! :LOL:

Don’t get me wrong, I don’t mind getting 9 MPG in 4L on the trails, but 12 MPG to go to Trader Joe’s...c’mon...
 

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Nice suggestion and great info. BUT ... It is a non-issue with those of us who have the 2.0 because it requires (well ... so they say) 91 or better octane. And there aren't any 91 octane pumps that I have seen in our area that are non-ethanol.

Mine is getting 21-23 on the highway and I can live with that.
 

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We are lucky at least in that regard here in Alaska, Aldo, as it has been years since any ethanol-containing gasoline has been sold here.

I remember one time, though, back in the late 90s, when gasohol was sold here, that I filled up at a station in Anchorage, only to literally and visibly watch my gas gauge fall as I drove out of town. Instead of maybe getting my usual 350 miles per tank, I only got 120 miles out of that particularly fillup. What I think happened was that due to some crazy accident, the station's tank had gotten filled with pure ethanol, and that was what I then filled up with as well. I've never had anything like that happen before or since.
 

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However, driving around town over the past couple months my average has been going back down: it was 13.7 MPG early this week.

NO ETHANOL gasoline

I found a gas station at a nearby Indian reservation that sells 92 octane gasoline with NO ETHANOL. As an experiment I filled up the tank two days ago: my average over the first 50 miles appears to have improved by 3+ MPG to 17; mostly in city driving. If this holds, I should be averaging 18-19 MPG on the freeway. Similar to what I was getting in UT and WY.
I think you need to do more testing than 50 miles, or at least E10 has about 4% less energy per gallon than pure gasoline so you should see a reduction on that order, not the 24% you saw above. Whatever is causing the other 20% isn't ethanol alone.
 

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Nice suggestion and great info. BUT ... It is a non-issue with those of us who have the 2.0 because it requires (well ... so they say) 91 or better octane. And there aren't any 91 octane pumps that I have seen in our area that are non-ethanol.

Mine is getting 21-23 on the highway and I can live with that.
We run our 2.0's on 87, no issues.
 

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We run our 2.0's on 87, no issues.
Glad you're happy. And I know the manual says that 87 is OK. It also says that 91 is recommended for "optimum performance". Whether that means better mileage or not I can't say because I haven't compared the difference in the real world. Since I usually don't drive but 200-250 miles a month the price difference isn't a factor for me personally. I'd rather have the "optimal performance" than the small money savings I'd get with the lower octane.
 

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Yeah, well, I find it hard to keep smiling when I’m getting 12 MPG...! :LOL:

Don’t get me wrong, I don’t mind getting 9 MPG in 4L on the trails, but 12 MPG to go to Trader Joe’s...c’mon...
And that, my friend, is why we NEED “2 buck Chuck!” Sorry, “3 buck chuck!”
Troy
 

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2021 Wrangler Sport - Firecracker Red
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The 2.0T in our 2 door JL sport is averaging 27.5mpg!!!

Sure it has highway tires and the nearest stop light is 45 miles away. However, we aren't easy on the throttle and have to punch it just to get out on to the 2 lane 55mph highway.
Same here...stock 2 door 2.0T AT and over 27 mpg avg. I keep 93 in it. Could not be happier...
 

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08 JK Sahara 3.8, 4wd, AT
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Stock 08 Sahara 3.8 180000+ miles. I get 18 - 19 normal driving, 20 on the interstate. But, I don't get in much traffic rural Georgia.
 
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Here's what I've averaged with the last 4 Jeeps. All pretty well stock.

'13 JK, V6, manual: 17mpg
'14 JKU, V6, auto: 14mpg
'20 JLUR, Ecodiesel, auto: 27mpg
'21 JL, V6, manual: 20mpg
Those are interesting and useful numbers to see, JPCannon, as presumably your driving habits have been the same in those various Jeeps.

I still always have to point out, though, that mpg figures by themselves are almost meaningless without also knowing the driving habits of the driver, whether they drive mostly city or mostly highway, the kind of terrain in which they drive (hilly or mountainous vs. flat), etc. --- particularly when it comes to speed, with such an un-aerodynamic vehicle as a Jeep Wrangler.

I'm continually struck by the excessively and dangerously high speeds that so many of you in the Lower 48 claim to routinely drive, 75 or 80 mph or even higher. Driving at such speeds IS going to significantly reduce your fuel economy, especially in a Jeep.
 
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