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We’re Driving The 2020 GMC Sierra 1500 Duramax – What Do You Want To Know?

We’re spending the week with the 2020 GMC Sierra 1500, the new-generation truck that’s built on the GM T1 platform. Our test pickup is equipped with the turbo-diesel 3.0L I-6 LM2 that’s part of the Duramax engine family, rated at 277 horsepower and 460 pound-feet of torque, and it’s mated to the GM 10-speed automatic transmission which transfers power through either the rear or all four wheels.

Our Sierra test unit is also a Crew Cab Elevation trim level with four-wheel drive and the short box. It’s painted in the optional Satin Steel Metallic paint and fitted with the Jet Black cloth seat trim. The Elevation edition is mostly a styling package derived from the SLE trim level, adding a monochromatic appearance with blacked-out body trim and wheels to give the vehicle a nice bold look.

Here’s a quick breakdown of what the package includes:

  • Trim-specific blacked-out 20-inch wheels
  • Distinct monochromatic door handles, bumpers and grille surround
  • Black exterior accents, including grille insert, tow hooks and side window trim

Note that our 2020 GMC Sierra 1500 isn’t equipped with the optional CarbonPro carbon fiber box or the MultiPro tailgate, since the idea behind the Elevation package is to keep the price low while still offering consumers a fair amount of standard equipment.

That said, the truck we see here does have a few options piled onto it, like the Elevation Value Package which adds a 10-way power driver seat with power lumbar, rear wheelhouse liners, dual-zone climate control, heated front seats and steering wheel, an automatic rear-locking differential and a trailering package.

There’s also the Preferred package which adds the eight-inch infotainment screen, a 120-volt power outlet, a Bose premium sound system, a power sliding rear window and the HD Rear Vision camera. Finally, our truck also has the available Driver Alert Package 1 which adds Rear Cross Traffic Alert, Front and Rear Park Assist, Lane Change Alert and Blind Zone Alert, as well as the power sunroof standalone option. The final price as it sits is $51,795.

We will have the 2020 GMC Sierra 1500 Duramax for a week where we’ll specifically be observing its real-world fuel economy to see if it’s worth opting for this diesel engine over either the two available 5.3L V8s (the 5.3L L82 V8 or the 5.3L L84 V8) or the 6.2L L87 V8. So if you would like to know more about this truck beyond the spec sheet, ask your questions in the comments section, and we’ll reply in a timely manner as part of the GM Authority interactive review.

Ready…. set… go!

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Comments

  1. I’d like to know how fast the engine warms up from cold start to maybe 120F or whenever the coolant guage moves off low since it has that different cooling system design.

    Reply
    1. Going from a 35F cold start is easy. 0F is going to take a lot longer per degree increase. Will be hard for them to show a proper cold start this time of year.

      Reply
      1. Cold starts for today’s Duramax diesels are no problem even down to 0 degree F.

        Reply
        1. It’s not that it’s a problem, he was wondering how fast warm up takes

          Reply
    2. When will this engine be available for sale at the dealerships?

      Reply
      1. I test drove one in early March. Loaded AT4. Loved the powertrain in it. Rode incredible.

        Don’t think you’ll be disappointed.

        Reply
  2. Let’s a see a V-box 0-60 run as follows:
    4Auto
    Brake-torqued
    Sport or Tow mode depending how it’s equipped

    What is observed high way mpg cruising at 65mph for a short loop, like 25 miles of casual highway

    And if you have the mini Duramax you have to see how it trailers. Let’s see how it handles 3500lbs and two adults on board. That covers an averaged sized fiberglass boat, enclosed toy hauler, etc. As a sub-test, see what the highway MPG is towing on that same 25 mile stretch at same 65mph as above. Good comparison of empty vs trailering.

    Reply
    1. Can answer some real life towing. I have the 2020 gmc slt 4wd, 3.0 duramax, short bed with the x31 package. I pulled a 4900 lb jayco travel trailer, 2 adults and the requisite camping gear, (cooler, grill, chairs, truck bed full of other stuff, mostly lightweight), camper loaded with bedding and clothes, fridge with food, pantry stocked. I towed from Greensboro NC to Seiverville TN which is about 265 miles including through the mountains. I got 13.6 mpg uphill and 14.4 mpg coming home. Friends, that is fabulous fuel economy for trailer towing especially with some dynamic road conditions and mountains. And it towed like butter, easy to forget the camper was even back there. My wife and I took a trip to the coast, abut 240 miles level interstate driving and I got 26.5 mpg doing the speed limit, which means I was trying to see how efficient I could be . Normal driving around town and going to work I’m getting about 22.5 mpg.

