GMC Sierra 1500?

[MaverickPro201]

Looking at possible going back to a Gas burner. Looking at used 2017 up. What should I know about these GMC Sierra's 1500's?
What kind of MPG do you get with one.?
I have not owned a Gas Burner since 1989. Always a Dodge Cummins, 1990, 1994, 1998, 2003, and now 2012 1/2. Just do not tow heavy like I use too.
All help appreciated
Thanks.

[Aggie]

Bad transmissions is the biggest problems my friends have had.

[AirForceAngler]

I have a 2021 Silverado with the 6.2 and 10 speed. Loving it so far! Great power and I'll generally get over 20 MPG running empty. 15 or so pulling my little Lund at 75 MPH. Some of these did have problems with the lifters needing replaced, knock on wood, I haven't had an issue yet.

[Rangerdeepv]

Just traded my '17 Sierra 1500 double cab on the '21 Yukon. My biggest gripe was the transmission seemed 'tired'. The quality and reliability of the truck are great. The 5.3 pulled my 4k+ lb bass boat just fine. Best on the highway was 22 mpg and best in town............well 14-15. One PVC valve was the only issue over 5 years and 75k miles. If it were a crew cab it would probably still be in the driveway. The Yukon has the baby Dmax in it with the 10 speed tranny and so far it is sweet.

[shapfromla]

I own a 2018 GMC Sierra with the 6.2 liter and 8 speed transmission. Beware the 8 speeds. I had transmission issues at 20,000 miles and the transmission had to be replaced at 45000. I have owned GMC's all of my adult life with flawless reliability until this one. My confidence is very low in the new 8 speed that was installed. I love the 6.2 liter and the truck is very comfortable, quiet and rides great. Pulls my Basscat Eyra effortlessly. Just be aware of the 8 speed transmission issues.

[jbh3]

Adding a Range module to disable the fuel management cylinder deactivation improved the drive-ability of my 2018 5.3/6 speed a LOT.

[Dagwood_55]

Wait a couple of months for the ZR2 Silverado... Baddddd

[n2ratfishin]

http://www.bbcboards.net/showthread.php?t=1163950

[berudd]

I have a 2018 with the 5.3L and the 8-speed. The transmission has some issues. It will jerk and studder at low speeds when first starting up. Seems worse in the summer on cold starts. Once up to operating temps there are no issues. The dealership did but a different kind of fluid in it and that made it better but it is still there. This has been the case with the 8-speed in all vehicles but I have not heard any issues with a 6 or 10 speeds.


Cruising at legal speeds without a load I get around 22-23 mpg. Towing my 20TRX its about 12 I think. The truck pulls my boat with ease. Yes, the 6.2L has more power and will pull it away from a stop light faster but I haver never felt the need for more power. I am not sure if it is still the case, but if you want to realize the full performance of the 6.2L, you have to run premium gas. This used to be stated in the owner's manual. Without it, the engine will start to knock and the engine management system will de-tune it to correct for that.

In addition to the power, the chassis\suspension is great for towing and hauling as well. No its not an "I don't even know its back there" thing because I actually pay attention to what is going on and I am not prone to hyperbole. But, it is very stable with the boat. I filled it up with mulch, 2 yards, a few weeks ago and about all I noticed was it rode a little smoother.

I do find all the little notifications I get from time to time on the infotainment system to be annoying but I don't think you can buy a modern truck that doesn't have some of that stuff.

[dickenscpa]

I have a 2013 Avalanche, this is my 4th one and I love these things. Gotta take care of this one because they don't make them anymore. I have the 6.0 with a 6 spd and the first thing I did was eliminate the active fuel management thing. I had an 02, 04 and an 06 Avalanche without AFM and put 210k, 197k and 278k on them with no problem. Didn't want an Avy without cladding which was unavailable 07-13 so I bought a Dodge Ram to bridge the gap until I folded and bought an uncladded Avy. I have almost 150k trouble free miles on this 13.

That MDS (same as AFM on GM) was the death of my Hemi. On the Ram the trans went out at 88,627 miles. That trans went out at 135,435 mi and the engine dropped a valve at 140,901. I had a new engine put in and trans #3 and the rear diff grenaded at 194k.

I just drove from TN to AZ and back (5260 mi round trip) and with four people and a LOT of luggage in the back I got 19.5 mpg from my driveway back to my driveway. We stayed a bit in TX, NM and AZ seeing different sites and getting stuck in bad traffic. If it weren't for that pure hwy mileage was over 20 mpg. Now my Avalanche is heavy and built off a Suburban and not a Silverado/Sierra.

[dcmclassic]

I have an 18 1500 2wd with 5.3 and 8spd. 45k and been a great truck so far. Before this one I hadn't had a GM since 2011, bought this one with about 15k on it. Gets a combined 22mpg for my daily commute which is about 50/50 heavy stop n go and highway. On long highway trips we regularly see 24-26mpg(at legal speeds). I'm currently boatless but before I sold my boat it towed great, about 12-14mpg towing which I think is pretty average for towing with1/2 ton gassers.

