GMC’s 2027 Sierra 2500 HD in AT4X trim with the diesel engine now carries a price of $100,595, destination charge included, making it the most expensive Sierra heavy-duty pickup on the price sheet. The figure covers one body style only: the Crew Cab with four-wheel drive, the configuration GM priced first. According to Autoblog, GM announced the pricing and the trucks are due at dealers in late 2026.
That total is the product of two lines on the price sheet. The AT4X starts at $89,195 with the standard gas V8, and the diesel adds $11,400 on top. Nothing else in the Sierra HD range reaches six figures through the options list alone, apart from one trim that bundles the engine in.
AT4X arithmetic on the 2027 price sheet
Autoblog senior editor Karl Furlong, writing on Oct. 7, set out GM’s new Crew Cab 4WD price list, and the ladder is tidy. The Pro starts at $57,495, the SLE at $61,895, the SLT at $69,195, the AT4 at $76,195 and the Denali at $78,895, each up $900 from 2026. The off-road AT4X lands at $89,195, also up $900. Every figure includes destination.
GM Authority’s version of the same table puts the destination freight charge at $2,795 and shows the AT4X diesel at $100,595, up $2,310 from the 2026 model. The two outlets agree on the total, which matters because GM’s own 2027 Sierra HD pages did not yet carry the new numbers when this was written. The current gmc.com Sierra HD page still lists the 2026 truck, with the AT4X starting at $85,500 before any diesel is added, so the $89,195 gas figure for 2027 comes from the trade reports of GM’s announcement rather than from the brand’s configurator.
The jump is easier to judge against what the same truck cost a year ago. A fully loaded 2026 AT4X AEV Edition came to $112,118 in GM Authority’s September 2025 build, but that required the $9,390 AEV package and a $9,990 diesel on a base AT4X priced at $86,295. The 2027 diesel option alone now costs $11,400, so the AT4X crosses $100,000 with no packages at all and leaves headroom for the AEV Edition and other add-ons above it.
Duramax output behind the $11,400 option
Autoblog describes the diesel as an 8.3-liter Duramax V8 rated at 555 horsepower and 1,230 lb-ft of torque, with GMC claiming both figures top Ford’s high-output Power Stroke. GM Authority’s report on the sister Silverado HD price list identifies the engine as the L6P. It replaces the 470-horsepower, 975 lb-ft 6.6-liter L5P and costs $1,410 more than the old diesel option did at $9,990.
One wrinkle: GM Authority’s Sierra table labels its columns with the outgoing L8T gas and L5P diesel engine codes, even though the $11,400 premium matches the new L6P’s price on the Silverado side. The $100,595 total is the same in either reading.
Towing climbs with the engine. Autoblog reports up to 38,000 pounds with the diesel, and the 2027 trucks also get 14.6-inch front brake rotors and a new Tow/Haul calibration. The AT4X itself adds improved DSSV dampers and a trim-specific Terrain Mode, which GMC pitches as the most capable off-road Sierra in the range. The standard gas engine is a 6.6-liter V8 making 412 horsepower and 472 lb-ft.
Denali Ultimate and the unpriced configurations
The only Sierra HD that comes close is the Denali Ultimate at $99,395, up $2,400, and it is diesel-only: the 8.3-liter engine is standard there, which is why it sits $1,200 below the AT4X diesel despite wood trim, massaging power front seats, Bose audio and illuminated power-assist steps.
Much of the range has not been priced. Regular and double cabs, rear-wheel-drive models and the 3500 HD variants were all missing from the announcement, and Furlong estimated a Regular Cab Pro at about $51,000 on the assumption of the same $900 increase. He also expects GMC to fully update the HD line roughly a year from now.
Autoblog lines the Sierra against Ford’s F-250 with destination included: an XL Crew Cab 4×4 at $55,935 and a Platinum Crew Cab 4×4 at $82,410. Furlong’s own verdict is that more than $100,000 “will sound excessive to the average sedan or SUV driver,” though he argues the price fits a luxury-focused truck.
GM Authority adds a wrinkle on the size of the increase: GMC raised 2026 HD prices by $300 earlier in the model year, so measured against pre-adjustment 2026 pricing the diesel trucks are $2,610 higher, not $2,310. The AT4X diesel at $100,595 sits at the top of that ladder, and its price will be tested once configurators open and the first 2027 trucks reach showrooms.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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