      Reply
  3. That’s a pretty nice looking truck. how are the panel gaps, do they fit well? Honestly, give us your thoughts on the interior and the systems as well as fit and finish? Very curious about the TD and how it performs. Wonder if it’ll move to any GM vehicle other than pickups or SUV’s?

    Reply
  4. I thought the Elevation editions were really slotted in between the Work Truck and the SLE. That was what GMC did for the last gen and the whole reason why I went with the SLE trim instead was because the elevation edition interior was really the work truck interior.

    Reply
  5. My 2019 GMC Sierra does not transfer texts to info center where it would read it to you like my 2017 did. I have to plug it into phone with cord to work. This is such a inconvenience.

    Reply
    1. Reply
    2. Old system was a clunky mess, new Android Auto or CarPlay is much better. And for 2021 I believe it becomes wireless.

      Reply
      1. It works perfectly for me on my 2016 Silverado 3500HD. Its all wireless and never have to plug in. Very Convenient.

        Reply
    3. I’ve actually stopped receiving texts in my 2017. Just within the last couple weeks. Phone calls still come through but no texts. Haven’t had time to figure out what’s up.

      Reply
  6. fuel numbers-gas vs. oil

    Reply
    1. hi
      I have the 2020 Silverado Double cab z71 RST with the 3.0 Duramax. Love the truck, had a 2010 Sierra the same configuration with the 5.3. Best mileage with the 5.3 was 19mpg. My worst mpg with the 3.0, doing mostly urban driving and around town was 24.9. The best on the open road is 33.4-34.1mpg. Only have 3000 miles in it and still not “broken in” and the 10 speed transmission is really smooth.

      Reply
  7. Not sure if it has the adaptive cruise, but if so, how does it work smoothly? Any concerns?

    Reply
  8. I have a 2015 GMC Sierra with a 5.3 pulling a 4000# aluminium fishing boat the engine works hard pulling constantly shifting in tow mode. How will this unit perform.

    Reply
    1. Which rear axle ratio does your truck have, the 3.08 or the 3.42?

      Reply
    2. That’s surprising since i have a 2012 5.3 LTZ on a 6spd and it pulls our 19ft fiberglass bowrider no problem. Less power, less torque, less gears, with 3.42 gearing.

      Reply
      1. Those 3.42 gears are key. The 3.08 equipped trucks are NOT for towing. As evidenced by the dismal sub 5k tow rating.

        I have a ’15 Sierra SLT with the 5.3/6L80E/3.42 combo. Tows my 4k boat/trailer combo with no problems at highway speeds. Even through the Appalachian Mountains last summer. Even managed ~13mpg doing it.

        Reply
        1. Yea but his 8 speed will help make the diff ratio less relevant versus my 6 speed for final drive

          Edit: or was the 6spd still used in his model year?

          Reply
          1. 2015 Sierra with the 5.3 would be paired to the 6-speed.

            Reply
  9. How do you plan on keeping the DPF clean. When the truck will never have to work hard enough to thoroughly to clean itself!!

    Reply
    1. The DPF keeps itself clean by way of the regeneration process that occurs once in a while. My 2016 Duramax 3500HD has 30,545 miles on it and I have never had a problem with it. I use it hard in the winter plowing but in the spring, summer and fall its just a commuter truck. No trailer towing or any hard work. 8-minute ride to and from work every day. No highway driving. It has a pretty leisurely life overall and the engine and truck has been very reliable and trouble free.

      Reply
  10. How much can the diesel tow compared to the 4×4 – 6.2 l L87. My travel trailer is 7900 lb. the owner manual for my 2010 GMC 1500 with a L9H states 12500 lbs . Will the Duramax 6 equipped 1500 even get close to my 2020 SLT

    Reply
    1. This isn’t a work horse engine. It’s a commuter and casual worker. Ford and Ram’s tow ratings on their 3.0 diesels is wayyy to adventurous.

      That 12,500lb figure for your 2010 1500 sounds wrong. With max tow and 3.73 gearing it should be closer to 10,000 I believe. And if you’re in the 80th percentile it’s time to get an HD.

      What size of truck is your 2020 SLT?

      Reply
  11. How does the diesel’s power compare with the 5.3 gas V8 in acceleration and passing?

    Reply
  12. I know you won’t get to do routine maintenance, but what are some anticipated costs, e.g. oil change, DEF usage, etc. Thanks

    Reply
  13. Ok has GM reinstated the text it was originally installed but put out a stop operating signal so text will NOT work WITHOUT a tether (hard wired).

    Reply
  14. Can you bring it up to the UP of Michigan, and I’ll pick up at Big Boy in St Ignace ? Enjoy!

    Reply
  15. I would like to know buyers suggestions.

