Is my Truck Defective??

[Kboeh34]

I have a 2021 1500 with a 3.0 Duramax and my mpg’s seem lower than most. I’ve always averaged 17 miles per gallon from daily commutes. My daily commutes are usually 7 miles from point A to point B. I live in Colorado, so I’m thinking that the higher altitude might be a reason for the low mpg’s. The highest mpg I’ve gotten is 22 mpg and that’s from when I make a trip from Colorado Springs to Denver. I use Hot Shot fuel additives on Every fill up and my tires are Toyo Open Country 305/55R20.

My “performance” mods are a Stillen air scoop, drop in K&N air filter, modified stock air box, 3 in air intake tube, and turbo resonator delete.

My thoughts are that the tire size and high altitude could be the cause of my less than average mpg’s. What are you’ll thoughts?

I live in Parker, but have a 2023 with the LZ0. With that short of a commute you're killing your fuel economy. Your wheels and tires are hurting it a bit too.
Driving from Denver to the springs, I will get high 20s, but I also drive like a grandpa and go 75 on cruise control. I haven't gotten 30+mpg on the highway like I used to when I was living in TX, but definitely higher than 22mpg on the highway. The altitude has an effect but the truck will compensate and adjust for the altitude.

Your speed, wheels and tires, and short commutes are causing it to be low.

 

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[Hatche90]

I live in Parker, but have a 2023 with the LZ0. With that short of a commute you're killing your fuel economy. Your wheels and tires are hurting it a bit too.
Driving from Denver to the springs, I will get high 20s, but I also drive like a grandpa and go 75 on cruise control. I haven't gotten 30+mpg on the highway like I used to when I was living in TX, but definitely higher than 22mpg on the highway. The altitude has an effect but the truck will compensate and adjust for the altitude.

Your speed, wheels and tires, and short commutes are causing it to be low.

Thank you for this info.

 

[Hatche90]

I live in Parker, but have a 2023 with the LZ0. With that short of a commute you're killing your fuel economy. Your wheels and tires are hurting it a bit too.
Driving from Denver to the springs, I will get high 20s, but I also drive like a grandpa and go 75 on cruise control. I haven't gotten 30+mpg on the highway like I used to when I was living in TX, but definitely higher than 22mpg on the highway. The altitude has an effect but the truck will compensate and adjust for the altitude.

Your speed, wheels and tires, and short commutes are causing it to be low.

I wonder if LZ0’s get better fuel mileage than LM2’s from factory. If they do then I wonder if there’s a way to get that tune uploaded to a lm2 ecm/ecu.

 

[Kboeh34]

I wonder if LZ0’s get better fuel mileage than LM2’s from factory. If they do then I wonder if there’s a way to get that tune uploaded to a lm2 ecm/ecu.

Turbo is different as well as the emissions stuff. Probably not much difference between the two in way of fuel economy. If anything the LZ0 will be worse since it makes almost 40ftlbs more torque

 

[Colorado Kid]

I am getting 20+ MPG in the city and 35 miles MPG on the HWY, I live in Northern Colorado north of Denver, but i also only have 11,000 miles on my 2024 AT4

 

[COSAT4]

Same truck on 275/65r20s and I got 33mpg from COS to central Denver last week. I typically get 38+ to DIA.

 

[Kboeh34]

Same truck on 275/65r20s and I got 33mpg from COS to central Denver last week. I typically get 38+ to DIA.

What are yall driving 55mph lol

 

[COSAT4]

No seriously - and I was slightly splintering the limit most of the way. The mpg dropped on the way home from the hockey game because we got after it. I’m really happy with the mpg I’ve been getting!

 

[Hatche90]

I am getting 20+ MPG in the city and 35 miles MPG on the HWY, I live in Northern Colorado north of Denver, but i also only have 11,000 miles on my 2024 AT4

How many miles do you drive everyday from home to work?

 

[Hatche90]

What are yall driving 55mph lol

Now you see why I’m asking if my truck is defective or if the LZ0’s have a different factory tune because I can only dream of getting 25-30+ mpg’s.

 

[Hatche90]

Same truck on 275/65r20s and I got 33mpg from COS to central Denver last week. I typically get 38+ to DIA.

This it’s crazy and I’d love to figure out how I can get that type of mpg’s out of my truck.

 

[Hatche90]

Wait, are you’ll reading your mpg’s based off of the 25 mile range, 50 mile range, or 400 mile range? My mpg’s are based off of the 400 miles range. If I switch my settings to the 25 or 50 miles range then I’m seeing mpg’s in the 20’s and 30’s.

 

[Colorado Kid]

How many miles do you drive everyday from home to work?

Retired but still drive quite a bit, but with spring & summer coming will be on my Honda GoldWing Trike which gets 40+ mpg

 

[Kboeh34]

No seriously - and I was slightly splintering the limit most of the way. The mpg dropped on the way home from the hockey game because we got after it. I’m really happy with the mpg I’ve been getting!

Ok.. So I changed my air filter last weekend, gauge only said 50%, but had one and I'm moving so just swapped it anyway to not need to move it. Since then, my mpg has been mid to high 20s... This CO air is so dusty that filter was filthy, maybe try to swap it and see if mpgs go up.

 

[Kboeh34]

Wait, are you’ll reading your mpg’s based off of the 25 mile range, 50 mile range, or 400 mile range? My mpg’s are based off of the 400 miles range. If I switch my settings to the 25 or 50 miles range then I’m seeing mpg’s in the 20’s and 30’s.

Gotta be 25 mile if he is getting 38+. I have only ever seen that high coming down hills in the mountains, I keep mine on 50 mile normally, but my 400 mile is usually mid 20s. 50 mile for me is mid 20s to low 30s depending on how and where I am driving too.