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GM Authority

Is Another Transmission Option Coming For The Chevrolet Silverado Medium Duty?

As we reported previously, the all-new 2020 Chevrolet Silverado HD and 2020 GMC Sierra HD brought a new gasoline engine option into the fold, namely the 6.6L L8T V8, which arrived as a replacement for the outgoing 6.0L L96 V8. Then, earlier this month, Chevrolet Commercial announced it would offer the 6.6L L8T with the 2021 model year for the Chevrolet Low Cab Forward Truck. Nevertheless, the engine is still conspicuously absent from the one truck which arguably needs it the most – the Chevrolet Silverado Medium Duty line. The question is, why? Well, it’s possible that it all comes down to the transmission.

Up until now, the 6.6L L8T V8 has exclusively paired with the MYD 6L90 six-speed automatic transmission, which is limited to a 15,000-pound GVW, or 21,000-pound GCW. And while specs like that are perfectly adequate for the Chevrolet Silverado 3500HD chassis cab, GMC Sierra 3500HD chassis cab, or 3500/4500HD Low Cab Forward truck, they simply wouldn’t be up to task with the Chevrolet Silverado Medium Duty truck line.

That said, it’s possible that General Motors is currently waiting to launch the 6.6L L8T on the Chevrolet Silverado Medium Duty truck line in order to develop a new transmission that’s more robust than the current MYD 6L90 six-speed automatic. Something like an Allison 1000 or 2000 would certainly do the job nicely.

GM L8T V8

To note, the 6.6L L8T V8 gas engine produces 350 horsepower and 425 pound-feet of torque when equipped in the Chevrolet Low Cab Forward truck. Found under the hood of the 2020 Chevrolet Silverado HD and 2020 GMC Sierra HD, the ‘eight produces 401 horsepower and 464 pound-feet of torque, an increase of 41 horses and 84 pound-feet when compared to the outgoing 6.0L L96 V8.

Would you like to see the 6.6L L8T V8 gas engine in the Chevrolet Silverado Medium Duty truck line? Let us know your thoughts in the comments, and make sure to subscribe to GM Authority for more Chevrolet Silverado news, Chevrolet news, and around-the-clock GM news coverage.

Jonathan is an automotive journalist based out of Southern California. He loves anything and everything on four wheels.

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Comments

  1. I hope they can do it quickly.

    A gas option would really push this already popular medium duty rig to the next level.

    The 22.5” wheels and the dock height model is needed too with a 26,000 lb GVWR option.

    Reply
    1. I agree that a gas option is needed. With the proper gearing, it would be a great addition to the medium duty line.

      Reply
    2. No gas option and more than likely won’t but the 6500 offers 22.5″ tires with 26,000 GVWR.

      Reply
  2. While the 6.6L gas would be a welcome option, I want the big block 8.1L back. That engine is 10+ years old and is still a beast.

    Reply
  3. The larger corporations particularly when converting to L.P. gas like the gas company are going to insist on gas engine. uhaul and others would never spend the additional money on diesel. If g m want s to gain the market place they have no other choice.

    Reply
    1. I agree with Mr. Younker about the need for a gas engine. That said, until the upgrade to an electric motor for the medium duty segment.
      Personally, I am looking to upgrade my old 08 Ford 350 dually diesel for pulling my 18,000 lb. 5th wheel trailer. The electric option is more my speed, since road tractors have already been upgraded to electric by my reading on the net.

      Reply
  4. That 6.6 gasser is to small for the medium duty and would be gutless put the 8.1 with 450hp/550tq and with a 6 speed manual transmission would be perfect

    Reply
    1. Too small? Are you high or just dumb?

      These are medium duty trucks (up to class 6) and the L8T is exactly what the MD needs. You must have no clue how these trucks are used. Not everyone needs or wants a diesel.

      Reply
  5. Until they bring back a three pedal truck (won’t happen) I’ll keep running the old stuff.

    Reply
    1. Theres a very obvious choice, the new 9sp allison automatic which is replacing the old 6spd 1000/2000 series. This transmission could work for both the L8T and the duramax diesel likewise. As for a manual the long out of production new venture NV5600 might have been ideal , there is also a 7 spd Eaton mid range type.

