Help me understand what's going on with my MPG

[Jeeperjamie]

500 miles to Alabama, I averaged between 16-17. That was with keep speeds between 70-75 most of the time. Maybe I don’t understand the shift points, but 70-75 should almost always be in 8th gear, with the exception of steep grades. The difference in rpms is only around 500 when doing 75 in 7th and 8th gear. Even if my speedo was off by 2-4 mph, that shouldn’t make a difference at that high of a speed. Right? This questions also for @Jeeperjamie

2-4 mph could most definitely have a affect on shift points and is probably why yours is staying in 7th for most of the time. I don't know the math or anything on how much of difference but in my JKU and the JT, when I added larger tires my shift points were way off. In the JK it was hanging in gears and almost never went into over drive. That's going from a 33 to a 35 and with speedo off by 3 mph. In the JT going from the stock 32 to 35 had my speedo off by 6 mph which resulted in it never going to 8th gear and riding in 6th gear for a lot of the time. I only ran it like that for maybe a week or so before recalibrating and once I did the shift points were spot on back to stock. I downloaded a video for your reference as well as anyone elses if they are curious as to how one should probably drive on the interstate. This is a 4 minute stretch between Mallard Creek Pkwy and Kannapolis Pkwy right by Concord Mills on I-85. It's pretty flat with one incline and then it flattens out and starts down hill. Hopefully this helps.

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[Jaydebe]

500 miles to Alabama, I averaged between 16-17. That was with keep speeds between 70-75 most of the time. Maybe I don’t understand the shift points, but 70-75 should almost always be in 8th gear, with the exception of steep grades. The difference in rpms is only around 500 when doing 75 in 7th and 8th gear. Even if my speedo was off by 2-4 mph, that shouldn’t make a difference at that high of a speed. Right? This questions also for @Jeeperjamie

Yeah, 1 gear seemed to make a difference for sure, RPMS aside.
For every gear down it seems to drop 1.5 ish mpg.

That said, I often used the e-shift crossing the country with the trailer. The truck would roll about 2800-3000 rpms in 5 or 6th gear in full-auto, using the manual I could push it up a gear.

It saved some mpgs, but over the very, very long haul. It turned out to be a game than do anything. LOL

The trucks shift points IMO are spot on for keeping it from hunting all the time; and while it may seem to waste fuel not moving to the next gear, the law of avg's really creeps in here and it ended up mostly a wash.

I'd say that when I would manually shift, I would eek out maybe 1 mpg better (13-14mpgs) ; but had to shift down more often and it would suck down fuel (drop to 9-10).

If I just let it do what it does, it would be 12ish, then downshift when needed, but maybe drop to 10-11 mpg.

At the end of the day, I may have squeaked out mid-12's and in full auto, maybe low-12's.
Again, it was more about learning a bit and also keeping occupied on 12+ hr drive days.

Also, watch you foot on the gas pedal! If you just into "instant mpg" mode and watch it; it's real easy to add or subtract 1-2 mpg by adj, your foot pressure, but seemingly not effecting how the truck drives. Really, no different than a standard cable actuated accelerator; you learn to feather the pedal some. And, shoes make a difference! A sneaker vs a boot IMO offers a completely different feedback to what the pedal is doing.

 

[Barbed_FWTX]

Mine must be broken. Bone stock JTR. I can scarcely get 15 mpg out of it. Afraid if I add a lift and bigger tires I'll drop down to 12-13. Haven't been hitting the highway at all during this covid nonsense, though, and live in a very hilly town, so that might be all it is. If I saw 18 mpg I'd just about die of happiness.

Same here, I go from high 14s up to low 16s depending on how much highway driving I do. Hoping to start my official build process next year around this time and I’m worried about the mpg plummet. Wanting to do 2.5-4.5 inch lift with 35-37 not 100% which combo yet. And hopefully add a CAI and the Corsa dump exhaust too.

 

[Jeeperjamie]

Same here, I go from high 14s up to low 16s depending on how much highway driving I do. Hoping to start my official build process next year around this time and I’m worried about the mpg plummet. Wanting to do 2.5-4.5 inch lift with 35-37 not 100% which combo yet. And hopefully add a CAI and the Corsa dump exhaust too.

2.5" lift and 35's with rugged ridge front bumper and Apex 12000lb winch and I'm getting 19+ out of mine.

 

[Alabama Mud Machine]

I just thought about something..............One of those "I could'a had a V8!" moments...

What grade of fuel is everybody running? I'm running 87 because I saw a JTR dyno run video where the guy ran 87 and 93, and he gained pretty much nothing with the 93 octane... So basically his results proved that if you're running anything over 87 you're throwing money away. Those of you getting better than 15-16 MPG's on oversize (larger than stock) tires, what octane or type of fuel are you running? This might help us figure out what's going on with why some are getting really high MPG's and some are getting bad.

 

[Jeepnoob34]

2-4 mph could most definitely have a affect on shift points and is probably why yours is staying in 7th for most of the time. I don't know the math or anything on how much of difference but in my JKU and the JT, when I added larger tires my shift points were way off. In the JK it was hanging in gears and almost never went into over drive. That's going from a 33 to a 35 and with speedo off by 3 mph. In the JT going from the stock 32 to 35 had my speedo off by 6 mph which resulted in it never going to 8th gear and riding in 6th gear for a lot of the time. I only ran it like that for maybe a week or so before recalibrating and once I did the shift points were spot on back to stock. I downloaded a video for your reference as well as anyone elses if they are curious as to how one should probably drive on the interstate. This is a 4 minute stretch between Mallard Creek Pkwy and Kannapolis Pkwy right by Concord Mills on I-85. It's pretty flat with one incline and then it flattens out and starts down hill. Hopefully this helps.

