Rivard Buick GMC · Tampa, FL
2027 GMC Sierra HD: Release Date, Engines, Towing and What's New
GM revealed the 2027 Sierra 2500HD and 3500HD on September 24, 2026, and the headline is under the hood: an all-new Duramax 8.3L Turbo-Diesel V8 rated at 555 hp and 1,230 lb-ft. The gas 6.6L V8 is enhanced, steering and brakes are new, and GM expects the trucks at U.S. dealers beginning late 2026. Pricing has not been announced. This page tracks what GM has published, and only that.
The Direct Answer
When Does the 2027 Sierra HD Arrive, and What Changed?
Last updated September 29, 2026 by Rivard Buick GMC
Late 2026, per GM. GM's September 24 announcement says the 2027 Sierra 2500HD and 3500HD are expected to reach U.S. dealers beginning late 2026, and gmc.com lists the truck as available late 2026. GM does not give an exact production or order date. It also does not call this a redesign: GM's word is updates, and the list is long. There is a new Duramax 8.3L Turbo-Diesel V8 at 555 hp and 1,230 lb-ft, an enhanced 6.6L gas V8 at 412 hp and 472 lb-ft, electric power steering, electronic brake-boost and new trailering tech.
For a Tampa Bay buyer the practical read is simple. If you tow heavy, the diesel is the news, and GM expects the trucks within months. If you need a truck today, current Sierra HD inventory is on the lot and priced under our One Price Promise. Either way, the numbers below come from GM's release and gmc.com, so you can hold us to them.
Signal vs. Noise
2027 Sierra HD: Announced, Expected, and Not Yet Published
| Topic | Status | Details |
|---|---|---|
| Reveal | Announced | GM published the 2027 Sierra HD announcement on September 24, 2026. gmc.com carries a 2027 Sierra HD page under Future Vehicles. |
| Arrival at Dealers | Expected | GM expects the trucks at U.S. dealers beginning late 2026. No exact production or order date has been published. |
| Diesel Engine | Announced | New Duramax 8.3L Turbo-Diesel V8, 555 hp and 1,230 lb-ft, with the Allison 10-speed 10L1000 automatic. Built at GM's DMAX plant in Brookville, Ohio. GM says it is best-in-class for diesel horsepower and torque, based on the latest available competitive information and excluding other GM vehicles (SAE J1349). |
| Gas Engine | Announced | Enhanced 6.6L V8, standard, 412 hp and 472 lb-ft, also with the Allison 10-speed. Built at GM's Tonawanda, New York engine plant. GM says its torque is best-in-class among standard 2027 model-year HD gas engines. |
| Steering and Brakes | Announced | Segment-first rack-and-pinion electric power steering replaces hydraulic assist, and a segment-first electronic brake-boost system (eBoost on gmc.com) joins 14.6-inch front rotors. |
| Towing | Announced | Up to 23,100 lb on the 2500HD and 38,000 lb on the 3500HD, maximum available, properly equipped, select configurations. GM also cites up to 20,000 lb conventional, 38,000 lb gooseneck and 46,500 lb GCWR. |
| Trims | Announced | Pro, SLE, SLT, AT4, AT4X, Denali and Denali Ultimate are listed on gmc.com. |
| Pricing | Not Announced | GM says MSRP will be announced in future updates. We will post it here the day it is public. |
| Fuel Economy, Payload, Tow Tables | Not Published | Fuel economy, payload and per-engine, per-cab towing tables were not in the GM release or on gmc.com when we read them on September 29, 2026. |
Sources: GM's September 24, 2026 news release on the Duramax 8.3L and Heavy-Duty lineup, and the 2027 Sierra HD page on gmc.com. Rivard Buick GMC revises this page when either changes.
The Trucks
2027 Sierra 2500HD vs. 3500HD: Two Ratings, One Update
The updates on this page are for the 2027 Sierra HD lineup, 2500HD and 3500HD. What separates the two trucks is the ceiling. GM's maximum available towing is 23,100 lb on the 2500HD and 38,000 lb on the 3500HD, and GM says every diesel dually can tow up to an available 30,000 lb or more. Those are maximums for properly equipped, select configurations, so the exact number depends on the truck you build.
Sierra 2500HD
Volume Heavy Duty- Max TowingUp to 23,100 lb, maximum available
- EnginesSierra HD engine lineup below
- TransmissionAllison 10-speed 10L1000
- Best ForFifth-wheel campers, big boats, equipment trailers you also want to daily-drive
- ExploreSierra 2500 model page
Sierra 3500HD
Maximum Capability- Max TowingUp to 38,000 lb, maximum available
- EnginesSierra HD engine lineup below
- Diesel DuallyGM says up to an available 30,000 lb or more on every diesel dually
- Best ForCommercial hauling, big gooseneck and horse trailers, heavy equipment
- ExploreSierra 3500 model page
Under the Hood
The 2027 Sierra HD Engines: Duramax 8.3L and Enhanced 6.6L Gas
The Duramax 8.3L Turbo-Diesel V8 is GM's first clean-sheet heavy-duty V8, designed, developed and built in-house at the DMAX facility in Brookville, Ohio. It has a compacted graphite iron block, a forged crankshaft and connecting rods, steel pistons, dual-stage air-to-water charge cooling and a variable-geometry turbocharger, plus upgraded exhaust braking and a new aftertreatment layout. gmc.com lists it as part of the Denali Ultimate.
