2020 Duramax fuel mileage

[mowingman]

Does anyone have any real life fuel mileage numbers yet for the Duramax engine with the new 10spd transmission. I am looking at a new 2500 or F250. Thinking the 2500 would get better mileage with the 10 spd trans. Can not find any MPG numbers for the new Chevys/GMCs.
Thanks.

[BandJCarm]

I may be wrong, but I don't believe HD trucks publish mileage specs. Why? Cause the Feds don't make them. AND, including HD truck mileage would skew the CAFE mpg standards down, so they don't want to.

[NMWildcat]

I don't think the mpg has noticably changed in the last 10 years for HD diesel trucks, regardless of manufacturer. If the brand new ones are any better, it isn't by much
Funny thing is, my 2007 Duramax gets the same or better than much newer trucks. Go figure.

[mzbrandi]

I made a trip from Wickenburg, AZ to Carson City, NV with an average MPG 18 to 20 depending on how level the road was at about 73 mph. Coming back with my rPod was about 10 to 12 mpg at about 65 mph.

Brandi

[joelabq]

Just bought a 2020 Silverado, had an 07 classic. Mileage is about the same, but there power and smoothness of the ride is amazing. I loved my LBZ, but I didn't care to daily drive it. This truck I do and I want to.

I'm getting about 17 mpg hand calculated, with just under 2k miles on it. Currently having to sit in a lot of traffic due to nasty construction in my hometown. That's also with colder weather remote starts, etc.

This is also my first short bed truck, but with the extra length of this 6'10" bed, I bought a standard hitch and hooked up my camper and it's worked out great. Good clearance on my fifth wheel.

Happy to answer questions if you have any.

Joel

[Teetime]

I have a 2018 GMC 2500 with the 6.6L, Allison transmission and 3.73 rear axle. On my recent trip, 2158 miles, avg fuel economy 12.1 mpg.

This was towing combined gross weight (CAT Scale) of 16,400 lbs truck and camper (6800). We were also fighting winds most of the way accross NM, AZ, and CA.

On the return trip, after leaving our camper in storage, the average was 20.8 MPG, not towing.

I would imagine the 2020 would be near those numbers.

[mowingman]

Thanks for the replies. Sounds like the mileage is still about the same, maybe just a little better with the new 10 spd. But, it is very interesting to hear that the slightly longer, (short), bed works well with a 5th wheel hooked on. I have not owned a GM pickup for many years, but I do like the towing features on the new HD trucks, and am still intrigued by the 10 speed trans. Going to have to do some thinking on this one.

[joelabq]

Originally Posted by mowingman

Thanks for the replies. Sounds like the mileage is still about the same, maybe just a little better with the new 10 spd. But, it is very interesting to hear that the slightly longer, (short), bed works well with a 5th wheel hooked on. I have not owned a GM pickup for many years, but I do like the towing features on the new HD trucks, and am still intrigued by the 10 speed trans. Going to have to do some thinking on this one.

Here's a near 90 degree on unlevel ground. The trailer was on my driveway incline which is about 2 feet higher then the truck trying to simulate a worse case scenario.

B&w hitch set straight up, could set it two inches back but didn't want to.

[mowingman]

Thanks for the photo. Yes, I have a B&W hitch also. It is the Companion hitch, so I will have a B&W installed in the truck so I can continue to use my hitch base.
Jeff

Originally Posted by joelabq

Here's a near 90 degree on unlevel ground. The trailer was on my driveway incline which is about 2 feet higher then the truck trying to simulate a worse case scenario.

B&w hitch set straight up, could set it two inches back but didn't want to. Attachment 219732

[thompsonbb]

Hello, 2019 Chevy 3500 6.6, 5th wheel weight 16,400. Pulled 21000 miles this year. Average 11.5 loaded, 17mpg hiway empty, about 15 mpg city empty. Love love this truck. 60 years old owned 2 ford diesels, 1 dodge diesel, 3 Chevys, best truck ever! The ride is great.

[OldSoldier]

Originally Posted by mowingman

Does anyone have any real life fuel mileage numbers yet for the Duramax engine with the new 10spd transmission. I am looking at a new 2500 or F250. Thinking the 2500 would get better mileage with the 10 spd trans. Can not find any MPG numbers for the new Chevys/GMCs.
Thanks.

Doubt that we will get any SIGNIFICANTLY better mileage from the new 2020. Maybe a little. HOWEVER, with the new 10 speed transmission, I expect we will get a significant improvement in the engine's PERFORMANCE as the engine will spend a lot more time in the peak portion of the TORQUE curve, therefore better pulling performance.

