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2025 GMC Sierra HD OVERVIEW

2025 GMC Sierra HD in Alton

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12.3" diagonal color Driver Information Center
Engine, 6.6L V8 with Direct Injection and Variable Valve Timing, gasoline, (401 hp [299 kW] @ 5200 rpm, 464 lb-ft of torque [629 N-m] @ 4000 rpm) (STD)
18" machined aluminum wheels with Dark Grey metallic accents
Front Pedestrian Braking (Included and only available with (PDI) Sierra HD Pro Safety.)

2025 GMC Sierra HD MODELS

Sierra HD PRO
Sierra HD SLE
Sierra HD SLT
Sierra HD AT4
Sierra HD DENALI
Sierra HD AT4X
Sierra HD DENALI ULTIMATE

GMC Sierra HD Dealer in Alton

2025 GMC Sierra HD PERFORMANCE

DURAMAX 6.6L TURBO-DIESEL V8 ENGINE

Sierra Heavy Duty’s available Duramax 6.6L Turbo-Diesel V8 engine features an efficient turbocharger and Allison 10-speed automatic transmission.

ADVANCED TRAILERING TECH

The 2025 Sierra Heavy Duty offers more trailering-assistance technologies than any competitor in its class, so you can trailer with confidence.

2025 GMC Sierra HD APPEARANCE

BOLD FRONT END

Stand out everywhere you go with GMC Sierra HD Denali’s iconic chrome grille, front bumper and fascia.

SIX-FUNCTION MULTIPRO TAILGATE

The powerfully innovative available MultiPro Tailgate combines six convenient functions to help make light work of almost any job in your work truck.

LED PROJECTOR HEADLAMPS AND SIGNATURE LIGHTING

LED projector headlamps with striking animated sequences help enhance Sierra Heavy Duty’s impressive exterior design.

2025 GMC Sierra HD COMFORT

LUXURIOUS MATERIALS

Sierra HD Denali Ultimate’s Alpine Umber interior features full-grain leather seating, plaited contrast stitching, and embossed and laser-etched topographical map patterns of Mt. Denali’s summit.

16-WAY POWER FRONT SEATS WITH MASSAGING FEATURE

Experience serious comfort in Sierra Heavy Duty’s available best-in-class* 16-way power front seats with massaging feature.

SPACIOUS CABIN

The Sierra Heavy Duty truck features best-in-class Crew Cab front head and leg room.*

15" DIAGONAL MULTICOLOR HEAD-UP DISPLAY

The available 15" diagonal Head-Up Display helps keep important information like speed and alerts in clear view.

2025 GMC Sierra HD SAFETY & WARRANTY

PRO GRADE PROTECTION

Standard on every new GMC - GMC Pro Grade Protection has you truly protected with features and services including:

3-year / 36,000-mile Bumper-to-Bumper Limited Warranty
5-year / 60,000-mile Powertrain Limited Warranty
5-year / 60,000-mile Roadside Assistance & Courtesy Transportation
3-year / 36,000-mile Corrosion Protection
6-year / 100,000-mile Rust-Through Protection
First maintenance visit

FORWARD COLLISION ALERT

Forward Collision Alert can warn you if it detects a potential front-end collision with a vehicle you’re following so you can quickly take action. It can also provide a tailgating alert if you’re following a vehicle much too closely.

FRONT AND REAR PARK ASSIST

Front and Rear Park Assist* can provide distance alerts to nearby detected objects in front of or behind your vehicle to help you park and avoid collisions at low speeds.

LANE CHANGE ALERT WITH SIDE BLIND ZONE ALERT*

Lane Change Alert with Side Blind Zone Alert can provide side-mirror visual alerts when a detected moving vehicle is quickly approaching or is in your side blind zone. It can help you avoid lane change collisions.

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2025 GMC Sierra HD OVERVIEW

2025 GMC Sierra HD in Alton

2025 GMC Sierra HD MODELS

Sierra HD PRO

Sierra HD SLE

Sierra HD SLT

Sierra HD AT4

Sierra HD DENALI

Sierra HD AT4X

Sierra HD DENALI ULTIMATE

GMC Sierra HD Dealer in Alton

2025 GMC Sierra HD PERFORMANCE

DURAMAX 6.6L TURBO-DIESEL V8 ENGINE

ADVANCED TRAILERING TECH

2025 GMC Sierra HD APPEARANCE

BOLD FRONT END

SIX-FUNCTION MULTIPRO TAILGATE

LED PROJECTOR HEADLAMPS AND SIGNATURE LIGHTING

2025 GMC Sierra HD COMFORT

LUXURIOUS MATERIALS

16-WAY POWER FRONT SEATS WITH MASSAGING FEATURE

SPACIOUS CABIN

15" DIAGONAL MULTICOLOR HEAD-UP DISPLAY

2025 GMC Sierra HD SAFETY & WARRANTY

PRO GRADE PROTECTION

FORWARD COLLISION ALERT

FRONT AND REAR PARK ASSIST

LANE CHANGE ALERT WITH SIDE BLIND ZONE ALERT*

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Disclaimers