The 2027 GMC Sierra HD diesel price is going up, but there are two different numbers buyers need to understand. The new 8.3L Duramax option costs $11,400, up $1,410 from GMC’s listed 2026 diesel charge. Add a $900 increase in the truck’s gas-engine MSRP, and most diesel-equipped 2500HD Crew Cab 4WD trims rise $2,310 over 2026.
The chart covers 2500HD Crew Cab 4WD trucks specifically. It puts the gas-powered Pro at $57,495, the diesel Pro at $68,895 and the diesel-only Denali Ultimate at $99,395. Those are the supplied MSRPs, not a blanket starting price for every Sierra HD configuration.
The 8.3L Duramax option costs $1,410 more
GMC’s comparison lists the outgoing diesel option at $9,990 and the 2027 replacement at $11,400. That is the price of selecting the diesel instead of the gas engine on trims offering both. It is separate from the year-over-year increase in the complete truck. The 8.3L replaces the 6.6L diesel as the available Duramax engine, rather than arriving as an additional specialty performance option.
The new diesel is rated at 555 horsepower and 1,230 lb-ft of torque. We have already examined its hardware in our 8.3L Duramax engineer walk-around. GMC’s email also lists the enhanced gas V8 at 412 horsepower and 472 lb-ft. Buyers therefore have changes to weigh on both sides of the gas-versus-diesel decision.
2027 GMC Sierra HD diesel price by trim
Here are GMC’s supplied 2027 MSRPs for the 2500HD Crew Cab 4WD lineup. The $11,400 diesel option applies to the six trims that offer a choice of engines. Denali Ultimate is diesel-only.
| 2500HD trim | 2027 gas | 2027 diesel |
|---|---|---|
| Pro | $57,495 | $68,895 |
| SLE | $61,895 | $73,295 |
| SLT | $69,195 | $80,595 |
| AT4 | $76,195 | $87,595 |
| Denali | $78,895 | $90,295 |
| AT4X | $89,195 | $100,595 |
| Denali Ultimate | Not offered | $99,395 |
The diesel AT4X crosses $100,000 in the supplied table, at $100,595. Denali Ultimate comes in slightly below that at $99,395. These trims serve different priorities, so the price order alone does not tell you which truck has the equipment that matters most to you.
Most diesel trucks rise $2,310; Denali Ultimate rises $2,400
The Pro, SLE, SLT, AT4, Denali and AT4X each gain $900 in gas-engine MSRP. Each corresponding diesel truck rises $2,310 because its new price combines that $900 change with the $1,410 diesel-option increase. Denali Ultimate is the exception: GMC lists no gas version, and its diesel MSRP rises from $96,995 to $99,395, a $2,400 increase.
| Diesel trim | 2026 MSRP | 2027 MSRP |
|---|---|---|
| Pro | $66,585 | $68,895 |
| SLE | $70,985 | $73,295 |
| SLT | $78,285 | $80,595 |
| AT4 | $85,285 | $87,595 |
| Denali | $87,985 | $90,295 |
| AT4X | $98,285 | $100,595 |
| Denali Ultimate | $96,995 | $99,395 |
That differs from the figures in our 2027 Chevrolet Silverado HD pricing story. Chevrolet quoted a $9,900 outgoing diesel option; GMC’s table says $9,990. I am keeping each brand’s supplied figures separate. The cab and drivetrain basis also matters, so the two stories’ starting prices should not be treated as a matched Chevrolet-versus-GMC comparison.
What changes, and what still needs confirmation
Beyond the engines, GMC says the updates include electric power steering, eBoost braking and larger front brake rotors. AT4X gains larger DSSV dampers and a new Terrain Mode. These are announced hardware changes, not my driving impressions. GM has described the wider HD program in its official powertrain announcement.
The pricing material does not say whether destination is included or identify the bed configuration behind every figure. I would confirm those details, along with options and dealer charges, before treating one of these MSRPs as a complete purchase budget. I am not adding Chevrolet’s destination fee to GMC’s numbers.
For now, the useful takeaway is straightforward: the diesel upgrade itself is $11,400. The typical $2,310 increase is what happens when you compare the complete 2027 diesel truck with its 2026 counterpart in GMC’s specified configuration. Those are two different comparisons, and both matter when deciding whether to order the new truck.
