2027 GMC Sierra AT4 vs AT4X: Which Off-Road Trim Is Right for You?
The 2027 GMC Sierra 1500 AT4 and AT4X are both factory-lifted, off-road-ready pickups, but they are built for different drivers. The AT4 pairs a standard 5.7L V8 with a 2-inch factory lift and all-terrain tires for daily driving and light-to-moderate trail use. The AT4X adds mud-terrain tires, Multimatic dampers, front and rear electronic locking differentials, the Duramax 3.0L Turbo-Diesel as standard, and a Baja drive mode.
This guide compares the two trims side by side using GMC's published 2027 specifications, so you can decide how much off-road hardware you need before you visit Lynch GMC of Burlington in Burlington, WI.
In short:
- Choose the AT4 for the lower entry point, a standard V8, and capable all-around trail use.
- Choose the AT4X for GMC's top off-road Sierra, with two electronic lockers, a standard diesel, and Baja drive mode.
Model-year note: 2027 Sierra 1500 specifications and availability are preliminary and subject to change. Figures come from GMC's September 22, 2026 announcement and GMC.com, which say the first trucks are expected at dealerships before the end of 2026.
AT4 vs AT4X at a Glance
| Feature | Sierra AT4 | Sierra AT4X | Edge |
|---|---|---|---|
| Starting MSRP* (4WD Crew Cab) | $73,495 MSRP* | $85,495 MSRP* | AT4 (lower entry) |
| Standard engine | 5.7L V8 | 3.0L Duramax Turbo-Diesel | Depends on use |
| Factory lift | 2-inch | 2-inch | Tie |
| Shocks and dampers | Monotube shocks | Multimatic DSSV dampers with Jounce Control Dampers | AT4X |
| Tires | 34-inch all-terrain | 35-inch Goodyear Wrangler Territory MT | AT4X |
| Locking differentials | Auto-locking rear differential | Front and rear electronic locking differentials | AT4X |
| Baja drive mode | Not offered (AT4X-exclusive) | Standard | AT4X |
| Fuel tank (approx.) | 34-gallon available | 34-gallon standard | AT4X |
| Underbody cameras | Available | Standard | AT4X |
| Front passenger screen | 11.5-inch available | 11.5-inch standard | AT4X |
| Bose Premium Audio | 8-speaker | 16-speaker with head-restraint speakers | AT4X |
*Manufacturer's Suggested Retail Price (MSRP) for new vehicles includes manufacturer and distributor options and delivery, process and handling fees, which may be subject to change at any time. MSRP excludes taxes, title, license and dealer installed options, accessories, fees and charges. MSRP is not the dealer advertised price. Dealer price will vary. The dealer sets the final price.
Sources: GMC newsroom, Sept. 22, 2026, GMC.com 2027 Sierra 1500
Is the AT4X Price Premium Worth It?
The AT4X adds specific hardware and equipment:
- Electronic locking differentials at both axles
- Larger mud-terrain tires and Multimatic dampers
- The Duramax diesel and approximately 34-gallon fuel tank as standard
- Standard underbody cameras, passenger screen, and 16-speaker audio
- Baja drive mode
Whether that is worth the $12,000 MSRP* gap depends on how often you leave the road. Drivers who stay mostly on pavement and maintained trails may not use much of it. Drivers who regularly leave the road will.
*Manufacturer's Suggested Retail Price (MSRP) for new vehicles includes manufacturer and distributor options and delivery, process and handling fees, which may be subject to change at any time. MSRP excludes taxes, title, license and dealer installed options, accessories, fees and charges. MSRP is not the dealer advertised price. Dealer price will vary. The dealer sets the final price.
AT4 and AT4X Engines and EPA-Estimated Fuel Economy
Every 2027 Sierra 1500 engine pairs with a 10-speed automatic transmission. Each trim offers two engines:
| Trim | Engine | Availability | Horsepower | Torque | EPA-Estimated MPG, 4WD (city / hwy / combined) |
|---|---|---|---|---|---|
| AT4 | 5.7L V8 | Standard | 402 hp | 428 lb-ft | 15 / 18 / 16 |
| AT4 | 3.0L Duramax Turbo-Diesel | Optional | 305 hp | 495 lb-ft | 20 / 23 / 21 |
| AT4X | 3.0L Duramax Turbo-Diesel | Standard | 305 hp | 495 lb-ft | 20 / 22 / 21 |
| AT4X | 6.6L V8 | Optional | 481 hp | 501 lb-ft | 13 / 15 / 14 |
EPA-estimated fuel economy figures are for comparison purposes only. Your actual mileage will vary depending on driving conditions, how you drive and maintain your vehicle, battery age/condition, and other factors.
