Real World Fuel Economy - 6.0/6spd My Reality - How's your 6.6 stack up across it's life?

Leonardo Willi · March 25, 2023

This is over the life I've owned this 2016 Silverado HD since new. Everything from towing 10,000lbs, carrying 2700lbs, or pulling my 17' Bass Tracker (truck doesn't even know it's back there). 70% of the miles empty running interstates and toll roads and short runs to town on basically flat roads up here in NW Ohio. Instead of hills like down south or over east, we have wind to deal with which sometimes almost as bad as hills. On the interstate, sure, I can ave 22-23mpg if I set the cruise at 55mph - but we run 70-75 on turnpike and then she's like 16 with a tailwind.

I'll be happy if the new 10spd gets me just a couple but that might be wishful thinking. Either way, we don't buy these things because of the great fuel economy, we buy them to perform when we need them and that's the price of admission. I've never had a truck I could brag about it's ability to sip and not gulp ever.

Just curious what everyone's reality is. I know pulling that 10,000lbs, it's like 7 or 8 but it takes energy to move mass.

Almost assbackwards for me to justify a truck, but living in the country, sometimes I have to haul water for the house and keep the pool full. When I need it, it's a need.

Pryme · March 25, 2023

Mines only at 4,200mi and have only towed for 400 of that. It’s at 14.6 though for the lifetime so far.

skorpyd · March 26, 2023

I was never one to constantly check mileage as it's kind of like you said, Ya don't buy these trucks for mileage. I had a 16 2500HD with the 6.0 and I didn't check a lot but I never got better than 11-12 without a load, and towing it was like 5-9.

My 2020 3500HD gasser was very surprising in that it not only had a lot more power it got significantly better mileage both towing and not. Almost 140,000 on my 2020 and can't wait to get my hands on a 24 with the Allison.

Pryme · March 27, 2023

6 hours ago, skorpyd said:

I was never one to constantly check mileage as it's kind of like you said, Ya don't buy these trucks for mileage. I had a 16 2500HD with the 6.0 and I didn't check a lot but I never got better than 11-12 without a load, and towing it was like 5-9.

My 2020 3500HD gasser was very surprising in that it not only had a lot more power it got significantly better mileage both towing and not. Almost 140,000 on my 2020 and can't wait to get my hands on a 24 with the Allison.

Man you drive a ton!!! What do you do to rack up those miles?

Randal Scott · March 27, 2023

My 2003 2500hd with the 6.0 and the 4 speed transmission got between 10 - 12.5 mpg daily driving. I have gotten 15 mpg on the highway at 70 mph. 8.5 mpg pulling the 34 foot fifth wheel camper.

My 2020 2500hd 6.6L gasser gets 13 mpg around town. And when I was working, it got 15.9 mpg back and forth to work. Empty on the highway, it is 15-17 mpg. Long run 19.3 mpg. Pulling the fifth wheel it's 9-10 mpg locked in 5th gear going 70 mph.

Leonardo Willi · March 27, 2023

5 hours ago, Pryme said:

Man you drive a ton!!! What do you do to rack up those miles?

I'm an extreme exception and I know that. A new C8 is next and will collect even more dust, but that's life in my world. All pays the same.

I really didn't think the mileage would be that bad, but that's what's real for me with no bullsht ~

64BAwagon · March 27, 2023

My 2021 Crew cab 3500HD got almost the same towing mileage with a 12k fifth wheel as my 2018 double cab 1500 5.3 got pulling our 6500# travel trailer. The 3500 with the 6.6 seemed a little more evenly matched to the task than the 5.3

I always say that there a two things that guys will lie about measuring...... One of them is mileage.

nards444 · March 27, 2023

about 12mpg on the 6.6

Flatus · March 27, 2023

I check my mileage on almost every fill up. I actually filled up today and hand calculated 12.59 mpg. My lie-o meter read 13.4 at fill up today. It is always .8-1.3 mpg's optimistic. I pretty much always get 12.5-12.9 on my normal daily driving without ant towing involved. I do a lot of stop and go daily though. The best I have seen on a unloaded highway trip was 15.9 hand calculated. I tow a small Microlite camper which only weighs about 5100-5200 lbs loaded and I get anywhere from 8-9 mpg's while pulling.

skorpyd · March 28, 2023

On 3/26/2023 at 8:31 PM, Pryme said:

Man you drive a ton!!! What do you do to rack up those miles?

I manage a few properties and one is in North Dakota, the rest are in several locations in Michigan

Stand By · May 27, 2023

I can manage 16-17 at 80 with cruise on if the grades and traffic aren't bad. What's nice though is when you have to get on it to get by somebody at freeway speeds, you have a lot available. 2 lanes, when able to manage a constant speed around 60, it'll see 18. Just 12 around town. The mileage was a little worse before it was broke in. I was worried taking it up to Michigan's Upper Peninsula much, would eat at the wallet. Fortunately, without much freeway use up there, it did pretty good. Not towing of course, but more of that coming soon hopefully.

Dunn · May 27, 2023

On 3/27/2023 at 12:25 PM, nards444 said:

about 12mpg on the 6.6

Yep, that's mine too

My 22 1500 RST wasn't much better tbh...like 13.6

sabre364 · May 27, 2023

On 3/28/2023 at 8:12 AM, skorpyd said:

I manage a few properties and one is in North Dakota, the rest are in several locations in Michigan

What, if any maintenance, have you done to your 2020 with all those miles? Any major issues?

Leonardo Willi · May 27, 2023

On second tank, 600 miles down, got some interstate time yesterday - the Lie-O-Meter I hope is lying in the wrong direction. 6.0 I have to say impressed me on highway. 6.6 saw promising moments, but so much more frontal pushing air.

HP4 · June 3, 2023

When I drive around town I try and keep my shifts at 2100 or below. It's not hard to do most of the time. Did some running around tonight and only had to get on the gas hard a few times. Drove on the interstate for about three miles, 12 miles or so on 50-55mph roads and the rest was in small towns and back roads getting to/from my house (20-30 mph zones). AC was on the whole time and I drove over the speed limit most of the time. Took very little effort to drive easy and get 16.8 mpg. I've had the truck since new and it doesn't burn a drop of oil. Spends about 60% of its life pulling a 5000 pd. trailer.

When I got in the truck tonight my son had been driving it and the MPG was at 10. Teenagers.... LOL