Jeep 392 MPG / Gas Mileage thread

[rbarton]

You don't buy the Jeep 392 for gas mileage, but I'm a curious as to what everyone seems to be averaging? TFL posted a video showing 18.8mpg over 250 miles. That's impressive!

With the stock tires I was getting as much as 17mph with some mixed driving without any problem if I keep my foot out of it.

That quickly drops with some exuberant acceleration. (which is really hard not to do)

There has been a noticeable decrease of gas mileage when I got the 35" tires. I am doing well to get 14 at this point. I do think I could average 15 if the majority of miles are on the highway.

Still much more fun to drive than my previous 6cyl JL. And probably slightly better on gas mileage compared to the 6cyl.

 

[lacklustresoldier]

Just picked up my 392 yesterday from a dealer about 180 miles away, and I've put about 200 miles on it so far. After mostly smooth highway driving (foot has been light on the throttle for breaking in the HEMI) and a good hour or so of bumper to bumper traffic as I reached the city, I've averaged about 15mpg. I'm pleasantly surprised! Coming from a 2020 Toyota 4Runner TRD Pro, it's not as bad of an efficiency hit as I expected, though that may be more indicative of how inefficient the 4Runner's 4.0L V6 is.

 

[JimmyAZ392]

I've been averaging 17.7 mpg on my long trips and about 15.8 for city driving. This surprised me, because I'd be lucky to get 15 in my 2015 JKU.

900 miles 12.2

 

[Shortcut]

Maybe you can reach out to the companies customer service number on their website to ask. I'm interested in reading owners' experiences with "rocket fuel."

Thank you again BR. I did reach out to the Circle K on line customer service link shortly after reading your suggestion but still have not received a response and I check my junk and trash folders as well.

 

[Silver bullet]

I have 1400 miles on mine and with in town driving and if I keep my foot out off the floor boards I'm getting 15mpg avg per the computer. Over the weekend I did get 18.8mpg driving on roads with speed limits between 40 and 70 with some stop lights and on and off ramps. However it was only on a 44 mile round trip, but still very pleased with both numbers.

 

[Battle.Rattle]

I have 1400 miles on mine and with in town driving and if I keep my foot out off the floor boards I'm getting 15mpg avg per the computer. Over the weekend I did get 18.8mpg driving on roads with speed limits between 40 and 70 with some stop lights and on and off ramps. However it was only on a 44 mile round trip, but still very pleased with both numbers.

I have close to 6K miles and I'm still getting 15-16+mpg. With longer trips averaging around over 18.

 

[Shortcut]

I have 1400 miles on mine and with in town driving and if I keep my foot out off the floor boards I'm getting 15mpg avg per the computer. Over the weekend I did get 18.8mpg driving on roads with speed limits between 40 and 70 with some stop lights and on and off ramps. However it was only on a 44 mile round trip, but still very pleased with both numbers.

I'm getting close to 5K on my Jeep half of which was incurred by driving from Michigan to Southern Arizona. During my trip through several states (Indiana being one) after picking my Jeep up in Michigan I got almost 20 mpg on the highway/toll-roads and I attribute that to operating at near sea-level and the availability of 93 Octane fuel. Once one hits New Mexico & Westward, 91 octane fuel is the highest octane fuel that is available because of the higher altuitudes. Here in Arizona at about 4500 feet I am only getting 15 mpg on the highway and at best 11 mpg around town. The 37" tires I switched to aren't helping any as well.

 

[YukonCornelius]

The fuel nozzle is an unleaded sized nozzle but the pump does not have a label or any indication that it is actually unleaded like the other pumps at the station.

If the nozzle fit's, you can be pretty sure it's unleaded. A leaded pump is physically too big for an unleaded fuel door, which they have to be the correct size by law. Unfortunately, you "could" get it wrong backwards - unleaded into a leaded fuel door.

But if the local store doesn't know, again, you can be pretty darn sure it's unleaded - they would have to have a specialized license to carry unleaded, and most don't want to bother.

 

[Shortcut]

If the nozzle fit's, you can be pretty sure it's unleaded. A leaded pump is physically too big for an unleaded fuel door, which they have to be the correct size by law. Unfortunately, you "could" get it wrong backwards - unleaded into a leaded fuel door.

But if the local store doesn't know, again, you can be pretty darn sure it's unleaded - they would have to have a specialized license to carry unleaded, and most don't want to bother.

Thanks! I'm going to buy a small amount and check the color. I am told that leaded fuel is supposed to contain a red dye so I'll check to see if that color is present or not.

I also e-mailed the Circle K home office and inquired about this particular store's Racing fuel but have not received a response.