Sources: EPA fueleconomy.gov, 2027 GMC, GM Authority, Nov. 2026, GMC newsroom, Sept. 22, 2026
The 6.6L V8 leads in horsepower and peak torque, and the 5.7L V8 sits lower on both.
AT4 and AT4X Towing and Payload
GMC publishes towing and payload ratings by engine rather than by trim. GMC's highest ratings for the 5.7L V8 and the Duramax also depend on the Max Trailering Package, which GMC lists only for the Elevation trim. Those two engine maximums are ceilings, not AT4 or AT4X ratings. These are the Crew Cab 4WD figures:
| Engine | Offered on | Engine max towing | Engine max payload | Needs Max Trailering Package? |
|---|---|---|---|---|
| 5.7L V8 | AT4 (standard) | 13,300 lbs | 1,920 lbs | Yes (Elevation only) |
| 3.0L Duramax Turbo-Diesel | AT4 (optional), AT4X (standard) | 12,100 lbs | 1,790 lbs | Yes (Elevation only) |
| 6.6L V8 | AT4X (optional) | 9,400 lbs | 1,450 lbs | No (not offered with the 6.6L) |
Maximum towing and payload capacity figures are based on properly equipped vehicles and vary by configuration. Do not exceed any weight rating. See your owner's manual and the vehicle's door-jamb label for specific capacities.
Sources: GMC newsroom, Sept. 22, 2026, GM order guide summary, gm-trucks.com
Published AT4X Weights
| Specification | AT4X, Crew Cab 4WD |
|---|---|
| Base curb weight, Duramax diesel | 6,210 lbs |
| Base curb weight, 6.6L V8 | 6,050 lbs |
| Maximum GVWR | 7,500 lbs |
GMC says payload varies with engine, drive type, optional equipment, and whether the suspension is lifted. Configure your truck on our Build Your Own GMC page, then check the door-jamb label for its exact capacities.
Maximum towing and payload capacity figures are based on properly equipped vehicles and vary by configuration. Do not exceed any weight rating. See your owner's manual and the vehicle's door-jamb label for specific capacities.
Sources: GMC newsroom, Sept. 22, 2026, GMC.com 2027 Sierra 1500
Off-Road Hardware: What the AT4X Adds
Both trims ride on a 2-inch factory lift. These are the differences that matter once the pavement ends.
Suspension and Dampers
The AT4 uses monotube shocks. The AT4X steps up to Multimatic DSSV dampers plus new Jounce Control Dampers, which GMC says better manage big hits and hard landings to keep the truck more stable over rough terrain.
Sources: GMC.com 2027 Sierra 1500, GMC newsroom, Sept. 22, 2026
Locking Differentials
The AT4 has an auto-locking rear differential. The AT4X adds electronic locking differentials at both axles, a combination GMC says no competitor in its class offers.1
1Based on latest competitive data available. Excludes other GM vehicles.
Sources: GMC.com 2027 Sierra 1500, GMC newsroom, Sept. 22, 2026
Tires
The AT4X's Goodyear Wrangler Territory MT tires are a Sierra first, according to GMC, and are exclusive to the AT4X.
Sources: GMC newsroom, June 2026, GMC.com 2027 Sierra 1500
Baja Drive Mode
Baja drive mode is standard on the AT4X, and GMC lists it as AT4X-exclusive. It replaces Sport mode and is designed for high-speed off-road desert driving, optimizing throttle response, gear selection, damper tuning, and stability and traction control for rough terrain, sand, and loose surfaces.
Sources: GMC newsroom, Sept. 22, 2026, GMC.com 2027 Sierra 1500
Underbody Cameras
Front and rear underbody camera views show what is beneath the truck, and each camera has a wash function to keep the lens clear. They are standard on the AT4X and available on the AT4.
