2021 Rubicon EcoDiesel EPA rated MPG drops (per window sticker)

[rickinAZ]

Hell I average almost 23 and usually pull a small trailer, up & down 11% grade every time I leave the house. I am just over 10K.

The 11% grade is an interesting variable. I used to live at 8,200’ and commuted to the Denver foothills every day. On the way to work, I went for miles without touching the gas while the instant mpg read 99 mpg. On the way home I’d get single digits going up the hill. I always thought that the two way average ended up being better that I could get on flat land.

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[JLURD]

Unfortunately none of those reports are trustworthy, which is why we have to turn to Fuelly.com to get the truth because those hand calculations take the guesswork out. And what we're seeing so far after nearly 40,000 miles of combined real-world data is a MPG figure around 20.7 MPG. This lines up pretty well with the 21 MPG I'm averaging also.

That's nowhere close to the 24 on the window sticker.

Yea I hand calculate mine from a topped off filler neck and average 23mpg +/- 1mpg depending on average speed...with 37s, heavy beadlocks, a 2.75” lift, a roof rack, and 250-300lbs of gear/mods. 20.7 is ridiculous unless the sample vehicles are cruising at 75+mph with serious mods or towing.

 

[WXman]

Well maybe you guys should buy lotto tickets. :D The average person isn't seeing anywhere near those numbers, and neither am I.

Which takes us back to the original post...that Jeep is adjusting the window sticker MPG downward to be more accurate, and they probably need to go down even more.

 

[SolarWizard]

I’ve driven all the way across Arizona in a JLRD on 37s with stock gearing showing 28-29 on the dash with a corrected speedo

full tank in Yuma, AZ refueled in the last town in AZ heading toward Gallup (no idea the name)
dash was showing 28 mile range. We had a 3 gallon rotopsx on the back so it was a purposeful experiment. That’s about 440 miles and includes a climb from sea level for 6500 feet and back down

my friend with the Jeep averages about 19 because it’s fun to hammer the throttle all the time.
before I got myTesla i had a Prius Plug in. I mashed the throttle a lot and averaged about 39 mpg over the life of the vehicle. That’s well below the monroney Number.
what I’m getting at is fully doesn’t take into account the throttle discipline on fun vehicles. The mustangs numbers are strangely below stated. Doesn’t mean they CANT get the mpg. It just means people aren’t trying

 

[JLURD]

Well maybe you guys should buy lotto tickets. :D The average person isn't seeing anywhere near those numbers, and neither am I.

Which takes us back to the original post...that Jeep is adjusting the window sticker MPG downward to be more accurate, and they probably need to go down even more.

You’re comparing a company and government agency tasked with reporting bone-stock fuel economy figures to a sample of the most heavily modified vehicle in America with zero description of what those modifications are within the sample, let alone the average speeds driven. Apples and oranges much? That’s actually not even a good metaphor for what you’re doing...it’s more like comparing apples to some fruit that resembles an orange but which we don’t really know the true nature of its composition.

 

[imjester77]

The speed limit in the area you are driving plays a ton as to what your fuel economy will be. I live here in Texas (South East) and it is FLAT! At sea level and Speed limit is 75MPH. My Highway average with just a 2.5" lift on stock 33's in my Rubicon is at 26. My around town average is at 19.

Now I did a small test to see where the optimal fuel economy was and here is my findings:
@80 25-26 MPG
@75 26 MPG
@70 26-27 MPG
@65 26-27 MPG
@60 28 MPG
@55 28 MPG
@50 30 MPG (Maybe the wind was to my back not sure)
@45 33 MPG
@ 35 37MPG!

I was really Really board and figured since the kiddos wanted a drive in the Jeep (Just back from the shop after 2 months) I would take some back country roads and do some testing.

This is not scientific and done with 36 PSI in all 4 tires, a full tank of Fuel and about 320#'s of people (me, wife, 3 kids). Soft top was up and AC on. I used cruise control on all runs and went about 15 miles on each test. The dealer asked me to put miles on the jeep to test it anyways so why not be productive.

the tests of 60-80 were done on the highway. all others were country roads.

Hope this helps.

 

[wrc777]

A new headscratcher.

I rented a gladiator sport with 3.6 and got 25-26 mpg highway. I would expect 17-18 mpg on the same trip in our jlur with same engine and transmission.

 

[Buckshot184]

The fuelly numbers do appear to be much lower than i have been getting. I’m at 4K miles, commute about 50 miles per days on mostly highway and have been getting 26-27 mpg hand calculated on a ‘20 JLUD Sahara. And I haven’t had a single tank get less than 25 mpg

 

[Killdozer]

Speeds ranged from slow small town 40 to highway 70 plus. Half the trip was through hilly terrain and the other half mostly flat. These are smaller base sport tires so I'm sure that helps. In the end it was still average over 30. These numbers will drop soon once a lift and tires are installed.

 

[huntb]

These EcoDiesel engines love cruising at low RPMs and I actually increased my fuel economy by a couple MPG on my JGCED by putting tires 2" taller than stock on it. It brought the cruising RPMs on the highway down into the sweet spot. FCA should be putting taller gears on the ED vehicles if they want to get their EPA numbers up

 

[Wrangler man]

Virtually none of us bought these diesels exclusively for the fuel economy, but if I had, I’d feel like the victim of a bail & switch. They so touted the mileage and then very quietly it went down 10%. I can picture a Jeep executive studying his fingernails and saying “ oh...did the rating go down? I really hadn’t noticed”

Come on Jeep, man up. We’ll still love you

I think it's about cya remember with the feds did to Volkswagen. Wranglers are the most modified vehicle on the road every mod will vary the mpg very few people never change a thing.

 

[Ruby Clatterbox]

I’ve been driving a ‘20 diesel all week and averaging 26-27

Ditto. I actually get better mileage on long runs around town 50ish mph than on the interstate. I've seen a solid 28-29 (on the dash, not verified) while interstate driving at 70-75 brings it down to around 26-27.

 

[Whaler27]

We love our ecodiesel Grand Cherokee, but we love it less since required reflash significantly reduced power AND fuel economy. The reflash was done last spring as one of the conditions of the FCA class action lawsuit settlement.

Last week we got another notice from FCA telling us we needed to get another reflash. We’re worried that will mean another drop in performance and fuel economy, sp we’re dragging our feet.

Maybe the original EPA testing on the new diesels was done before FCA landed on its final tune to satisfy government requirements?

 

[WXman]

We love our ecodiesel Grand Cherokee, but we love it less since required reflash significantly reduced power AND fuel economy. The reflash was done last spring as one of the conditions of the FCA class action lawsuit settlement.

Last week we got another notice from FCA telling us we needed to get another reflash. We’re worried that will mean another drop in performance and fuel economy, sp we’re dragging our feet.

Maybe the original EPA testing on the new diesels was done before FCA landed on its final tune to satisfy government requirements?

Sounds like yours is a perfect candidate for a GDE tune. You'll be able to keep your emissions equipment and get back everything you lost in the dealership reflash and even more. No, it's not cheap but the added MPG and power restoration would make it worth it.

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