      Reply
  6. Honestly a medium duty eaton manual would be a perfect option for both the gas and diesel engines. I drive one of these for work every day and the automatic leaves something more to be desired

    Reply
    1. What does the automatic leave to be desired?

      All of these trucks are in commercial fleets. Less than 2% desire a manual, and all the additional responsibility that a manual brings. If manuals are gone for personal use trucks, they sure as he11 are gone for commercial trucks.

      Reply
  7. How about use the 10 speed allison behind the 2500/3500 duramax for all 6.6 gas/diesel engines?

    Reply
  8. Not actually an allision… I wish they would stop calling it that. It may be a good transmission or even a great one. But an allison it is not. Just a mash up of Ford and GM.

    Reply
    1. Does anyone know the difference between the two 10 speeds. Is the one certified by Allison better or is it just a marketing thing?

      Reply
  9. I think this engine and a 8speed Allison would propel them in the class a and c motor home division.

    Reply
  10. It all comes down to the deneroes

    Reply
  11. How about a 8.1 stroke and a 396 bore with long rods and put a 13 speed roadranger behind it. Would be about 450 cubes and a torque monster put light pistons in it and would wind very well also. Even if the 13 or 18 speed was autoshify. Don’t offer anything except air brakes either. Make them real trucks. I would think a 13 or 18 speed would kick total ass behind a DuraMax. Air brakes are so much more reliable and even have a real parking brake too. Auto shift anyone can drive. Problem is dipstick engineers and bean counting dipshits combined with retarted management will not build the best they can.

    Reply
  12. I agree, they need a gas V8 option. I live in Portland, Oregon and have not seen a single one of the new mediums. The Top Kick and Kodiaks were popular here. I think customers here have gone to Ford and Navistar and are reluctant to trust GM to continue with mediums after dropping them in 2009.

    Reply
  13. The big problem really is that very few g m dealership s offer service particularly outside urban areas in Illinois. The joint venture with Navistar / International I would of thought they would offer service on the G m products after calling and speaking to the service manager at the Navistar International truck center Thompson truck franchise of International dealerships they said that they would Not offer service on the G m product line. Makes no sense considering that the chassis is Navistar / International and the cab and drive train is G m. What a miserable situation for service…… G m better consider this item before major issue s are costing them reputation and headache s… How could this be an oversight sevice is apart of the entire experience of ownership and the ability to market a product.

    Reply
  14. Forget the automatic transmissions this truck NEEDS A MANUAL need I say more? If they offered them in a manual transmission they would sell quite a bit. There’s quite a bit of people out there that would rather buy a brand new truck with a manual transmission. I would go and spec one out in a New York minute if they offered them in a manual.

    Reply
  15. Electric will be out in just a few years and gas will be obsolete but diesel will remain for long drives. Who wants to stop every 150 miles to charge? The Allison transmission is an Allison with Ford having nothing to do with Allison transmissions.

    Reply
  16. Honestly I see CNG replacing diesel long before gasoline is obsolete in smaller trucks. Already starting in California, I haven’t seen a new diesel trash truck, school bus, or transit bus in years.

    Reply
  17. CNG or electric is not A very good common denominator in the medium duty out here on the east coast their isn’t many CNG or electric stations here and non forecasted in the immediate future. You are sol if you have one just motorhome dealership s are about the only fill stations for CNG and I only seen a couple of charging stations for electric..

    Reply
  18. I’m in the market for a new truck and want to gm and I think the l8t would be a good thing I have a small landscape business and don’t want or need a diesel the duramax is a very good engine but again I can’t justify having it I’ve owned GM’s for 40 year’s and would like to keep it that way

    Reply
  19. Hi

    I am Mr ALEX from NEW YORK.
    I want to know if you ship to NEW YORK

    Hope you also accept master, visa or american express credit card.
    Waiting for your reply as soon as possible.

    Regards
    ALEX ALI
    786-749-6550

    Reply

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