The 2026 GMC Sierra 3500HD is 250.8 inches long, 81.9 inches wide without mirrors and 81.2 inches tall on a Crew Cab Standard Bed configuration, with a 36.0-gallon fuel tank and a curb weight of 7,417 pounds on a Crew Cab 4WD AT4. Allen Tillery serves Sierra 3500HD shoppers across Hot Springs, Arkadelphia, Hope, Bryant, Little Rock and Nashville, plus Saline County and Hot Spring County. See the Sierra 3500HD Overview for pricing and trim positioning, or the All Trims Compared page for a full trim-by-trim breakdown.

Engine Specifications

Engine	Horsepower	Torque	Transmission	Availability
6.6L V8 Gas (L8T)	401 hp	464 lb-ft	Allison-built 10-speed automatic	Standard, Pro through Denali
6.6L Duramax Turbo-Diesel V8 (L5P)	470 hp	975 lb-ft	Allison-built 10-speed automatic	Available, Pro through Denali; standard on Denali Ultimate

Exterior Dimensions

Dimension	Measurement
Overall length, Crew Cab Standard Bed	250.8 in.
Overall length, Crew Cab Long Bed	266.7 in.
Width without mirrors	81.9 in.
Height	81.2 in.
Wheelbase, Crew Cab Long Bed	172 in.
Minimum ground clearance, Pro/SLE/SLT/Denali/Denali Ultimate Crew Cab	10.4 in.
Minimum ground clearance, AT4 Crew Cab	11.1 in.
Turning diameter, Crew Cab	57 ft.

Configuration	Curb Weight
AT4 Crew Cab 4WD Standard Bed	7,417 pounds

Curb weight, wheelbase, length and ground clearance all vary by cab, bed and drivetrain configuration; the figures above are for specific Crew Cab builds. AT4's off-road suspension raises its ground clearance over the other Crew Cab trims.

Interior Dimensions

Measurement	Front	Rear
Head room	43.0 in.	40.1 in.
Leg room	44.5 in.	43.4 in.
Shoulder room	66.0 in.	65.3 in.

Every Crew Cab configuration seats 5.

Capacity and Capability

Rating	Maximum	Configuration
Fifth-wheel/gooseneck towing	36,000 lbs	Regular Cab Long Bed 2WD DRW, Duramax, Max Trailering Package
Conventional towing	20,000 lbs	Crew Cab Long Bed 4WD DRW, Duramax
Gross Combined Weight Rating	43,900 lbs	Regular Cab Long Bed 2WD DRW, Duramax, Max Trailering Package
Standard payload	4,089 pounds	AT4 Crew Cab 4WD Standard Bed
Standard bed length	82.2 in.	AT4 Crew Cab configuration
Long bed length	8 ft.	Crew Cab Long Bed configuration
Bed volume	76 cu ft.	Crew Cab Long Bed configuration

Every stated maximum above requires the truck be properly equipped in the exact configuration listed. GMC's Gooseneck / 5th Wheel Prep Package and integrated trailer brake controller are available across the lineup.

Wheels, Tires, and Brakes

Trim	Wheels
Pro / SLE / SLT (base)	20-inch painted alloy wheels, all-terrain tires
AT4	20-inch gloss-black aluminum wheels, available BFGoodrich off-road tires
Denali / Denali Ultimate	20-inch Ultra-Bright machined aluminum wheels with chrome or gloss-black inserts

Four-wheel antilock disc brakes are standard across the lineup.

Fuel Economy and Range

Fuel tank capacity is 36.0 gallons across the lineup. The 6.6L V8 runs on regular unleaded gasoline; the Duramax Turbo-Diesel runs on diesel. Both engines are engineered around heavy-duty towing capacity rather than fuel economy.

Key Features by Trim

Feature	Pro	SLE	SLT	AT4	Denali	Denali Ultimate
13.4-inch infotainment with Google built-in	S	S	S	S	S	S
Dual rear wheel option	O	O	O	not std	O	O
Duramax Turbo-Diesel	O	O	O	O	O	S
Heated and ventilated leather front seats	not std	not std	not std	S	S	S
Off-Road Suspension Package	not std	not std	not std	S	not std	not std
Power sunroof	not std	not std	not std	not std	O	O

S = standard, O = available, "not std" = not standard equipment on that trim. See the full trim-by-trim breakdown for everything each trim adds.

Safety and Compliance

Standard safety equipment includes forward collision alert, automatic emergency braking, rear cross-traffic alert, an integrated trailer brake controller, and a StabiliTrak electronic stability control system with trailer-sway control. Adaptive cruise control with trailering is available on AT4 and above.

Warranty Coverage

Coverage	Term
Basic (bumper-to-bumper)	3 years / 36,000 miles
Powertrain, gas engine	5 years / 60,000 miles
Powertrain, Duramax diesel	5 years / 100,000 miles

See the Sierra 3500HD Service and Maintenance page for intervals and ownership costs.

What These 2026 Sierra 3500HD Numbers Mean in Practice

Spec	What It Means
81.9 in. wide without mirrors	Fits most standard garage bays, but check mirror-to-mirror width against your specific door opening before pulling in.
250.8 in. long (Crew Cab Standard Bed)	Roughly 21 feet: plan for a full-size parking space or a driveway with room to swing wide on turns.
36,000-lb gooseneck maximum	Reached only on a DRW Regular Cab with the Max Trailering Package. A Crew Cab SLT will tow well under that figure.
82.2-in. standard bed	Fits a standard pallet lengthwise with room to spare; a long bed adds roughly 16 more inches for bulkier loads.

Specifications FAQs

How long is a 2026 GMC Sierra 3500HD?

250.8 inches on a Crew Cab Standard Bed configuration. Regular Cab and Double Cab lengths vary by bed choice.

How much does a Sierra 3500HD weigh?

Curb weight varies by cab, bed and drivetrain; an AT4 Crew Cab 4WD Standard Bed weighs 7,417 pounds. GVWR ranges from 10,950 to 14,000 pounds depending on configuration.

What is the fuel tank capacity?

36.0 gallons across the lineup.

What is the wheelbase of a Sierra 3500HD?

172 inches on a Crew Cab Long Bed configuration. Wheelbase varies with cab and bed length.

What is the ground clearance of a Sierra 3500HD?

10.4 inches on Pro, SLE, SLT, Denali and Denali Ultimate Crew Cab configurations, and 11.1 inches on AT4, whose off-road suspension raises it.

How many people can a Sierra 3500HD seat?

Five, on every Crew Cab configuration.

What is the maximum GVWR on a Sierra 3500HD?

Up to 14,000 pounds on the highest-rated DRW configuration, and as low as 10,950 pounds on the lightest Regular Cab build.

What wheel size does the Sierra 3500HD come with?

20-inch wheels across every trim, with painted alloy wheels standard on the base trims and unique finishes on AT4, Denali and Denali Ultimate.

Explore the Sierra 3500HD