Hey fellas. I have a 2022 at4 6.2l coming from a 2015 ram 1500 5.7l . As I do with all my trucks I put 305/55-20 on them . I’m running nitto420 and love the look and the ride. I live in upstate ny, and with the mountainous terrain , even highway is shitty with about 15mpg avg. but I took this truck to NC 900mi away for my first trip and got avg 21 mpg ! I was impressed and maintained 20mpg for the ride home. Recently I just went to Boston mass, (all highway) and got 20mpg again. Driving habits are huge and I love to hear my exhaust but my wallet deters me. Lol. These trucks do great mpg on highway and flat land , once u hit the mountains or pull expect the expected .
On hwy or interstate speeds, if on flat land with no headwind, 15 to 16 mpg is possible. Interstate at 80 to 83 mph will take a bump. 65 to 70 on non-interstate, flat roads, no headwind i can get 17.
Last friday I drove 990 miles from Nebraska to Montana (where I live). It was an incredibly windy day, I was heading west into a very strong WNW wind. 25 MPH+ constant wind, gusting had to be double that often. Talk about killing fuel mileage. I maybe got 10 MPG the first 400 miles of the trip going from northeast Nebraska, up in to South Dakota to I90, then into Wyoming and finally to MT - all on I90 once I got to the insterstate in SD. Since I am running 34" tires, I used a very accurate GPS app with a detailed stats screen to get my actual miles driven since the larger tires effect what the DIC shows for miles travelled and figuring the MPG on the DIC screen. It was brutal driving conditions.
If anyone has driven in Nebraska, I90 in South Dakota and Wyoming, you know how bad the winds are in these states/areas. Since my path is West and some north going from northeast Nebraska to the mountains of Montana, there is pretty much always a head wind. Winds obviously general flow west to east, so fuel mileage heading back to Montana (travelling west) is always worse than travelling from Montana to Nebraska (where I grew up) travelling east. Also, there is obviously more consistent uphill driving heading west. Nebraska's elevation is about 1000 feet, where I live in MT my house sits at 6100 feet. So going uphill more hurts MPG also.
Once I got into the mountainous portion of MT, I also hit some heavier snow. It was snowing and the roads weren't good at all, especially in the passes. Conditions travelling in snow/winter weather will obviously effect MPG negatively.
I got a lot better mileage on the last 3rd of the trip, despite the snow and driving in mountainous terrain, mostly because the winds weren't nearly as bad as they were the first 400 to 500 miles of the trip. Overall, I averaged just under 13 MPG for the trip, which given the first 400 miles I averaged about 10 MPG, wasn't all that bad for the trip avg. I did have to drive slower in the snow conditions once in the mountainous areas of MT, so that did help my MPG.
I just wish this truck had a 30+ gallon tank. 24 gallons is just way too small. I left Nebraska with a full tank, filled up in Murdo SD, then Moorcroft WY, then finally Columbus MT. Once I got to my destination, I filled up again to get an accurate reading. I used around 75 gallons of fuel (would have to look at my notes for the exact amount). It cost me $264 in fuel for the 990 mile trip. Would be nice to have a bigger tank so that one could get more range. My 2020 AT4 3.0 diesel usually averaged about 5 to 6 MPG better than the 23 AT4X 6.2. Both trucks larger tires, levelled front. AT4X I do have a bed cover, which is supposed to help a bit with MPG and less wind resistance. Not sure if it really does, though.
Anyway, that is what I got on that particular trip. I don't see any way to get much better mileage with the 6.2. I try not to hammer it, which it is fun to step into the pedal on the 6.2, but that will severely decrease MPG. So driving normally 2 or so over the speed limit (pretty normal for most drivers on these roads), not stepping into it, using cruise most of the time (where possible). I don't think there is any way to increase fuel mileage much realistically. Maybe a cat-back system and a larger more open flow air filter system would help a little. But likely not a lot. Since there are no tuners for the 23 refreshed trucks, no way to tune it. Not sure a tune would help much on the 6.2, but it is possible.
