[Greg0130]

Inside of my Jeep Speedometer I keep the gas mileage displayed (you can turn that off if you want). The big green number in the middle is the instantaneous gas mileage and it can vary from almost nothing to 99MPG when you are coasting. The two smaller numbers are your range in miles (based on the amount of gas left in your tank and the average MPG as it remembers in white) and the current average MPG which you can reset after each tank, shown in blue. Remember to hit reset twice when you fillup. The first one doesn't seem to take. The second reset will take it back to 4.7mpg (go figure). The scale displays both instantaneous (green line) and average (blue with arrow). The more you drive, the more sense it will make.

 

[KLSWK214]

FWIW:

My '14 V6 4wd averaged 21.4 mpg over 125k miles (calculated thru the Fuelly app). About 30% of those miles longer trips (65-75mph), 70% urban driving with a mix of about 60% urban freeway (usually low speed commuting) and 40% stop-and-go local streets. I would average 19-20 on the urban driving and 24-26 on longer trips - a bit better than the EPA 17/24. Several times I averaged 28 mpg on long 500-mile trips.

My new '19 V6 4wd got 20.1 calculated on the first tank (vs. 20.4 on the EVIC) and is showing 20.8 on the EVIC under the same conditions on the almost-gone 2nd tank. All commuting miles. On that limited data I'm expecting similar long-term results to my '14. I'm hoping for a little better than my '14 since the EPA rating is better at 18/25 in my '19.

I run on cruise as much as I can on longer trips, and even when I can on urban freeways. I run 87 Octane fuel, and about 38psi in the tires. I leave it in Eco mode since I didn't really notice much difference in daily driving. Not much hot-rodding other than freeway merges and highway passing.

 

[The Wizard]

I never knew there was a difference in winter and summer fuels - the things we learn.

Gasoline evaporates more in higher temperatures so refineries must make a summer blend and a winter blend to meet regulations regarding fuel evaporating into the atmosphere. The volatility or tendency to evaporate is called its Reid Vapor Pressure (RVP) rating. The lower the RVP rating, the lower its tendency to evaporate. Summer gas has an RVP of about 7.9 while winter gas is around 10. The difference is mostly the removal of butane (a petroleum product that evaporates relatively easily) from the summer blend. Butane is cheap and plentiful so using less of it for the summer blend is part of the reason gas prices go up in the spring and back down in the fall. Its also the reason for better mileage in summer... butane has less energy than pure gasoline so less butane/more gas means better mileage. That's the same as ethanol... pure gas has more energy than ethanol so you get better mileage with pure gas than with E10 or E15.

 

[Kaldir]

I bought my 2015 WK2 with the 3.6 about 5 months ago, and was also surprised at the MPG. I get about 18.5 (paper and pen method) IF I use 93 NON-Ethanol fuel. If I use 83, its about 17. I do 30% city driving, give or take. On a highway run I will get 24 easy, if I stay at or under 75 MPH.

 

[lorimand]

FWIW:

My '14 V6 4wd averaged 21.4 mpg over 125k miles (calculated thru the Fuelly app). About 30% of those miles longer trips (65-75mph), 70% urban driving with a mix of about 60% urban freeway (usually low speed commuting) and 40% stop-and-go local streets. I would average 19-20 on the urban driving and 24-26 on longer trips - a bit better than the EPA 17/24. Several times I averaged 28 mpg on long 500-mile trips.

My new '19 V6 4wd got 20.1 calculated on the first tank (vs. 20.4 on the EVIC) and is showing 20.8 on the EVIC under the same conditions on the almost-gone 2nd tank. All commuting miles. On that limited data I'm expecting similar long-term results to my '14. I'm hoping for a little better than my '14 since the EPA rating is better at 18/25 in my '19.

I run on cruise as much as I can on longer trips, and even when I can on urban freeways. I run 87 Octane fuel, and about 38psi in the tires. I leave it in Eco mode since I didn't really notice much difference in daily driving. Not much hot-rodding other than freeway merges and highway passing.

So it sees you are doing much better than I am out of the gate.

 

[moparado]

Not to throw a crobar in all of this but a few days ago i accidentally fueled up with 88 Octane Flex Fuel. I normally use regular unleaded 87 Octane.

Could be coincidence or Summer vs. Winter transition but the mpg per the lie-o-meter is noticeably better about 2 mpg better.

 

[BubbaATL]

I bet it's winter --> summer. Mine seems to have gotten better in the last few weeks also, although I haven't been paying close attention.

 

[Mongo53]

Everything mentioned is good advice. Perhaps it will improve.

Tire Pressure, higher tire pressure produces better mileage, lower tire pressure reduces it. Keep in mind, as you drive your tires heat up and increase the pressure in the tire, the pressure is measured when the tires are cold. So if you're reading tire pressure after driving a while, and it says 40PSI, that might actually be the Door Jamb recommended 36PSI while cold, that the factory sets and the dealership sets also. If you increase the tire pressure a few psi, that might make the slightest bit of improvement.