That’s about how mine drives. The incline didn’t look like much but I see your in 7th. Once it flattens out, mine goes to 8th also.

 

[Jeeperjamie]

I just thought about something..............One of those "I could'a had a V8!" moments...

What grade of fuel is everybody running? I'm running 87 because I saw a JTR dyno run video where the guy ran 87 and 93, and he gained pretty much nothing with the 93 octane... So basically his results proved that if you're running anything over 87 you're throwing money away. Those of you getting better than 15-16 MPG's on oversize (larger than stock) tires, what octane or type of fuel are you running? This might help us figure out what's going on with why some are getting really high MPG's and some are getting bad.

87 octane because I think I watched that same video

 

[Jeeperjamie]

That’s about how mine drives. The incline didn’t look like much but I see your in 7th. Once it flattens out, mine goes to 8th also.

That's about what you should expect then. The incline doesn't look bad, but it's actually a ok incline, can't really tell because it appears more flat but it's about 90ft of elevation gain from bridge to bridge, which is only about 3/4 of a mile, it's just not a steep climb but gradual climb. Sorry to be using runners terminology , just the runner in me coming out.

 

[donaldus]

So I've been real pleased with the gas mileage I've been getting since going to 315 70 17 BFG KO2s. Ran the 35 12.5 17 BFGs on my 2010 JKU with 3:73 gears and built and never saw over 15MPGs. So with my JT when I switch to the taller tire I removed the section leading up to the fender on the Foglight covers. I've been getting between 18-18.5 MPGs and I was happy with that.

Well last week I removed the front bumper and installed a Rugged Ridge full width spartan Bumper and a Badlands Apex 12000lb winch. Now I was expecting a drop in MPGs because of the weight and was completely going to be fine if it dropped down to even 17 MPGs. Now as of today on my way home I'm getting 19.1 MPGs in JT and nothing driving habits wise has changed or any of my routes. It's been warmer but other than that nothing else has changed. Does aerodynamics make that much of a difference because I feel like because the full width bumper closed that gap up again it caused the jeep to not have as much wind resistance. I can actually feel a difference with the wind blowing. If this is how it's going to be then I'm freaking super happy with my decision to by this truck. Any thoughts on anything else that could contribute to the MPGs going up.

Took both of these today. Took one when I hit 19 and the other about 20 minutes later when it went to 19.1. Can't believe it

I was getting around 17 off the showroom floor. Put on the Banks intake; up to 18...MBRP performance exhaust/ZMAX...getting 20.5 on average (really watching my lead foot). My normal drive is on I20 @ 75 mph, cruise control on. Around town I drive my old Beetle. The 8 speed tranny helps. 2020 Sport S/max tow

 

[Boogerman]

3:73 gears, one of the reasons I passed on the overland. I wish they would offer them with 4.10 gears stock.

Took mine on the first trip longer than 30 miles this weekend. About 3.5 hour one way drive to a buddies ranch. 3.73s and 35 inch tires I got good gas mileage and it felt smooth. I am really glad I went with the C load instead of E. I feel like it makes a big difference.... That being said when these tires wear out I will jump to 37's with appropriate gears.

 

[Jeeperjamie]

I was getting around 17 off the showroom floor. Put on the Banks intake; up to 18...MBRP performance exhaust/ZMAX...getting 20.5 on average (really watching my lead foot). My normal drive is on I20 @ 75 mph, cruise control on. Around town I drive my old Beetle. The 8 speed tranny helps. 2020 Sport S/max tow

What kind of setup you got,stock or are lifted with tires, just curious?

 

[ERMedic777]

Had about the same mileage before and after adding a Rugged Ridge Venator front bumper and 12k lb winch, getting around 15-16mpg. There was a small window that I was getting 17 city but that was during the first weeks of shutdown.

Went to the Outer Banks this weekend, had the best mileage I have ever seen. 18mpg! Of course, this was with the flat beach roads. Dunno where they get this 23mpg highway number from.

BTW if you are wondering where all the Gladiators are...they are all in the Outer Banks.

PS. Went to Corolla, NC to drive on the beach and see the wild Spanish horses. Of course, airing down and 4x4 is pretty much a requirement...this Lexus didn't know lol

You were in my Hometown now I am really homesick after seeing the beach lol Glad you enjoyed your trip !!!!!!!

 

[noside85]

You were in my Hometown now I am really homesick after seeing the beach lol Glad you enjoyed your trip !!!!!!!

It is an AWESOME place! I really felt like this is where Gladiators come from. I saw more than 10 there, been back in town and have seen two or three since...

 

[donaldus]

What kind of setup you got,stock or are lifted with tires, just curious?

Stock...Mine will tow small trailers, a Kubota L4701 (made outta pig-iron). Texas based so off-road is flat and muddy.

 

[dickpasman]

Man I'm feeling lucky. First 2K milage around town has been 21-22. I use cruise as much as possible. It really raises your mpg.

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