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V8 gas mileage?

Sarge

Well-known member
Just curious what others are getting with the V8 4x4 drivetrain.

After 2300 miles, I'm averaging an abysmal 12.9mpg according to the car, in mixed use driving. Car and Driver is getting 11mpg in their 6700 lbs, 700hp RAM TRX... Mine doesn't have the stop/start feature (wasn't available during production due to supply chain mismanagement) and I do use the remote start feature daily for 5-10 mins (very cold in Wyoming), but 12.9 still seems ridiculously bad in mixed town/highway use (55mph roads) compared to the 14/22 advertised. Even on my 1500 mile delivery road trip I only averaged 15mpg.
 

jeepdriver

Well-known member
Averaging 16 on my V8. My mix is probably more toward city driving. On long, highway only trips I'm able to easily get the 22 from teh window sticker.
Do you really mean Start/Stop? I didn't think that was offered on any V8 Grand Cherokees. There is Eco mode where it'll run on 4 cylinders. My vehicle does have that. It'll tell you in the cluster if it's working.
 

Deere78

Well-known member
The stupid start/stop crap doesn’t make much difference. It’s a gimmick to appease the CAFE standards for the government. Our v6 4wd isn’t getting the advertised mpg either. We are averaging 19.5 mpg in mostly highway driving. And it’s my wife that is doing most of the driving and she is light footed.
 

Sarge

Well-known member
Averaging 16 on my V8. My mix is probably more toward city driving. On long, highway only trips I'm able to easily get the 22 from teh window sticker.
Do you really mean Start/Stop? I didn't think that was offered on any V8 Grand Cherokees. There is Eco mode where it'll run on 4 cylinders. My vehicle does have that. It'll tell you in the cluster if it's working.
I haven't seen any buttons for 'eco mode' or any dash indications. How would I know?
 

jeepdriver

Well-known member
It's on one of the screens (WAY too many to keep track of). You'll see the neon green word ECO appear. Maybe when the center of the cluster is an analog speedometer?
I'll keep an eye out for it and let you know.
 

Sarge

Well-known member
It's on one of the screens (WAY too many to keep track of). You'll see the neon green word ECO appear. Maybe when the center of the cluster is an analog speedometer?
I'll keep an eye out for it and let you know.
In other cars I have, you can push a button on the dash to toggle between 'sport', 'normal', 'eco' etc. Usually softens throttle response, lowers suspension, deactivates cylinders, etc. I just haven't seen anything like that on mine.
 

RichSNJ

Well-known member
In other cars I have, you can push a button on the dash to toggle between 'sport', 'normal', 'eco' etc. Usually softens throttle response, lowers suspension, deactivates cylinders, etc. I just haven't seen anything like that on mine.
I think that every car fails to live up to stated MPG expectations. My 2019 Grand Cherokee V6 averages 17.3 or so. There is an Eco button, but it is a "normally on" feature that deactivates Eco mode when you push it. It also automatically deactivates when you go into Sport mode. I've never noticed any difference between eco on or off, and therefore I never use that button, but I do use the sport button sometimes.

I know that the L's don't have the Eco button, I assume they deleted it because it didn't really do anything on my old one. Depending on your Trim you should still have a Sport mode though...
 

WranglerDan

Active member
I think that every car fails to live up to stated MPG expectations. My 2019 Grand Cherokee V6 averages 17.3 or so. There is an Eco button, but it is a "normally on" feature that deactivates Eco mode when you push it. It also automatically deactivates when you go into Sport mode. I've never noticed any difference between eco on or off, and therefore I never use that button, but I do use the sport button sometimes.

I know that the L's don't have the Eco button, I assume they deleted it because it didn't really do anything on my old one. Depending on your Trim you should still have a Sport mode though...
Any idea what speed is used to determine the sticker MPG for highway? I wonder if it’s 65 or 70. Pretty sure that’s not a valid variable. Should be 10 MPH over the nation speed limit avg. Maybe someone on here can tell us the decrease % in MPG for every MPH over the speed used for the sticker.
 

Deere78

Well-known member
Any idea what speed is used to determine the sticker MPG for highway? I wonder if it’s 65 or 70. Pretty sure that’s not a valid variable. Should be 10 MPH over the nation speed limit avg. Maybe someone on here can tell us the decrease % in MPG for every MPH over the speed used for the sticker.
Our 2020 explorer easily achieved over the estimated mpg on the sticker. It’s happy place was 60 mph for non interstate driving. One would think these manufacturers would have stopped falsifying mpg figures after the VW scandal. A lot of consumers base their decision of a vehicle on claimed numbers. It seems of late these companies are rushing new models out without taking the time to properly test them and work the bugs out. With prices soaring and quality suffering the end result isn’t good for a brand. I left ford for this jeep after ford rushed the release of the new explorer. And here I am wondering if I just landed in the same situation again with jeep.
 

Deere78

Well-known member
Apparently the 'never buy a new model year' addage is still as true as ever.
Yeah I didn’t do my research on this one. I assumed a 2021 model in almost 2022 should have the kinks worked out. I wasn’t aware they didn’t start making them until June 2021. I just went to the gas station. Wife’s GCL said 138 miles to empty, had a just a hair over a quarter tank left according to the gauge and I put 17.8 gallons in it. So that seems to fall in line with the advertised fuel tank size. Maybe they aren’t all affected. I will continue to watch it as I am the sole person fueling the vehicle and report back.
 

Mike1597

Well-known member
Any idea what speed is used to determine the sticker MPG for highway? I wonder if it’s 65 or 70. Pretty sure that’s not a valid variable. Should be 10 MPH over the nation speed limit avg. Maybe someone on here can tell us the decrease % in MPG for every MPH over the speed used for the sticker.

EPA Highway test cycle
  • top speed 60 mph
  • Average speed 48.3 mph
  • Simulated distance 10.3 mi
 

WranglerDan

Active member

EPA Highway test cycle
  • top speed 60 mph
  • Average speed 48.3 mph
  • Simulated distance 10.3 mi
Thanks. Who drives 60 on the highway as a top speed? And now you know why the avg. never hits in the real world. I have to assume my avg. speed on the highway is considerably higher over 10.3 miles.
 

RichSNJ

Well-known member
I live in NJ and we don't pump our own gas, so I blissfully take the receipt from the attendant and crumple it up without ever looking at it, makes me happy on the inside. Been doing that since about 2005. I'm going to have to pay for it regardless, so why worry about it?
 

Nickrt

Well-known member
Whats interesting to me is that my Jeep seems to get ~15% worse mileage versus my 2019 Durango with the hemi. Shorter gear ratio may contribute…. Guessing that the durango trip computer was optimistic and hoping that the jeep’s is pessimisti. I need to check with real data to know.
 

miles5241

Member
Every time I hand calculate mine, the computer seems to be half glass empty and its always higher by hand by 1-2 MPG. also a half tank fills 14 gallons on a 23 gallon tank. Just not trusting the computer.
 

FatWL

Member
Stop and go driving i am getting 12 MPG. There is a huge difference on the highway - 65 MPH relatively flat i will get 20 MPG. My 21 V8 GC got 22 MPG on highway. I am still in break in......
 
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