Don't forget the Mileage is determined by the EPA in special tests, your actually mileage may vary. They have improved the test over the years to be much closer to the actual mileage the average person would get. But the thing is, your city driving may be much worse than the test. If you're using start/stop, that might offset excessive idle time at lights. But there are plenty of city driving that consume far more fuel than the EPA test and most drivers and your mileage could be down because of that.

And in case you didn't know, using the remote start often to warm-up the motor and run the HVAC before getting in the vehicle to drive will drop your mileage, a noticeable amount.

 

[The Wizard]

Also, although increasing tire pressure can contribute to slightly better mileage, it can also contribute to accelerated tire wear in the center of the tread.

 

[Doppleganger]

Tire pressure is a long-term experiment for me. Maximum pressure I can use while getting the most even treadwear. Honestly, I'd rather wear out the middles faster than the edges, though.

 

[moparado]

I bet it's winter --> summer. Mine seems to have gotten better in the last few weeks also, although I haven't been paying close attention.

Yeah you're probably right.
I'll find out next Winter. Can hardly wait-not!

 

[jeep12joe]

I find that with all my vehicles, using 93 octane gas gets me better mpg's and more miles to a tank.

Please don't do this, it is a total wasted of your money. Higher octane gas doesn't do anything for engines designed for regular. High octane is designed to resist premature combustion in engines with high compression, which you do not need to worry about. Not to mention it will cost you about $0.60 per gallon more than regular.

 

[garyhill]

I have the 3.6l, drive 80 on the interstate and 65 in the 55 zones in the winding country roads. I never get less.than 23mpg, that's calculated, not off the computer (miles driven÷gallons refilled)

 

[Russinator]

This was my problem.

 

[add1cted2]

I have an '18 Trailhawk with a HEMI (man it never gets old saying that) and I get 14-15MPG according to the trip computer. My daily commute is 15 miles each way sitting on the 405 fwy.

Also, I'm running 33 PSI (cold)

 

[TFLG]

I'm pretty shocked at how bad the mileage on my V6 2020 trailhawk is vs what the sticker said. I just did a 370 mile all hwy drive from St George Utah to SoCal and only averaged 19.4 mpg (calculated, 19.1 gallons), the trip computer said it was 20.1. Set the cruise at 80 and did it pretty much the entire way home so I was expecting pretty good results. That's pretty bad considering it's supposed to be closer to 25mpg on the hwy. Around town I'm only getting about 15. And I drive this like an old lady around town (my wife on the other hand...) My Mustang GT does better than this thing. It's only got 2000 miles so hoping it improves as it breaks in but so far I'm not impressed with the mileage.

 

[Kaldir]

I'm pretty shocked at how bad the mileage on my V6 2020 trailhawk is vs what the sticker said. I just did a 370 mile all hwy drive from St George Utah to SoCal and only averaged 19.4 mpg (calculated, 19.1 gallons), the trip computer said it was 20.1. Set the cruise at 80 and did it pretty much the entire way home so I was expecting pretty good results. That's pretty bad considering it's supposed to be closer to 25mpg on the hwy. Around town I'm only getting about 15. And I drive this like an old lady around town (my wife on the other hand...) My Mustang GT does better than this thing. It's only got 2000 miles so hoping it improves as it breaks in but so far I'm not impressed with the mileage.

I've personally noticed any speed above 75 will get really shit MPG. 75 MPH has been the sweet spot for me on long drives.

Also, if you can get non-ethonal fuel, use that for a long trip. You will get much better MPG with non-ethanol.

 

[KLSWK214]

FWIW, I'm on my 2nd V6 WK2 (14 and 19) and over 155k combined miles I have a lifetime average over 21 based on the Fuelly app. I average 19-20 around town and 24-25 on the road. (When my wife drives she averages around 16-17 in the same vehicle - leadfoot.). I drive between AZ and CO quite a bit to visit family and have gotten as high as 28-29 on several of those trips. I'm usually not pushing 80, though, probably closer to 65mph driving average due to road type.

 

[TFLG]

I've personally noticed any speed above 75 will get really shit MPG. 75 MPH has been the sweet spot for me on long drives.

Also, if you can get non-ethonal fuel, use that for a long trip. You will get much better MPG with non-ethanol.

Driving 75 on the I-15 would likely get me shot or run over by an Semi lol. even at 80 I was one of the slower cars on that road.

 

[KLSWK214]

I hear you. Different driving across the Res in northern AZ (80-85 might get me thrown into jail, tribal cops have no sense of humor) and the mountains in SW CO (you're lucky to get 25 on the Million Dollar Highway)!