Preview: 2015 Chevrolet Silverado/GMC Sierra

GM's heavy-duty pickups now look as good as they haul

PAYSON, ARIZ.?There are more trucks than cars out here in Arizona, and they?re all working hard. The hills are so steep, there are road signs warning drivers to turn off their air conditioning so their engines don?t overheat.

So I feel right at home in GM?s new heavy-duty trucks, the Chevrolet Silverado and GMC Sierra 2500 and 3500, which have been overhauled for 2015.

The greasy bits are still the same: the platform, suspension and engines carry over from the HD?s makeover in 2011, although with some steering tweaks that improve the handling.

The news is in the cab and cabin, which bring them in line with the all-new 1500 trucks that GM introduced for 2014.

That includes a vastly improved interior, a new infotainment system and safety warning programs, beefier exterior styling, improved cooling, and the simple but brilliant integrated bumper step for bed access.

The previous extended cab is replaced with a new double cab, which has front-hinged doors instead of two rear-hinged ones.

As in the outgoing 2014 HD trucks (and how odd it feels to write that when 2014 is barely a month old), the base powerplant is a 6.0-L V8 gasoline engine, producing 360 horsepower in the 2500 and 322 in the 3500, and 380 lb.-ft. of torque in both. It?s hooked to a six-speed Hydra-Matic transmission. A compressed natural gas (CNG) engine is also available.

The optional engine, and the only one I drove here, is a 6.6-L Duramax turbodiesel diesel rated at 397 horsepower and 765 lb.-ft. of torque, mated to an Allison six-speed automatic.

Although the Silverado and Sierra are mechanical twins, they?re now outfitted a bit differently. The price lists cover four pages, thanks to the various combinations of regular, double or crew cab (plus chassis cab for upfitters), three-quarter or one-ton, regular or dual rear wheels, and trim levels.

Basically, the Silverado ranges between $38,270 and $60,055, while the Sierra is $37,430 to $60,380. There?s also the ultra-luxury GMC Denali trim, which tops out at $68,645.

Those prices are for the petrol engine. The Duramax engine and Allison transmission are priced separately, at $9,670 and $1,445 respectively ? oddly enough, since you can?t order one without the other ? so tack on another $11,115 for the diesel. Which many people do, of course, for the towing and hauling capacity.

Full specs for all the configurations and axle ratios would take up half the Wheels section, but the top numbers are all that anybody ever advertises anyway.

For the 2500 models, that?s payload of 4,306 lb. (1,953 kg); conventional towing of 14,500 lb. (6,577 kg); and fifth-wheel of 17,900 lb. (8,119 kg). The 3500 increases that to payload of 7,374 lb. (3,508 kg); towing of 19,600 lb. (8,890 kg), and fifth-wheel of 23,200 lb. (10,523).

Ultimately, the Duramax engine and Allison transmission is a match made in heaven. Although Ford?s Power Stroke and Ram?s Cummins diesel engines are also very good, they don?t quite match the smooth power delivery of the GM trucks.

The company set up a comparison with Ford and Ram (the Japanese manufacturers don?t make heavy-duty models), taking identical 10,000-pound trailers up and down a 6-per-cent grade.

These demonstrations never make the competition look good, of course, but the Silverado had stronger acceleration uphill, even though its 765 lb.-ft. of torque was less than the 800 in the Ford and Ram. (GM?s reps said they?d matched the trucks as closely as they could, but there might have been some discrepancy in the axle ratios.)

But what really impressed me was the downhill test, where all three had the cruise control set to 88 km/h. GM integrates the cruise with the transmission and exhaust brake, which work together to maintain the set speed in spite of gravity.

The Silverado basically maintained its downhill speed on the steepest part, straying by only a couple of klicks over.

The Ram hit 104 km/h, while the Ford reached 112 km/h and would have gone faster if there wasn?t a curve coming up that forced me to use the brakes.

That feature makes towing far easier and confident, and saves wear-and-tear on the truck and trailer brakes.

The new interior is identical to that of the 2014 half-ton 1500 truck, with tons of storage, comfortable seats and, if so equipped, a large MyLink screen, with easy-to-use icons for stereo, navigation and other functions.

The trailer brake controller is up top and easy to reach. And I really like that if an option isn?t ordered, you get a different bezel instead of a blank button, which keeps everything looking smooth and neat.

On the other hand, I prefer Ford?s productivity screen, which lets you keep track of the mileage on various trailers when they?re hooked up.

And everyone should adopt Ram?s analog diesel exhaust fluid gauge. GM and Ford give you a digital warning when this necessary emissions fluid needs to be added, but I prefer being able to continually monitor it.

Still, the Silverado and Sierra?s restyling and new interiors, combined with underpinnings that were already very good, elevate this truck to a new level.

All of the heavy-duty competition has its good points, and its loyal fans, but in diesel form, I?d rate GM?s offerings as the current best-of-the-best.

Transportation for freelance writer Jil McIntosh was provided by the manufacturer. Email:

2015 Chevrolet Silverado/GMC Sierra 2500 & 3500

Price: $37,430 to $68,645

Engine: 6.0-L V8 gasoline/6.6-L V8 turbodiesel

Power/torque: 6.0: 360 hp (2500), 322 hp (3500), 380 lb.-ft. (both); 6.6: 397 hp, 765 lb.-ft.

Fuel consumption: N/A

Competition: Ford Super Duty, Ram Heavy-Duty

What?s best: Engine/transmission combination, quiet cabin, towing performance.

What?s worst: Expensive diesel engine.

What?s interesting: Trailer sway control standard on all models, including 3500 dually.

  • Preview: 2015 Chevrolet Silverado/GMC Sierra 2015 Chevrolet Silverado Heavy-Duty - photo by Jil McIntosh - for Wheels
  • Preview: 2015 Chevrolet Silverado/GMC Sierra 2015 Chevrolet Silverado LTZ trim Interior - photo by Jil McIntosh - for Wheels
  • Preview: 2015 Chevrolet Silverado/GMC Sierra 2015 Chevrolet Silverado 3500 Crew Cab LTZ dual-wheel - photo by Jil McIntosh - for Wheels
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