The standard gas engine is the enhanced 6.6L V8 with a new Turbo-Jet intake manifold, a revised lubrication system, an engine-mounted oil cooler and a digital oil-level display. Both engines pair with the Allison 10-speed 10L1000.
| Engine | Output | Availability and Build |
|---|---|---|
| Duramax 8.3L Turbo-Diesel V8 | 555 hp 1,230 lb-ft |
Available. Built in Brookville, Ohio. |
| Enhanced 6.6L V8 (gas) | 412 hp 472 lb-ft |
Standard. Built in Tonawanda, New York. |
Control and Trailering
Steering, Brakes and Trailer Tech: What GM Changed Around the Engine
| System | What GM Says |
|---|---|
| Steering | Segment-first rack-and-pinion electric power steering replaces hydraulic assist. GM cites about 30% more power than the current HD hydraulic gear, and assist no longer depends on engine speed. |
| Brakes | Segment-first electronic brake-boost (eBoost on gmc.com), 14.6-inch front rotors, four-piston fixed front calipers and upgraded rear hardware. It supports Adaptive Cruise Control and Automatic Emergency Braking. |
| Drive Modes | Normal, Tow/Haul and Off-Road. New Terrain Mode on the AT4X gives one-pedal off-road driving in 4HI and 4LO, a first for GM heavy-duty trucks. |
| Trailering Tech | Up to 14 available camera views, including Transparent Trailer View, Bed View and Surround Vision. Also available: an in-vehicle trailering app, Trailer Side Blind Zone Alert, trailer tire pressure and temperature monitoring, and the ProGrade Trailering System. Adaptive Cruise Control works with a trailer attached. |
| Screens | Available 13.4-inch Premium GMC Infotainment System, available 12.3-inch Driver Information Center and available 15-inch multicolor Head-Up Display. |
Trim by Trim
2027 Sierra HD Trims: Pro to Denali Ultimate
| Trim | What gmc.com Lists |
|---|---|
| Pro | 6.6L V8 gas with the Allison 10-speed, Adaptive Cruise Control with trailering capability, Trailering Package with trailering mirrors and a trailer brake controller. |
| SLE | 13.4-inch Premium GMC Infotainment and 12.3-inch digital Driver Information Center, Traction Select System with Tow/Haul mode, 18-inch machined aluminum wheels. |
| SLT | Available 10-way power heated and ventilated front bucket seats in perforated leather, heated steering wheel, ProGrade Trailering System with the In-Vehicle Trailering App. |
| AT4 | Jet Black interior with Kalahari accents, heated and ventilated perforated leather front seats, 20-inch Gloss Black wheels, available BFGoodrich All-Terrain tires, Off-Road Suspension Package with twin-tube shocks and skid plates. |
| AT4X | Factory 1.5-inch suspension lift, Multimatic DSSV dampers, rear electronic-locking differential, larger steel transfer case skid plate, front aluminum skid plate, 35-inch Goodyear Territory MT tires, 16-way heated and ventilated power front seats with massage, and Terrain Mode. |
| Denali | 20-inch Ultra-Bright machined aluminum wheels with chrome inserts, authentic wood and patterned aluminum trim, Forge perforated leather, 12-way heated and ventilated power front seats. |
| Denali Ultimate | Duramax 8.3L Turbo-Diesel V8 with the Allison 10-speed, Vader Chrome grille, 20-inch Ultra-Bright wheels with Gloss Black inserts, Alpine Umber interior with full-grain leather and Paldao wood, 16-way power front seats with massage. |
Decision Framework
Buy a Sierra HD Now, or Hold for the 2027?
The 2027 trucks are expected late this year, and GM has not priced them. That leaves three sensible paths, and which one fits depends on when your current truck stops working for you.
Need It Now
Buy a Sierra HD From Inventory
Current Sierra 2500HD and 3500HD trucks are on the lot on Adamo Drive with known pricing under our One Price Promise. Nothing about the 2027 announcement changes what a truck in stock can do today.
Shop HD InventoryWant the Half-Ton Instead
Look at the 2027 Sierra 1500
If your trailer fits within a half-ton, the redesigned 2027 Sierra 1500 has its own page with engines, interior and trims laid out in full.
2027 Sierra 1500 OverviewWant the 8.3L Diesel
Get on the Update List
If the new Duramax is the reason you are shopping, join our update list below. We will tell you when GM publishes pricing and when ordering is set, and you can ask us about a Denali Ultimate build.
