Never get what you looking for around town. After it brakes in some you may get better on the highway. Keep it about 55 for best mileage.

 

Not that bad mileage. Definitely not going to get 16-17 around town.

 

I‘m more than happy with my 2023, 2500HD, Duramax averaging 15-16 mpg local and I’ve seen as high as 22-24mpg on the highway with Cruise. My previous ride a Gas F250, got 12 mpg if I were lucky. Sadly, with todays diesel prices, I figure I’m breaking even, although getting better performance with the Duramax. Hopefully diesel will keep dropping.

 

Once broken in, you can expect low teens in town and mid to upper teens on the highway. Sometimes you may see 20 or so while riding, but not over a tankful. Unless you're steady and constant speed through an entire tank, that is.

 

Sounds like you are getting great mileage. You really can’t say “expecting to get”, these trucks are not rated by the epa, and they can vary. But what does it really matter what you get empty, these trucks are made for towing and hauling, what kind of mileage are you getting when towing heavy? The reason for that kind of mileage is that you are trying to move an 8,000+ pound brick that is making 445 HP and 910 torques.

 

Towing can vary for sure, as you said. I have seen my towing MPG steadily increase as the powertrain breaks-in. While towing my 42', 15k lb fifth wheel, it's up to 9.0 mpg according to the towing app in the infotainment. Of my almost 17k miles on the truck, nearly half of those are from camping trips. So far, it's overall is about 2 mpg better than the 6.6 gas I had before it. Very pleased with both powertrains, honestly.

 

Our 2021 Chevy 2500 crew cab Duramax gets about 12-14 around town. When rolling empty on the highway I have gotten 25-30!! Mind you that is running 65 mph or so and just being gentle on the right foot. When the 32' fifth wheel is connected the best I get is 10 mpg. That is the best and it is a rare outcome. Typically I get under 10 mpg when towing.
What I know about the emissions system on this truck is that city driving is not healthy for the diesel particulate filter. The truck needs 20+ consistent highway miles every week to keep the DPF clean. If there is a lot of start / stop city driving the truck may generate codes that refer to servicing the DPF.
That's a nice truck you have!!

 

2022 3500 AT4 L5P, getting 15MPG highway cruising empty, 9-10mpg hauling my 10k 5th wheel, and around 10mpg city driving empty. If I need to drive in the city I use my wife's compact SUV.

 

This is my first post, not sure if I'm in the right place.
I got my new 2022 gmc sierra 2500 at4 l5p back in October. I have not been getting very good fuel mileage, around 9-11mpg, around town and 15-16mpg on the highway. I was looking around and was expecting to be getting about 16-17 around town. Any ideas what could be causing such low mpgs?

Sounds about normal for a new truck. If you don't have 20-30,000 miles on it yet, report back when you do.

 

Not to mention, since you go off-reading and need to climb over trees and through ruts you got the AT4 off-road Package which has bigger off-road tires that are going to negatively affect your mileage. I would imagine you bought a big heavy diesel truck to tow heavy and the AT4 package to go off roading, as long as it is doing those things that you bought it for I would say your mileage is pretty decent.

 

I recently got a 2022 lp5 2500 and I’m very happy with the fuel economy compared to my LML. My LML was a dually so I know the added rolling resistance hurts, but my 2022 LP5 is getting around 12.5 mpg ( hand calculated) hauling a 35 foot 2 car flat trailer loaded with 2 mid size cars. I love the 10 speed as well because I never find myself stuck in between gears of where the motor wants to run rpm wise.

 

My LML has a lifetime average of 14.7 with 125K on it. It’s bone stock andI live in a rural area that is pancake flat with no city driving. What kills me is the slow driving around the farm and idling. That really pulls the mileage down. My new 6.6 gas is getting about 12.7 average so with cost of fuel is actually cheaper to run the gas right now. I have a little experience with my father in laws 2020 L5P and it does do a little better on mileage than my LML but not significantly better from my experience. But the power of the l5P with the 10 speed will out pull the LML pretty easily too.

 

I’ve been pretty disappointed with the mileage of my ‘22 vs my 2019. I reference the computer readout on both so it’s apples to apples. I seem to average 12 around town on the computer. On the highway empty at 68 it’ll average 20.5 on the 25 mile setting. That’s ok. Pretty close to the old one, but in town it’s way less. This is my only complaint on the truck other than the exhaust brake, but it’s a trade off I guess. Each new year Duramax I’ve owned (16,19,22), the MPG go’s down, but the trucks also get heavier and drive better. I’m only at 2900 miles. We’ll see what happens moving forward. The 24 should get 9 mpg around town by my estimations.

 

my 2021 ltz has 42k miles I get 10-12 towing 15-17 city/stop go and on highways it's about 20-21. measured by dividing gallons into miles between fillups. I'm average 17ish for the last 42k miles.

buttttttt..... I did not buy the diesel motor for mileage. I bought it to ensure as much as possible a safe ride for the wife's horse when trailering him.