The 2015 GMC Sierra HD family has been completely revitalized and reenters the heavy-duty fray with mucho gusto. Payload hits a maximum, (and best in class), 7,374 pounds. The GMC HD has a best in class conventional tow rating of 19,600 pounds, which is mighty impressive. Maximum fifth-wheel trailer(ing) rating is a robust 23,200 pounds, but not best in class.
The GMC Sierra HD, and its Chevrolet Silverado HD brethren, intend to turn heads with their new design both internally and externally; however, it’s the power that most consumers want to hear about first:
The Vortec 6.0L gas V-8 with variable valve timing is matched with the Hydra-Matic 6L90 six-speed automatic transmission as the standard powertrain across the Sierra HD model range. This combination is engineered to deliver excellent performance and efficiency, especially at low-rpms. It is rated at 360 horsepower (268 kW) and 380 lb-ft of torque (515 Nm) in 2500HD models and 322 horsepower (240 kW) and 380 lb-ft (515 Nm) in 3500HD.
The 6.0L engine is also available in a bi-fuel model that features special hardened valves and valve seats that enables it to run on compressed natural gas or gasoline. The CNG fuel system is installed by a GM supplier and completed vehicles are delivered directly to the customer, making the purchase process as seamless as ordering any other option.
The Duramax 6.6L diesel and Allison 1000 six-speed automatic transmission powertrain combination is available on all 2500HD and 3500HD models, with highlights that include:
• 397 horsepower (296 kW) at 3,000 rpm
• 765 lb-ft of torque (1,037 Nm) at 1,600 rpm
• High-pressure (30,000 psi/2,000 bar) Piezo-actuated fuel system for greater fuel efficiency, improved performance and reduced emissions
• Variable vane turbocharger that also acts as an exhaust brake to help control or slow the vehicle’s speed
• Selective catalytic reduction after-treatment system using diesel exhaust fluid injection to provide the best overall diesel characteristics and performance – with a range of about 5,000 miles (8,000 km) between DEF refills
• Combustion and after-treatment optimized to provide about 700 miles (1,125 km) between diesel particulate filter regenerations
• B20 biodiesel capability for an alternative fueling option.
The Allison 1000 features driver shift control with tap up/tap down shifting and a patented elevated idle mode cab warm-up feature. Also, the tow/haul mode reduces shift cycling for better control and improved cooling when towing or hauling heavy loads.” General Motors Media
Gas engines for the 2015 GMC Sierra HDs will be offered stock and with a bi-fuel option. This will combine the gas engine with compressed natural gas (CNG). Duramax diesel engines will be offered as well. The diesel engines are rigged to run on B20 (bio-diesel) if desired.
“Forget the notion that heavy-duty trucks are basic tools with a trailer hitch,” said DiSalle. “The 2015 Sierra HD trucks can haul the heaviest load with unmatched comfort and technology that make the job easier.”
Additional new and enhanced features for the 2015 Sierra HD lineup:
• CornerStep rear bumper, EZ Lift and Lower tailgate, standard upper tie-downs and other features that make cargo handling easier
• Standard StabiliTrak with Trailer Sway Control on all models, including 3500HD dually
• Integrated cruise control, auto grade braking and diesel exhaust braking (diesel models), for greater driving control and reduced brake wear on grades
• Enhanced cooling airflow, which enables the Duramax turbo diesel and 6.0L gas engine to better maintain full power, even under heavy loads and high ambient temperatures
• Latest-generation IntelliLink infotainment system, which offers a variety of connectivity options for devices of all types and available navigation” – – General Motors Media
I’m a big fan of General Motors’ engines and I look forward to putting the 2015 GMC Sierra HD fleet to the test.
Check out this TFLtruck reveal video of the 2015 Sierra HD and Silverado HD:
Here’s more technical info!
Models: GMC Sierra 2500HD and 2500HD Denali; 3500HD and 3500HD Denali
Construction: body on frame
Manufacturing locations: Fort Wayne, Ind., and Flint, Mich.
6.0L VVT V-8 – gas/E85 or bi-fuel Duramax 6.6L turbo-diesel
Engine type: OHV gasoline or bi-fuel V-8 with variable valve timing OHV turbo-diesel with Piezo-actuated fuel system and variable-vane turbo
Horsepower (hp / kW @ rpm): 360 / 268 @ 5400 (2500HD)
322 / 240 @ 4400 (3500HD) 397 / 296 @ 3000
Torque (lb-ft / Nm @ rpm): 380 / 515 @ 4200 (2500HD & 3500 HD) 765 / 1037 @ 1600
Transmission: Hydra-Matic 6L90 6-speed auto. Allison 1000 6-speed auto.
Final drive ratio: 4.10 or 3.73 3.73
Chassis / Suspension & Brakes
Front: long- and short-arm independent front torsion bar suspension
Rear: semi-elliptic two-stage multi-leaf spring
Steering type: integral power-assisted recirculating ball
Brakes: power-assisted brake-apply, four-wheel disc, four-wheel ABS
Wheel and tire size: 17 x 7.5-in. / LT245/75R17 or LT265/70R17
18 x 8.0-in. / LT265/70R18
20 x 8.5-in. / LT265/60R20
Long Box Double Cab Standard Box Double Cab
Long Box Crew Cab Standard Box Crew Cab Long Box
Wheelbase (in / mm): 133.5 / 3393 144.1 / 3662 158.1 / 4017 153.7 / 3904 167.6 / 4259
Overall length (in / mm): 224.3 / 5699 230 / 5841 248.8 / 6321 239.5 / 6083 258.4 / 6563
Overall width (in / mm): 80.1 / 2035 80.5 / 2045 80.5 / 2045 80.5 / 2045 80.5 / 2045
Overall height – 2WD: (in / mm): 77.8 / 1976 78.1 / 1984 77.9 / 1978 78.3 / 1988 78 / 1981
Overall height – 4WD: (in / mm): 77.7 / 1975 78 / 1983 77.8 / 1977 78.3 / 1987 79.9 / 1980
Regular Cab Double Cab Crew Cab
Headroom (in / mm): 42.8 / 1087 front: 42.8 / 1087
rear: 38.7 / 982 front: 42.8 / 1087
rear: 40.5 / 1029
Legroom (in / mm): 45.3 / 1150 front: 45.2 / 1150
rear: 34.6 / 880 front: 45.3 / 1150
rear: 40.9 / 1040
Max payload (lb / kg): 4306 / 1953 7374 / 3508
Max conventional trailing (lb / kg): 14500 / 6577 19600 / 8890
Max 5th wheel trailering (lb / kg): 17900 / 8119 23200 / 10523