    5.3 or the 3.0

    Is it worth the 5000$ up charge to get a little better gas milage.
    You would never make that 5k back in gas savings unless you kept it like 10 years or something.

    So why buy the 3.0 Diesel?

    Reply
    1. Now adays you don’t buy diesels in half tons and figure on recouping the cost because of fuel economy improvements, diesel fuel is too expensive, you would have to drive a serious amount of miles a year. You buy them because you want one, because you want to go a lot longer between fill-ups, because you like the smooth torquey delivery of the diesel, and because towing with them is usually a nicer experience than gas engines because of their power delivery.

      Reply
    2. This new 3.0 liter diesel is so smooth that I would gladly pay $5,000 more to drive this vehicle over a gas version.

      Reply
  16. How well does the engine/exhaust brake work, can you feel it hold back more than if it’s not engaged or is it so slight that only your imagination is telling you it’s on??

    Reply
  17. At what rpm does the engine turn while cruising at 65 and 70 mph? Just trying to get an idea how close peak torque is at highway speeds.

    Reply
  18. Max Towing capacity

    Reply
  19. Has GM placed a heater in the DEF tank that runs while parked? Either with a 110v plug-in cord or? In the northern tier of the US and Canada, where it really gets cold, it’s a big problem when DEF fluid freezes at 11 deg F. Sorry but we get to -25 deg F. This needs to be addressed!

    Reply
  20. Any Overheating issues on the 3L Dmax?

    Reply
    1. I have a fifth wheel of 8200 pounds ,is it a good buy for me

      Reply
  21. Diesel is more expensive to maintain, Oil & Filter changes, Fuel Filter changes, DEF, Diesel fuel more expensive than Gasoline. You would have to keep for many years to even have a chance to make up for the few MPG savings.

    Reply
  22. Tell us with the difference in GAS price vs Diesel price, Give a detailed price comparison on fuel cost vs the 6.2 engine, taken both MPG rating and the difference in cost of fuels. give us straight talk, please. Gas price averaging my area $1.39 and diesel is higher. bring out the old calculator and do a good analysis.

    Reply
  23. Hello to all
    In this enigmatical forthwith, I honey you all
    Esteem your one’s nearest and friends

    Reply
  24. I would like to know why there’s such a large difference in towing capacity between the 3.0 vs 5.3 when the torque rating’s are almost identical. I believe the number was around 3000lb. that’s a significant difference

    Reply
  25. I’ll try to answer what I can since I have been driving one since November.
    1. At 55MPH the RPMs are between 1300-1400; At 65MPH the RPMs are 1500; At 70MPH the RPMs are 1550. I also went up a Mississippi river bridge with the cruise set at 71 and never got above 1700 RPM. I don’t even think it down shifted.
    2. The add on for the diesel is 2495 at MSRP above the 5.3 with the Allstar pkg. 95% of LTs and RSTs are Allstar pkgs.
    3. I average 24-25MPG for every day driving. I got 554.9 mile out of my first tank. My best 50 mile average was 29.9.
    4. Acceleration is great and the 10spd is very smooth.
    5. The truck comes with a 3.23 gear and a 9300lb tow rating. There is an available diesel off-road pkg with a 3.73 gear and a 12000lb tow rating.

    I pull a 14′ trailer with a 850lb 4 wheeler for about 2000-2500lbs and bed completely loaded with ice chest, tools and gear. I get 17-18MPG running 75ish on the interstate. Compared to my previous truck (2015 5.3 with 3.42) I would get 10-11MPG with same load. I would get nearly same mileage with the trailer empty.

    To say this truck is a commuter is selling it short. I feel the truck is under rated. You’re at max torque at cruising speeds and it pulls effortlessly. The 6.2, which is a great engine, would have to be running at 4100 RPM to reach the same torque.

    As a side note, I can get 3000-3500 mile before needing to top off the DEF.

    Reply
  26. This is a fantastic power train. I have sold 5 of these 3.0 units. I order our new inventory and was leery at first. Some of my customers are pursing the mpg side of things and they have been very impressed. Not only with the economy but how smooth it is and having all that torque right off idle helps the off idle lag the 5.3 has. A couple of my guys haul trailers in the 7,000 to 8,000 ibs range. They report the 3.0 pulls hard and they were happy with its performance. The 10 speed doesn’t hunt for gears like the gas engines. So we are big fans of the power train. I have 35% of our inventory allocated to this power train. We are anxiously waiting for Gm to restart production. If you have not driven one do so. I think you will be very impressed.

    Best Wishes:
    Ron Rempel
    Janzen Gmc

    Reply
  27. Look at your headlights they are turning purplish you need a bulletin to get them fixed .GM needs to look into this problem so more of us can get them fixed

    Reply

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