By on October 7, 2016

2017 Chevrolet Silverado HD, Image: © 2016 Matthew Guy/The Truth About Cars

At the end of September, some of my auto journo colleagues busied themselves with the French delights of Paris, covering new reveals at the Paris Auto Show.

Me? I was somewhere much more in line with my personality, surrounded by heavy-duty trucks at the 1.5-mile Texas Motor Speedway. With both Ford and Ram cresting the 900 lb-ft of torque mark, the General needed to play catch-up.

Enter Chevy’s new 6.6-liter Duramax Diesel.

Over the last few months, GM made a lot of noise about the upcoming changes to its Duramax diesel-powered trucks, going so far as to tease us with clandestine shots of hood scoops and big badges.

Not unlike the horsepower wars of the ’60s, the Detroit Three are locked in a battle for truck supremacy, with sky-high torque figures and braggadocious power claims. For 2017, Ford advertises 925 lb-ft of torque for its 6.7-liter PowerStroke while Ram beats its chest by claiming an even 900 lb-ft out of its 6.7-liter Cummins. GM’s previous 6.6-liter Duramax made 765 lb-ft, but the new-for-2017 version, also 6.6-liter, slots neatly between its competitors at 910 lb-ft.

Using the measure of torque, this revised Duramax falls a bit short of the top step, but there’s more to it than that. GM’s engineers and marketers spoke a lot of “claim trucks” and how GM has consciously decided to focus on the driving experience as a whole and not chasing mythical marketing numbers. Make what you will of that statement, but GM estimates Fiat Chrysler Automobiles sells only about 500 Rams per year equipped to tow 30,000 pounds or more, a figure promoted heavily in Ram advertisements. GM is intent on building a comfortable and capable truck that’s better equipped to handle the demands tossed at it by real-world drivers. In other words, GM isn’t building a truck to haul marketing and advertising fodder.

2017 6.6-liter Duramax Diesel, Image: © 2016 Matthew Guy/The Truth About Cars

At Texas Motor Speedway, my seat time was divided between two different experiences: a drive on the oval’s apron in a black High Country 3500 dually and a two-lap sprint through a short infield track in a white LTZ three-quarter ton.

The immediate first impression was a distinct lack of traditional diesel clatter. GM claims a 38-percent reduction in idle noise — and I believe it. The Duramax deploys a common-rail direct injection fuel system with new high-capability solenoid-type injectors, producing a sky-high fuel pressure of 29,000 psi. This makes for a cleaner fuel burn, which results in reduced particulate emissions. The new injectors support up to seven opportunities for fuel delivery per combustion event and contribute to reduced diesel clatter. A new, two-piece oil pan along with foam-covered valve covers also aids in this lack of din. This is a quiet truck.

Eager to not cause damage to the racing surface that’ll host NASCAR’s Texas 500 on Nov 6th, Chevy’s engineers limited us to the flat apron of the track below the white line. Fine by me. I had no desire to find out what physics thinks of drivers who take a one-ton dually truck with a 10,000-pound trailer in tow at full tilt into 24 degrees of banking, nor did I care to replicate the wreck in turn one of lap one during NASCAR’s first outing here in 1997.

To pit road, then, where we lined up our test trucks single file for a full throttle launch. From a standstill in Tow/Haul mode, the dual rear wheels of the sumptuously leather-lined High Country fought for traction off the line with 10,000 pounds attached to a standard two-inch trailer hitch. The 445 horsepower and 910 lb-ft of twist had no trouble getting the Silverado to 60 miles per hour in the 800 feet afforded by an empty pit lane.

Exiting the pits, we roared into turn one and coasted down to 40 mph before nailing the throttle once again to bring the truck up to 70 mph on Texas Motor Speedway’s 1330-foot backstretch. This was a good test of highway passing power with a load in tow. Encouraged by the jocular Chevy engineer sitting alongside, I again circled the track and walked on the loud pedal a second time for the length of pit road.

