GMC Sierra 3500HD

Form and function come together in the new Sierra Heavy Duty


Bigger, stronger and smarter, the all-new 2020 GMC Sierra Heavy Duty combines greater trailering capability with technologies designed to provide customers with a world-class towing experience.

Form and function come together in the new Sierra Heavy Duty, with features that include:

  • An enhanced ProGrade Trailering system featuring class-leading available 15 camera views, including a segment-first transparent trailer view to virtually see through a trailer in tow
  • Available 15-inch-diagonal head-up display that offers useful trailering information, including vehicle speed, navigation information and an inclinometer display for the road grade
  • An available segment-first Rear Camera Mirror
  • MultiPro, the world’s first six-function tailgate, allows easier loading, unloading and bed access and is available on all trim levels.
  • A larger, commanding design that provides more room for cargo and occupants.
  • Best-in-class Crew Cab front headroom and legroom for the driver and other front-row occupants
  • An all-new, segment-first, Allison 10-speed automatic transmission mated to the legendary Duramax 6.6L V-8 turbo-diesel engine
  • For those looking to take refined capability off-road, GMC fortifies the new AT4 brand with an all-new Sierra AT4 Heavy Duty available for Crew Cab configurations as both a 2500 and 3500 single rear wheel offering

With more than half of Sierra HD customers choosing Denali, it continues to offer the ultimate expression of professional grade materials and refinement.

The all-new model delivers power, intelligence and segment advancements to meet the needs of heavy-duty customers with discerning taste.

In addition to Denali, the 2020 Sierra Heavy Duty lineup is offered in Sierra, SLE, SLT and new AT4 models. Denali and AT4 models are offered exclusively in 4WD.  









The redesigned cabin in the Sierra HD combines triple door seals, inlaid doors and other refinements throughout the truck to create the quietest heavy duty GMC pickup ever. Add premium materials, supportive seats and generous storage and you've set the new standard in heavy-duty truck interiors. Sierra HD also has heated and cooled Denali-embossed leather-trimmed front bucket seats, a heated leather-wrapped steering wheel, new soft-touch instrument panel with burnished aluminium trim and contrasting stitching.



The Sierra HD's all-new instrument panel puts controls where they're most visible - at your fingertips - and information at the sound of your voice thanks to a new available 20 cm diagonal colour touch radio with navigation system. Sierra HD provides the latest technologies to help you work smarter and more efficiently. From available driver alert safety technologies to Sierra HD's personalised driver display, you're surrounded by everything you need to perform your best.


An available centre console storage compartment is designed to double as a filing cabinet, so you'll have a place to keep hanging files, a laptop and other mobile devices.



In a GMC pickup first, Sierra introduces new projected-beam headlamps fully integrated into the grille surround. The lamps are further enhanced by available LED signature lighting. In addition to triple door seals and thicker windscreen glass, Sierra's sculptured styling helps reduce wind noise to create a quieter cabin.



GMC Sierra 3500HD was engineered to tow heavy loads in extreme conditions, thanks to a host of trailering technologies like Stabilitrak, Trailer Sway Control, the Diesel Exhaust Brake and Hill Start Assist. Combine these with the dual wheels and you have a towing champion.


  • Steering - power
  • Tow Haul Mode
  • Rear axle - 3.73 ratio
  • Optional Trailer wiring provisions
  • Rear multi-leaf, semi-elliptical with urethane jounce bumpers
  • Suspension - front independent with torsion bars, includes 51mm twin-shock absorbers and 33mm front stabiliser bar
  • Stabilitrak Stability Control System
  • Air cleaner - high capacity
  • Battery - heavy-duty maintenance-free run-down protection and retained accessory power
  • Integrated trailer brake controller
  • Frame - fully boxed with hydro-formed front section
  • Optional High idle switch
  • Optional Exhaust brakes - switch activated
  • Auxiliary external engine oil cooler
  • Alternator - 150 amps
  • Exhaust - aluminized stainless steel muffler and tailpipe
  • Auxiliary external transmission oil cooler
  • 18" wheels
  • Eaton heavy-duty automatic rear differential
  • Brakes - 4 wheel disc with 4-wheel antilock
  • Optional 20" wheels


  • Engine - Duramax 6.6 litre Turbo-Diesel V8 with direct injection
  • Transmission - Allison 1000 series 6-speed automatic includes tow-haul mode and electronic Powertrain Grade Braking
  • 4x4 - electronic shift rotary dial controls 2-speed and 2.69-to-1 low-range



The GMC Sierra 3500HD features an interior designed to bring you three key things: more comfort, less noise and a seamless connection to your digital world.