[jc1992]

Alright I got a question for everyone that are actually getting good gas mileage, what are y’all doing to achieve that? I got a 19 RST 4X4 with the 5.3 8 speed and it gets 17 on the highway and 11 in town. Show 13 on average and that’s empty. Put the boat or tractor behind it and of course it’s about 8-11 miles per gallon. I’ve had mine since august 2019 bought new and now has almost 50k. Other than the early software bug issues that was resolved, we haven’t had any issues with ours except now we have lost the AM/FM on the radio. Says tuner is unavailable. Taking it in and seeing what that is about. Luckily got that extended 100k number to number warranty. My dad bought a 2020 Silverado custom with the 6 cylinder 6speed and has had zero issue 4X4. Pulls our compact tractor and boats great. Also gets 22 on the highway and 17 in the city. Currently has 14k miles

[Ranger391v]

jc' ................ not to be a smart azz, but I honestly don't know ....... I just drive it. I will say though, I don't drive near as fast as a lot of people seem to. It seems that everybody thinks '10-over' is the norm. .............. and 'east Texas' is a lot like SC as far as hills, etc.

My '19, 1500, Crew Cab, LT, 4x4, 5.3L, 8spd, 3.42, Max Trailering ........ that I currently have +21,000miles on it ...... bought it Sept' 2019 (a month behind you).
1. The "Life Average" (all miles on the truck, counter never reset) is sitting on 19.something MPG right now.
2. I've not reset the second counter for +6,000 miles now and it's sitting on 20.9MPG. ........ during that time I've only towed the utility trailer w/SxS a few times.

Typically it easily gets 20-21 MPG for the life of the tank of fuel. That's mostly 2-lane highway driving, going to town for weekly shopping. I've seen 50mile averages @60mph of 27MPG before while traveling long uninterrupted stretches of highway. Usually, it's 14.1-14.5MPG towing my Z520 or my 12' utility trailer with Polaris Ranger 1000 loaded on it. Dang trailer gate is like a parachute. But I'd say my numbers are more in line with your dad's truck of 22 Hwy and 17 City. The Highway number isn't hard to get and is typically exceeded if 55-60mph and not stopping-starting or passing people ....... or following that person that can't go down the road at a consistent speed.

With that said, my "Life Average" is pretty high because I seldom tow with that truck ............. I got a '16 2500HD for that.................. bass boat, duck boat, SxS, tractors, and all other messes I get roped into and it's the 2500HD's duty. My '19 is really more of a 'travel', 'Sunday', 'family' vehicle.

Getting back to the 2019 truck .......... I have noticed that the averages seem to range more and not near as 'consistent within a tenth of a MPG' like most trucks I've had in the past. Driving style and speed seem to impact it more.

Good Luck!!!

PS: My dad bought a 2021 like mine, but a Z71 and LTZ. Basically, he wanted a Max Tow identical to mine but couldn't find it. So he has the 5.3L, 8spd, but the 3.23 gears ......... and his fuel mileage is practically identical to mine. He's only got a few thousand miles on his so not a lot of data.

[Tuck935]

Just a heads up that there is a 2.7L turbo out there. I was not aware when I bought my '19 demo model. I only knew of the V6 & V8 options. I was furious at myself for not knowing better. That being said, my best highway mpg is 33.9, and I average 23-25. I have towed my 19' Triton to Florida from Indiana 3 times now and it has had no problems with power, getting up to speed or going through the mountains. I average 13.5mpg going south and 12.5mpg coming north, (elevation differences and probably a heavier foot coming home). I had to replace something related to fuel evaporation reclaimer, was told it was due to trying to put too much fuel in the tank. The truck has honestly surprised me. Just over 55,000 miles now so time will tell.

[turboss08]

I just went from a 2020 Sierra 5.3 to 22' AT4 with 6.2 and ironically, the 5.3 averaged about 12.5-13 with the boat behind her and the 6.2 averages about 13.5-14. Not great compared to a diesel but much more powerful and fun to drive than the 5.3. A friend has a new Sierra with the 3.0 Duramax and averages about 17-19 mpg while towing his boat.

The biggest key is to just drive a little slower. my numbers are at 73-75 mph. if I creep up to 80-ish, i'm down to 10-11 mpg. Never really cared before but now on long trips with gas at $4.25+, 2-3 mpg makes a pretty good difference in the wallet.

[Rangerman522]

I’ve got a 2018 GMC Sierra Denali that I bought new with the 6.2 and 8 speed transmission. Had zero issues with it and it pulls my heavy Ranger Z522 with ease up and down hills. Absolutely the best gasser I’ve ever driven. Also, my bad back loves the magnetic ride control. I also heard that the new transmission fluid that they begun putting in the later year models has made a big difference in the transmission “shuddering” that had been occurring.

[DaveBrabec]

Never had a transmission issue with a GM truck.I will say a 1500 with a 5.3 is plenty for a boat.Had a 2014 .My 2018 6.6 diesel gets better mpg towing or empty than the 5.3 did

[berudd]

I’ve got a 2018 GMC Sierra Denali that I bought new with the 6.2 and 8 speed transmission. Had zero issues with it and it pulls my heavy Ranger Z522 with ease up and down hills. Absolutely the best gasser I’ve ever driven. Also, my bad back loves the magnetic ride control. I also heard that the new transmission fluid that they begun putting in the later year models has made a big difference in the transmission “shuddering” that had been occurring.

I think that is what the replaced mine with in my 2018. It is better but not fixed.

As to getting 20+ mpg, I do it by setting the cruise on 75 and not driving like I’m in a race. I don’t baby it I just don’t hammer it. If you have an AT4 you maybe have bigger tires and/or lower gears which will affect mileage. And your right foot will as well. But towing, mileage does drop to the mid to low teens.