Sources: GMC.com 2027 Sierra 1500, GMC newsroom, Sept. 22, 2026
AT4X AEV Edition
For more protection, GMC offers the AT4X AEV Edition, which has late availability. It adds:
- AEV front and rear bumpers
- Skid plates
- Recovery hooks
- Black sport steps
- 18-inch beadlock-capable wheels
- All-weather floor liners
- Dual downturn exhaust
- AEV badging
Sources: GMC newsroom, Sept. 22, 2026, GMC newsroom, June 2026
AT4 and AT4X Technology and Comfort
Super Cruise Hands-Free Driving
| Super Cruise | AT4 and AT4X |
|---|---|
| Availability | Standard on both trims |
| Trailering | Hands-free trailering capability |
| OnStar plan | Includes 3 years of OnStar One; an active service plan is required |
| Lane changes while trailering | Automatic Lane Change and Turn Signal Activated Lane Change are not available |
| Where it works | Compatible roads in the U.S. and Canada |
Learn more on our Super Cruise page.
Turn Signal Activated Lane Change and Automatic Lane Change not available while trailering. Always pay attention while driving and when using Super Cruise. Always use Super Cruise in accordance with local laws. Do not use a hand-held device. Requires an active service plan. Terms apply. Visit gmc.com/explore-gmc/technology/super-cruise for compatible roads and full details.
Sources: GMC Super Cruise, GMC newsroom, Sept. 22, 2026, GM Super Cruise coverage
Screens
The 2027 Sierra 1500 introduces a 16.3-inch center touchscreen and a 12.2-inch Driver Information Center, both listed as standard on the AT4.
Sources: GMC newsroom, Sept. 22, 2026
Interior and Seating
| Feature | Sierra AT4 | Sierra AT4X | Edge |
|---|---|---|---|
| Front seats | 12-way power, heated and ventilated | 14-way power, heated, ventilated and massaging | AT4X |
| Steering wheel | Heated flat-bottom sport | Heated flat-bottom sport | Tie |
| Interior theme | Forest Storm | Timber Mahogany with Carbon Fiber accents | Personal preference |
The AT4X also includes a standard panoramic sunroof.
Sources: GMC.com 2027 Sierra 1500, GMC newsroom, Sept. 22, 2026
Which Sierra Off-Road Trim Is Right for You?
| If you want... | Better fit |
|---|---|
| The lower entry point shown in the table above | AT4 |
| A standard V8, with the option to add the diesel | AT4 |
| Daily driving and light-to-moderate trail use | AT4 |
| The Duramax diesel and larger fuel tank as standard | AT4X |
| Locking differentials at both axles | AT4X |
| Mud-terrain tires and Multimatic dampers | AT4X |
| Baja drive mode for high-speed loose-surface driving | AT4X |
| Massaging seats, 16-speaker audio, and a front passenger screen as standard | AT4X |
The verdict: both are capable off-road Sierras. The AT4 fits drivers who split time between pavement and trails, and the AT4X fits drivers who regularly take on technical terrain and want the hardware GMC builds for it. If trailering drives your decision, confirm the numbers for the exact truck before choosing a trim. The best way to decide is a back-to-back drive. See our new GMC Sierra 1500 inventory, or review every matchup on our GMC comparison page.
AT4 and AT4X Warranty Coverage
Coverage terms can vary by engine and model year, so confirm the terms for the exact truck.
| Coverage | Term |
|---|---|
| Bumper-to-bumper limited warranty | 3 years/36,000 miles |
| Powertrain limited warranty | 5 years/60,000 miles |
| Duramax Turbo-Diesel engines (AT4X standard, AT4 optional) | 5 years/100,000 miles |
| Roadside assistance | 5 years/60,000 miles |
| Courtesy transportation | 5 years/60,000 miles |
This information is provided for general educational purposes only and does not constitute legal advice. Warranty coverage depends on the specific terms of your vehicle's warranty agreement. Consult your owner's manual or a qualified legal professional for guidance on your individual situation.