2017 Chevrolet Silverado HD, Image: © 2016 Matthew Guy/The Truth About Cars

The Silverado HD’s acceleration was free of drama, holding itself straight and true during the launches and rolling starts. GM seems to have programmed the electronic nannies to permit just enough of the aforementioned wheelspin so the burly Duramax doesn’t come out of boost and bog the launch. Reinforcing the stereotype that everything’s bigger in Texas, the Silverado HD has pedal travel longer than a cross-country cattle drive.

Braking from these velocities was a stable and confident experience with the integrated trailer brake controller locked into an appropriate setting. The integrated exhaust brake system creates added back pressure in the exhaust, resulting in negative torque during deceleration events. While Texas Motor Speedway is bereft of hills, I can only presume the increased negative torque will also help with downhill driving. It was here that GM’s exhortations of “not chasing the numbers” and “real-world customers” rang in the back of my head. Sure, it’s great to have bragging rights, but 1000 lb-ft of torque won’t do ya no good when you’re upside down at the bottom of a steep hill tangled up in your own trailer.

Navigating the sinewy TMS road course in an unloaded Silverado 2500 LTZ revealed typical HD truck fare; no one expects a Miata here. It’ll do fine duty for the folks who rarely tow, but rather use their trucks for the daily office commute. It was an odd experience, as approximately 0 percent of buyers will autocross their Heavy Chevy, but the exercise underscored GM’s chassis work. The 2017 HD trucks are a full 1-percent heavier than last year, yet — for comparison — crank out 12-percent more horsepower and 19-percent more torque than their predecessors. The math works. These things aren’t slow. Unladen, 60 mph arrives in 7.1 seconds, a full seven-tenths quicker than numbers posted by GM’s 2016 models.

GM teased us with photos of the hood scoop for months ahead of this reveal, and it’s indeed a functional unit. Its choice to integrate a scoop on the hood can be summed up in one word: cool — as in cool looks and cool air.

2017 Chevrolet Silverado HD Hood Scoop, Image: © 2016 Matthew Guy/The Truth About Cars

Getting access to cool, dense air is an engine’s Holy Grail and the top of the hood is a logical spot to get it. The radiator, bumper or superfluous fog lights are all in the way in other spaces. GM’s solution was to devise a system to shovel atmosphere though the structure of the hood and into the same pipe that delivers air from the fender-mounted intake. Yes, Virginia, there is still a fender-mounted intake, which is said to deliver about 45 percent of total airflow.

2017 Chevrolet Silverado HD Fender-Mounted Intake, Image: © 2016 Matthew Guy/The Truth About Cars

2017 Chevrolet Silverado HD Fender-Mounted Intake, Image: © 2016 Matthew Guy/The Truth About Cars

Hailing from a climate in which what falls from the sky is not to be believed, I naturally asked about snow accumulation on the scoop. With about half of the air coming from the fender mounted intake, Chevrolet engineer Tom Dye stated he has no concerns about the Duramax gasping for air upon startup and, despite extensive testing, has not seen any snow in the airbox yet. Good enough, then. An ambient temperature of -20° F was GM’s target for cold-weather startup without a block heater.

Nevertheless, GM did engineer a gravity-based solution for any errant debris or weather that does happen to make its way past the scoop’s intake. A separator is designed to trap fine dust and snow, taking out moisture and collecting it in the underhood bulge you see in the pictures below.

2017 Chevrolet Silverado HD Underhood Debris Trap, Image: © 2016 Matthew Guy/The Truth About Cars

There’s a flat, squeezable nipple (insert crass joke here) meant to collect and automatically release any water that’s collected. Heat should melt what little snow comes in. The nipple is made of rubber and designed to open on its own, using gravity to drain and drop its collection of water down through an open spot between the engine and chassis, which is likely to be wet already. Alert readers will note this system’s proximity to underhood electrical components. When I mentioned this, I was assured by engineers that GM has run thousands of hours of testing and determined it not a problem. The nipple can also be rotated counter-clockwise and completely removed to dump out any random big bits that make their way in through the scoop, such as the scattered leaf. Nipple.