  • Air Conditioning – dual-zone climate control
  • Driver Information Centre - with 10.5 cm diagonal colour display
  • Steering wheel - leather wrapped with audio and cruise control
  • Steering wheel - heated
  • Steering column - tilt-wheel and telescope manual operation
  • Cruise control
  • Defroster - rear-window electric
  • Power equipment - power door locks and windows
  • Floor covering - colour-keyed carpeting with rubberised vinyl floor mats
  • Front and rear park assist - ultrasonic
  • Power adjustable pedals
  • Rear view camera system with dynamic grid lines
  • Remote start system
  • Remote keyless entry
  • Rearview mirror with inside rearview auto-dimming feature, included with outside heated power-adjustable vertical chrome-capped camper mirror
  • Sill plates - bright accent
  • Optional Sunroof - power sliding with express-open
  • Windows - power with driver express up-and-down and express down on all other windows
  • Power rear sliding window with rear defroster
  • Windshield wipers - interval control
  • 20.3 cm diagonal colour touch screen radio
  • Single slot CD/MP3
  • Bluetooth for phone
  • 6-speaker audio system, Bose premium audio system with six speaker (7 speaker including subwoofer when ordered with bucket seats)
  • Heated and cooled perforated leather-appointed front bucket seats - requires front bucket seats
  • Seats - rear folding 60/40 spilt 3-passenger bench, includes child seat top tether anchor



The impressive appearance of the GMC Sierra 3500HD is enough to tell you this full-size pickup is ready for whatever you throw at it. Plenty of tray space, easy-lift tailgate and an ingenius step-up are all part of the ready-for-work package.

  • Bumpers - rear, body colour with Cornerstep bumper
  • Bumpers - body colour
  • Side steps - chromed tubular with 15 cm rectangular design
  • Door handles - chrome
  • Moldings - bodyside, chrome
  • Grille - chrome with unique Denali accents
  • Headlight - halogen projector-beam
  • Lights - under-rail LED lighting, cargo box
  • Exterior towing mirrors - heated
  • Wipers - front intermittent
  • Wheelhouse liners - rear, single wheel
  • Tailgate - locking with EZ-lift and lower tailgate feature
  • Optional Cargo box - movable tie-downs, high-mounted (4)
  • Recovery hooks - front frame-mounted (black)
  • Optional Cargo box - box rail caps
  • Tyre carrier - outside spare, winch-style includes lock
  • Optional Spray-in bedliner
  • Optional Roll-up tonneau cover
  • Glass - solar-ray deep tinted



GMC Sierra HD is a step up in safety with standard daytime running lights, tyre pressure monitoring system and rear vision camera as just the start.


  • Optional Lane departure warning and forward collision alert - included and only available with Driver Alert Package
  • Optional Safety Alert Driver Seat - included and only available with Driver Alert Package
  • Airbags - front-seat-mounted side-impact driver and right front-passenger air bags for thorax and pelvis protection
  • Airbags - single-stage frontal for driver and front passenger
  • Exhaust brakes
  • Tyre pressure monitoring system (excludes spare)
  • ABS brakes
  • Optional Airbags - front and rear head curtain side-impact air bags for all outboard seating positions
  • Tailgate - locking
  • Theft Deterrent System - includes and only available with Driver Alert package

Please note that these colour and seating options are presented for information only. Performax cannot guarantee vehicles of particular colour and seating will be in stock at any given time. Please call our professional sales time on 1800 737 367 to enquire about our available colours.

Exterior colour options

GMC Denali colours exterior

Interior colour options

GMC Denali colours interior


Performax International offers an industry exclusive three year/100,000km factory backed new car warranty with 24 hour Road Side Assist. This is backed 100% by our factory; it is not an after-market new car warranty or mechanical warranty as favoured by most companies.

A Performax Warranty is all about looking after the customer, not looking for reasons to decline a claim. The customer doesn’t call an office in a major city and talk to an operator that knows nothing about the vehicle, and only thinks of them as a number; they call their Performax Dealer or Head Office and deal direct with an employee that usually knows what they are talking about.


Performax International operates the only original equipment manufacturer (OEM) style dealership network in Australia, with dealers throughout the country stocking and servicing our vehicles. Customers often question the ability to get help when travelling in remote areas; it’s no different to any other modern vehicle.

Basic repairs can be done anywhere by any competent mechanic, and Performax is happy to offer them assistance over the phone. Most common parts are carried in Australia and can be despatched same day, just like a Toyota. And just like a Toyota if it’s not a common replacement part it gets flown in from overseas usually within seven to 10 days.


Performax International carries an extensive range or spare parts, genuine and aftermarket accessories. Customers have the ability to customise their vehicles to suit the application, whether it be outback touring, heavy duty towing, or a show pony we can accommodate.


Brought your own vehicle in to Australia for us to convert it? Your conversion has its own 12 month / 20,000km warranty.

For more information about the Performax International warranty, please call 1800 737 367.

While all efforts are made to ensure Vehicle specifications and features are correct at the time of publication, it is the consumers responsibility to verify these before making a purchasing decision. Performax International cannot be held responsible for changes in specifications or changes made to meet ADR’s.