| Monday | 9:00am - 8:00pm |
| Tuesday | 9:00am - 8:00pm |
| Wednesday | 9:00am - 8:00pm |
| Thursday | 9:00am - 8:00pm |
| Friday | 9:00am - 5:30pm |
| Saturday | 9:00am - 5:30pm |
| Sunday | Closed |
| Monday | 7:30am - 5:30pm |
| Tuesday | 7:30am - 5:30pm |
| Wednesday | 7:30am - 5:30pm |
| Thursday | 7:30am - 5:30pm |
| Friday | 7:30am - 5:30pm |
| Saturday | 7:30am - 1:00pm |
| Sunday | Closed |
| Monday | 8:00am - 5:30pm |
| Tuesday | 8:00am - 5:30pm |
| Wednesday | 8:00am - 5:30pm |
| Thursday | 8:00am - 5:30pm |
| Friday | 8:00am - 5:30pm |
| Saturday | 8:00am - 1:00pm |
| Sunday | Closed |
| Monday | 8:00am - 5:00pm |
| Tuesday | 8:00am - 5:00pm |
| Wednesday | 8:00am - 5:00pm |
| Thursday | 8:00am - 5:00pm |
| Friday | 8:00am - 5:00pm |
| Saturday | Closed |
| Sunday | Closed |
$101,668.00 x 84 months @ 2.49% APR with $0.00 down payment (4.98% effective rate, cost of borrowing $9,166.18). Plus HST and license.
$101,668.00 x 84 months @ 2.49% APR with $0.00 down payment (4.98% effective rate, cost of borrowing $9,166.18). Plus HST and license.
$101,668.00 x 48 months @ 3.9% APR with $0.00 down payment (24,000 km/yr lease allowance, 6.93% effective rate, cost of borrowing $11,718.13). Plus HST and licence.
$101,668.00 x 48 months @ 3.9% APR with $0.00 down payment (24,000 km/yr lease allowance, 6.93% effective rate, cost of borrowing $11,718.13). Plus HST and licence.
This one doesn’t sneak up on you… it announces itself with authority. The 2026 GMC Sierra AT4 Crew Cab in Onyx Black pairs raw V8 power with off-road capability and premium craftsmanship. It’s a truck built for drivers who want muscle underfoot and refinement at their fingertips.
This is the heartbeat of the AT4:
• 6.2L EcoTec3 V8 • 420 horsepower / 460 lb-ft of torque • Dynamic Fuel Management for efficiency
Press the throttle and it responds instantly… no waiting, no hesitation, just power on demand.
• 10-speed automatic transmission • Tow/haul mode with grade braking • Steering column paddle shifters
It delivers power like a seasoned heavyweight… controlled, confident, and always composed.
Built to explore beyond the pavement:
• All-terrain tires with off-road suspension tuning • Off-Road High Clearance Steps • Factory skid protection and rugged AT4 stance
Mud, gravel, snow… it treats them all like scenery.
• 20" machined aluminum wheels with Carbon Grey accents • Onyx Black exterior for a stealth, aggressive look • Signature AT4 styling throughout
It looks like it belongs anywhere… because it does.
• Perforated leather seating with Kalahari accents • Heated comfort and premium finishes • Power sunroof to open up every drive
It’s the kind of interior that makes you forget you’re in a truck… until you use it like one.
• 13.4" GMC Infotainment System with Google Built-In • Wireless Apple CarPlay & Android Auto • 15" Multicolour Head-Up Display • Rear Camera Mirror with full display
Everything is intuitive, responsive, and right where it should be.
• Bed View Camera for cargo and hitch alignment • Rear Camera Mirror for unobstructed rear visibility • Trailer Camera Provisions
Hooking up and backing in becomes almost effortless.
This AT4 doesn’t just move… it sounds the part:
• Active dual exhaust with sport mode • Performance air intake system • Heavy-duty cooling systems
It breathes deeper, runs cooler, and sounds sharper.
Loaded with meaningful upgrades:
• Universal Home Remote • Power rear sliding window • Advanced display and camera technologies • Enhanced off-road usability
• Hard folding truck bed cover • Black sport steps (dealer-installed) • 170-amp alternator
Built to handle your weekday workload and weekend escapes.
• 3 Years of SiriusXM
At Boyer Chevrolet Buick GMC Ajax, located at 425 Bayly Street West, you’re backed by a team that understands trucks inside and out, supported by a 4.7-star rating with over 1,500 reviews.
You get:
• Truck specialists who understand performance and capability • Competitive financing options • A trusted dealership serving Ajax, Whitby, Oshawa & Durham Region • Full support from factory-trained technicians
If you’re cross-shopping trucks like the Ford F-150 Tremor, Ram 1500 Rebel, or even the Chevrolet Silverado Trail Boss, the Sierra AT4 6.2L V8 stands apart with its blend of raw performance, off-road capability, and premium refinement.
📞 Call 905-427-2500 📍 Visit Boyer Chevrolet Buick GMC Ajax 📅 Book your test drive today
Power you can hear. Capability you can feel.