[Nala47]

Originally Posted by thompsonbb

Hello, 2019 Chevy 3500 6.6, 5th wheel weight 16,400. Pulled 21000 miles this year. Average 11.5 loaded, 17mpg hiway empty, about 15 mpg city empty. Love love this truck. 60 years old owned 2 ford diesels, 1 dodge diesel, 3 Chevys, best truck ever! The ride is great.

09 2500, 6.6 with 6 speed Alison, total weight 18,500. Just pulled 7,000 miles and got ll.5 pulling and get about the same when solo.

[BandJCarm]

The question was about the 2020 model Duramax.


I doubt the mileage is changed appreciably either way.


As for the GMC Duramax, I will always own GMC products until they stop making a tool to do the job I need. If I can't find a GMC product to do what I need to do, I'll gladly shop elsewhere.

[GWJohnson]

We have a 2020 GMC 3500HD Denali 4WD (SWR) pulling a 2020 42 ft FR Riverstone tipping the scales at about 18,000 lbs loaded weight. We have 5,500 miles on the truck and have pulled the 5th wheel about 2,500 of that, both in the midwest and from Colorado to Phoenix through mountains. The reason I waited for the 2020 GMC was because of the 10 speed Allison tranny. The top 3 gears are overdrive and the exhaust brake works extremely well. I have a 3.42 rear axle ratio. I had an Allison tranny in our 41 foot diesel pusher motorhome for 10 years & 65k+ miles and it performed flawlessly. On interstate at 75+ mph (w/o towing), we averaged 22 mpg today from Fort Collins, CO, to Albuquerque. Pulling the rig, we average between 9.5 & 11 mpg, depending on terrain. Hope this helps.

[jrk341]

2020 ford f250/350 have a 10 sp tranny with the diesel and new 7.3 liter gas engine.

[Daycruiser]

Originally Posted by mowingman

Thanks for the replies. Sounds like the mileage is still about the same, maybe just a little better with the new 10 spd. But, it is very interesting to hear that the slightly longer, (short), bed works well with a 5th wheel hooked on. I have not owned a GM pickup for many years, but I do like the towing features on the new HD trucks, and am still intrigued by the 10 speed trans. Going to have to do some thinking on this one.

As long as you know that the new 10spd is not a real Allison Transmission. Its an Allison branded transmission built by GM, not Allison.

[Springerdad]

And, if my memory serves me right, that 10 speed tranny was co-ventured by Ford and GM. Ford was going to use it in their trucks, and the GM in their performance cars. Ford delayed the release of their trucks until they got the programming right. Looks like GM got the hint and is using it in their trucks too. Someone correct me if I'm wrong.

[NMWildcat]

Nope, you are correct. https://www.autoinfluence.com/11-thi...-transmission/

I have been driving my Dad's 2019 F150 with the 10 speed for a few weeks now. It shifts very smoothly on the highway. In town, not so much, especially at take off.
I'm always very glad to get back into my 2007 2500 Duramax

Originally Posted by Springerdad

And, if my memory serves me right, that 10 speed tranny was co-ventured by Ford and GM. Ford was going to use it in their trucks, and the GM in their performance cars. Ford delayed the release of their trucks until they got the programming right. Looks like GM got the hint and is using it in their trucks too. Someone correct me if I'm wrong.

[Springerdad]

Originally Posted by NMWildcat

Nope, you are correct. https://www.autoinfluence.com/11-thi...-transmission/

Blind squirrel moment.

[joelabq]

Originally Posted by NMWildcat

Nope, you are correct. https://www.autoinfluence.com/11-thi...-transmission/

I have been driving my Dad's 2019 F150 with the 10 speed for a few weeks now. It shifts very smoothly on the highway. In town, not so much, especially at take off.
I'm always very glad to get back into my 2007 2500 Duramax

The 10 speed in my truck is smooth 100% of the time. I loved my LBZ, but I'm really liking this 10 speed. There is a gear for everything. There is no skipping of gears except first if your not in your haul. The only part I don't like is there is a lag at 5 to 10mph because of the second gear starts and the programming to avoid soot for the dpf.

Throw it in tow haul And hook up a trailer and it's a night and day difference.

My LBZ was chipped with Idaho Rob from ATP trucks. I don't miss the truck as much as I thought I would. Except for the payments. The LBZ was paid for...