The diesel exhaust refill point remains underhood and accepts 7 gallons. Diesel exhaust fluid (DEF) consumption has increased a bit; as emissions go down, DEF consumption goes up. Engineer Dye stated a relocated DEF filler is high on his wish list. It likely remains underhood in this Duramax iteration because it would be costly to move, given GM would have to make a new stamping for the fuel filler neck. It is this author’s opinion that choosing to spend development dollars elsewhere was a sensible move.

GM’s revised 6.6-liter V8 Duramax provides more performance in a very familiar package. Forgoing the temptation to beat its competitors over the head with torque figures, GM has allowed itself to improve its heavy-duty offering on a host of fronts, from racket-at-idle to braking performance. It’ll take a longer drive to fully experience all of its virtues and faults, but initial impressions tell of a refined and quiet truck that’ll have more than enough grunt for 95-percent of the consumer market. As GM was wont to remind us, it’s not all about that final torque number.

Here’s a quick poll for you, B&B: which automaker will be the first to reach the mythical 1000 lb-ft figure? Will it be FCA and its penchant for all things loud and extroverted? Will it be Ford and its unending quest to vanquish cross-town rivals? One thing’s for sure: it won’t be GM. Given its rationale for focusing on the driving experience instead of the numbers, I can’t say that’s a bad thing.

[Images: © 2016 Matthew Guy/The Truth About Cars]

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35 Comments on “2017 Chevrolet Silverado HD First Drive – More Than Just Numbers...”


  • avatar
    Lou_BC

    GM on paper at least had the “weaker” HD truck but always does well in HD shootouts. I’d like to see a comparison of torque/hp graphs. 10k trailer isn’t much of a test for these beasts but GM states that is the average tow weight for HD’s. It makes sense since many jurisdictions require a drivers licence endorsement for any weight much past 10k. In BC it is 4600 kg or 10,120 lbs.

    GM claims to have made the hood scoop so it doesn’t suck in snow but what about the typical lazy driver stumbling glassy eyed to his truck for the morning commute and there is a foot of snow on the hood? I’ve seen it too many times. A gun slit cleared spot for the moron to see out of and off they go.

    CAPS LOCK FOR 1ST POST…… HA HA

    • 0 avatar
      RobertRyan

      @Lou_BC
      Is that an endorsement or do they need an extra test?

      • 0 avatar
        Lou_BC

        RobertRyan ???? a few laps around a track doesn’t prove a thing. I could lay out a very long test including gravel roads to really test how composed these beasts are under load.

    • 0 avatar
      mason

      The 2013+ Rams have what they call the Ram Active Air intake system and is controlled by the ECU. The system draws cooler air from the front of the vehicle when it senses extreme heat, it also engages at high altitudes for better throttle response. When conditions are wet, the system closes the CAI off and pulls air from the inner fender well. It’s a very seamless operation and I’m sure GM’s version operates in similar fashion.

  • avatar
    ajla

    “a distinct lack of traditional diesel clatter.”

    Lame. If I’m shelling out for a diesel truck I want it to sound like a Peterbilt.

    • 0 avatar
      fincar1

      …or to be mistaken for the UPS guy….

      • 0 avatar
        indi500fan

        My UPS guy’s truck is a gasser these days. I wonder if this is an indicator that the lowest total lifecycle cost is no longer diesel in the medium weight market? I know UPS is very good at tracking costs.

        • 0 avatar
          Scoutdude

          You are correct that UPS switched to spark ignition because it had a projected lower life cycle cost than diesel. Some of those spark engines do run on gasoline while others use LNG. Now UPS is putting a fair number of EVs into services as well as Range extended EVs using the BMW REx. For the bigger trucks they are going LNG.

          • 0 avatar
            indi500fan

            When you look at the internal changes for emissions (massive egr and lowered compression ratios) and complexity of the diesel after treatment package, it’s reasonable to me that gasoline and nat gas are strong competitors on lifetime costs.