 

[redrubi]

My 392 now has roughly 900 miles on it and while traveling down the Garden State parkway I was averaging 16-18 mpg running BFG 315/70/17 KO2`s. The speedometer calibration and whatever else they do for the change in tire size
I did not verify it by using the amount of fuel used, I hope to do that this weekend
Around town is a rock steady 12-13 mpg due to the sound effects you get by opening up the exhaust system

 

[Tree]

12.5 around town, 14.7 Highway… IF I don’t drive like an asshole.
Smiles per gallon… priceless.
Worth every penny!

 

[redrubi]

12.5 around town, 14.7 Highway… IF I don’t drive like an asshole.
Smiles per gallon… priceless.
Worth every penny!

I know that it is just human interest to see what others are getting for fuel economy and anyone who buys a 392 is not worried about MPG. I just wish the fuel tank was a little bit bigger, my Raptor 3.7 tt 450 hp before tune was getting around 17 mpg on the highway and 12-13 around town . I had several different tunes for the Raptor, 91 octane and 93 octane were two that I had and my mpg stayed about the same but with the extra power to the wheels it was hard to keep the skinny pedal from hitting the floorboard, one of the good things was a 36 gal tank compared to the Rubicon`s 21 gal.
My 392 Rubicon weighs in at an estimated 5100 lbs and the Raptor weighed about 5600 lbs
Two totally different animals and both have their pluses and minuses BUT buth having high horsepower is good for the soul

 

[Tree]

I know that it is just human interest to see what others are getting for fuel economy and anyone who buys a 392 is not worried about MPG. I just wish the fuel tank was a little bit bigger, my Raptor 3.7 tt 450 hp before tune was getting around 17 mpg on the highway and 12-13 around town . I had several different tunes for the Raptor, 91 octane and 93 octane were two that I had and my mpg stayed about the same but with the extra power to the wheels it was hard to keep the skinny pedal from hitting the floorboard, one of the good things was a 36 gal tank compared to the Rubicon`s 21 gal.
My 392 Rubicon weighs in at an estimated 5100 lbs and the Raptor weighed about 5600 lbs
Two totally different animals and both have their pluses and minuses BUT buth having high horsepower is good for the soul

I 100% agree on a bigger gas tank!

 

[Smith392]

You don't buy the Jeep 392 for gas mileage, but I'm a curious as to what everyone seems to be averaging? TFL posted a video showing 18.8mpg over 250 miles. That's impressive!

I have 2,000 miles on stock tires. 18.5mpg average. Using 93 octane.

 

[Shortcut]

I have 2,000 miles on stock tires. 18.5mpg average.

I was getting great mileage until I switched to 37" tires.

 

[redrubi]

Has anyone put 100 octane or higher in yet? Obviously unleaded. I’m sitting on a 100 gallons of it and I’ve been really tempted to try. Performance yes but minimal, I really just love the smell.

Higher octane like 100 racing fuel by VP or Sunoco are not always the best to use in a stock motor. I had my Raptor on a dyno and I had a 91 octane program a 93 octane program and a auto adjust octane along with a trans tune. While fine tuning it with the 91 octane and then the 93 octane we jumped up to Sunoco 260 GT, 100 octane
We ended up losing power when we switched to the auto adjust octane program and the 100 octane fuel
There is a lot to read out there about this concerning all different octane levels. Here is a link to BOOSTane`s site
There is a lot of really good information on it especially regarding how much additive to use per gallons in your tank

BOOSTane - The Leaders in Octane Engineering

BOOSTane

boostane.com

 

[Yaak392]

You don't buy the Jeep 392 for gas mileage, but I'm a curious as to what everyone seems to be averaging? TFL posted a video showing 18.8mpg over 250 miles. That's impressive!

2500 miles and 18-20 mpg on Montana roads. It's 50 miles uphill to our home in the forest....
Can't stop smiling.

 

[Shortcut]

2500 miles and 18-20 mpg on Montana roads. It's 50 miles uphill to our home in the forest....
Can't stop smiling.

Are you running the stock 33" tires?

 

[Yaak392]

Are you running the stock 33" tires?

Yes, all stock except winch and sliders. The mpg is very pleasing. Especially considering the hilly roads.

 

[Shortcut]

Yes, all stock except winch and sliders. The mpg is very pleasing. Especially considering the hilly roads.

I hear ya! I was getting great milage 18-20 MPG at 650 feet elevation (Michigan), 93 octane and 33' stock tires. Brought it back here to Arizona and am now getting 11-13 MPG at 4500 feet, 91 octane and 37 in tires with a Tazer and Pedal Commander installed.