Join the Update List
Still Open
What GM Has Not Said About the 2027 Sierra HD Yet
Four things were not public when we read the sources: MSRP, an exact production or order date, fuel economy, and payload. GM has not released per-engine or per-cab towing tables either, only the maximums above. We read GM's release and gmc.com on September 29, 2026, and none of these was in them. When GM publishes them, this page is where we will put them first. In the meantime, our 2027 GMC Sierra overview and engine guide cover the half-ton.
Stay Ahead of the Announcement
Get Sierra HD Updates First
Join our update list and you will hear from us when GM releases 2027 Sierra HD pricing and again when ordering opens. No obligation. Tell us in the comments which engine and which trim you are watching, and whether you run a 2500 or 3500 today, so we can follow your build from the start.
Need a truck before late 2026? Current Sierra 2500HD and 3500HD trucks are in stock on Adamo Drive with transparent One Price Promise pricing.
FAQ
2027 GMC Sierra HD: Frequently Asked Questions
When will the 2027 GMC Sierra HD be available?
GM expects the 2027 Sierra 2500HD and 3500HD at U.S. dealers beginning late 2026, and gmc.com says available late 2026. GM has not published an exact production or order date.
What engines does the 2027 Sierra HD have?
Two. The all-new Duramax 8.3L Turbo-Diesel V8 makes 555 hp and 1,230 lb-ft, and the enhanced 6.6L V8 gas engine, standard, makes 412 hp and 472 lb-ft. Both use the Allison 10-speed 10L1000 automatic.
How much can the 2027 Sierra 2500HD and 3500HD tow?
GM's maximum available towing is up to 23,100 lb on the 2500HD and up to 38,000 lb on the 3500HD, for properly equipped trucks in select configurations. GM also says every diesel dually can tow up to an available 30,000 lb or more. Per-engine and per-cab tables have not been published.
What is new on the 2027 Sierra HD?
The Duramax 8.3L Turbo-Diesel V8, an enhanced 6.6L gas V8, segment-first electric power steering, segment-first electronic brake-boost with larger front brakes, Terrain Mode on the AT4X, and up to 14 available camera views for trailering.
Is the 2027 Sierra HD redesigned?
GM describes the 2027 changes as updates, and neither GM's release nor gmc.com uses the word redesign. What GM did announce is a new diesel engine, an enhanced gas engine, new steering and brakes, and new trailering technology.
How much will the 2027 Sierra HD cost?
GM has not announced pricing. It says MSRP will be announced in future updates. We will post the number on this page when it is public.
Is the Duramax 8.3L standard on the Denali Ultimate?
gmc.com lists the Duramax 8.3L Turbo-Diesel V8 with the Allison 10-speed as part of the 2027 Denali Ultimate. We have not seen it listed as standard on any other trim, so ask us before you assume it on one.
Should I wait for the 2027 Sierra HD?
If you need a truck this season, buy from inventory: the trucks on our lot are real and priced, and 2027 pricing does not exist yet. If the 8.3L diesel or the new steering and brakes are what you want, join our update list and we will contact you as GM releases pricing and ordering details.
Does Rivard Buick GMC have Sierra HD trucks in stock?
Yes. We stock Sierra 2500HD and 3500HD trucks across the trim range at our Adamo Drive showroom in Tampa, serving Brandon, Riverview, Plant City, and the greater Tampa Bay area. Browse current Sierra HD inventory or call 813-280-0050.
Explore
More Sierra From Rivard Buick GMC
Shop Sierra HD Inventory
Sierra 2500 Model Page
Sierra 3500 Model Page
2027 Sierra 1500 Overview
2027 Sierra Engine Guide
2027 Sierra Interior & Tech
Reserve the 2027 Sierra
Business Elite Commercial
Rivard Buick GMC · 9740 Adamo Dr, Tampa, FL 33619 · Sales: 813-280-0050 · Serving Tampa, Brandon, Riverview, Seffner, Temple Terrace, Plant City, and Apollo Beach. Hours & Directions
All offers on all vehicles are subject to change at the discretion of Rivard Buick GMC. Rebates and incentives may change at any time, without notice. Always check with us to confirm all information shown and get up-to-date pricing, rebate information, and availability. You may qualify for additional offers and savings. We are not obligated to uphold typographical and system errors on our website. EPA Estimates Only. Tax and government fees are extra. Rivard Buick GMC will NOT sell or lease New Vehicles in the states of Alaska, Montana, New Hampshire, or Oregon unless primary residence is located in mentioned state. New Vehicles are for sale or lease to the Ultimate Consumer Only. Rivard Buick GMC will NOT sell or lease a New Vehicle to any person whose name, address, or business appears on the General Motors Suspected Exporter Manifest. Not available with special finance, lease and some other offers. Not available with special finance or lease offers.
The Manufacturer's Suggested Retail Price excludes tax, title, license, dealer fees and optional equipment. Dealer sets final price.