    • 0 avatar
      indi500fan

      You’ll need to ratchet back a good many model years. When diesels went to common rail, things quieted down a bunch. Maybe to a Ford 7.3 or a Dodge 5.9.

      • 0 avatar
        JimZ

        the 7.3 was incredibly loud at first, then they went to “split shot” injection which cut the racket a little. The 6.0 also raised a ruckus.

        I’m with you, though, they’re *too* quiet now. They don’t have to be deafening like a 53-series Detroit Diesel, but a little bit of clatter up there to say “hey, I’m workin’ here!”

        • 0 avatar
          dal20402

          Driving our ill-fated 7.3 cutaway buses was an exercise in auditory torture by the end of a 10-hour shift.

          Real buses with real engines (Cummins M11 and ISL, and even the awful Caterpillar C9) were far easier on the ears, because the engines were further away and not much (if any) louder.

    • 0 avatar
      BigOldChryslers

      +1
      I liked the sound of my ’94 Cummins. My ’07 Cummins (5.9, not a 6.7) which reaplaced it is too quiet. I wish I could program the ECU to reduce the number of injection pulses per firing event. That should put some of the clatter back in, and the injectors would probably last longer too.

    • 0 avatar
      NoGoYo

      I want that old Cummins with a drainpipe exhaust sound.

      So exhilarating!

      • 0 avatar
        Lou_BC

        Agree. There should be some diesel clatter there. My dad had Mack trucks. I miss that sound. I don’t recall them being as “clattery” as pickup truck engines. Must be true, nostalgia filters out the rough edges.

        • 0 avatar
          NoGoYo

          I remember some website I read describing the old Mack R diesel growl as resembling that of a bulldozer. I believe it.

          • 0 avatar
            Lou_BC

            NoGoYo – I remember Mack having what they called “Maxidyne” and “Thermodyne” engines. The Maxidynes were newer and had lower rpm peak torque figures and a broader torque band. They were all turbocharged. My dad had the Maxidynes in his R model Macks and the Thermodynes were in his B Model Macks. The Maxidyne R model was super easy to drive. I cut my teeth on R model Macks. He had sold the B models by the time he’d let my brother and I drive them.

  • avatar
    CoreyDL

    This review is a bit sub-par in quality compared to your normal reviews (which I enjoy). So many overly wordy sentences made it hard to get through.

    • 0 avatar
      bumpy ii

      Truck. Mwraaaaaaaaawr.

    • 0 avatar
      Adam Tonge

      The problem is that these kinds of events don’t lead to the type of review you want.

      • 0 avatar
        28-Cars-Later

        Truck, truck, truck, truck, truck, buy, truck, truck, truck, truck, truck, want, truck truck ‘Murica.

      • 0 avatar
        CoreyDL

        Why not? Mark went to one and it turned out fine for the Titan XD.

        • 0 avatar
          Adam Tonge

          I went to a Ford event and was able to get a story out of it. However, I don’t think I could have gotten a story out of the drives I did. I drove the F150 with new 3.5TT and new 10-speed. It was nice. Can I write 1200 words about it? Not 1200 words that would mean anything to you. Renting a Home Depot trucks and throttling the bejesus out of it for a few hours tells you more about a truck than a few laps.

          Matthew is a better writer than I am and his event was probably better. Still, I think towing on a closed course has it’s limitations in a review.

  • avatar
    cdotson

    The “nipple” you enjoy discussing so much is actually called a duckbill valve. They’re common on cyclonic air filter housings to purge dust separated from the air stream before the filtration media. The natural pulsations in combustion engine airflow cause the valve to pulsate during operation making them largely self-clearing.

  • avatar
    JimZ

    the full size Transit van has duckbill valves underhood also.

  • avatar
    mfgreen40

    I have seen the duckbill drain fail to open on a Cadillac air cond. system and soak the carpet so they are not fool poof.

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