Sources: GMC warranty, GMC powertrain, GMC roadside and courtesy transportation, GM Limited Warranty and Owner Assistance Information
See Both Trims at Lynch GMC of Burlington
- Address: 2300 Browns Lake Drive, Burlington, WI 53105
- Sales: 262-661-2234
- Serving: Burlington, Rochester, Waterford, East Troy, and nearby communities
Call to ask about arriving 2027 AT4 and AT4X inventory, or explore the 2027 next-generation Sierra 1500 overview and our GMC research guides.
GMC AT4 and AT4X FAQs
Does the 2027 GMC Sierra AT4 come standard with Super Cruise?
Yes. Super Cruise with trailering capability is standard on the AT4 and AT4X, along with the Denali and Denali Ultimate trims. Lane-change functions are not available while trailering.
Turn Signal Activated Lane Change and Automatic Lane Change not available while trailering. Always pay attention while driving and when using Super Cruise. Always use Super Cruise in accordance with local laws. Do not use a hand-held device. Requires an active service plan. Terms apply. Visit gmc.com/explore-gmc/technology/super-cruise for compatible roads and full details.
Does the Sierra AT4X have a special drive mode?
Yes. Baja drive mode is standard on the AT4X and is designed for high-speed off-road desert driving. GMC lists it as AT4X-exclusive, so the AT4 does not offer it.
What warranty covers the GMC Sierra off-road trims?
GMC lists a 3-year/36,000-mile limited warranty, a 5-year/60,000-mile powertrain limited warranty, and 5-year/60,000-mile roadside assistance with courtesy transportation. GM's warranty information lists Duramax diesel engines at 5 years/100,000 miles, so confirm the coverage for the exact truck.
This information is provided for general educational purposes only and does not constitute legal advice. Warranty coverage depends on the specific terms of your vehicle's warranty agreement. Consult your owner's manual or a qualified legal professional for guidance on your individual situation.
Can the AT4X tow a boat or travel trailer?
The AT4X is built for trailering. GMC has not published a trim-level towing rating for it, and the Max Trailering Package is not offered on the AT4X, so confirm the rating and payload for the exact truck using the towing table above and the door-jamb label.
Maximum towing and payload capacity figures are based on properly equipped vehicles and vary by configuration. Do not exceed any weight rating. See your owner's manual and the vehicle's door-jamb label for specific capacities.
What is the fuel tank capacity on the 2027 GMC Sierra AT4X?
The AT4X comes standard with an approximately 34-gallon fuel tank and the Duramax diesel.
Disclaimers
- MSRP: Manufacturer's Suggested Retail Price (MSRP) for new vehicles includes manufacturer and distributor options and delivery, process and handling fees, which may be subject to change at any time. MSRP excludes taxes, title, license and dealer installed options, accessories, fees and charges. MSRP is not the dealer advertised price. Dealer price will vary. The dealer sets the final price.
- Fuel economy: EPA-estimated fuel economy figures are for comparison purposes only. Your actual mileage will vary depending on driving conditions, how you drive and maintain your vehicle, battery age/condition, and other factors.
- Towing and payload: Maximum towing and payload capacity figures are based on properly equipped vehicles and vary by configuration. Do not exceed any weight rating. See your owner's manual and the vehicle's door-jamb label for specific capacities.
- Warranty: This information is provided for general educational purposes only and does not constitute legal advice. Warranty coverage depends on the specific terms of your vehicle's warranty agreement. Consult your owner's manual or a qualified legal professional for guidance on your individual situation.
- Super Cruise: Turn Signal Activated Lane Change and Automatic Lane Change not available while trailering. Always pay attention while driving and when using Super Cruise. Always use Super Cruise in accordance with local laws. Do not use a hand-held device. Requires an active service plan. Terms apply. Visit gmc.com/explore-gmc/technology/super-cruise for compatible roads and full details.
- Competitive claims: Based on latest competitive data available. Excludes other GM vehicles.
- Model year and sources: 2027 Sierra 1500 specifications and availability are preliminary and subject to change. Sources: GMC, "GMC Announces Full Specifications for the Next-Generation 2027 Sierra 1500," September 22, 2026; GMC.com 2027 Sierra 1500; EPA fueleconomy.gov 2027 GMC fuel economy; GMC warranty information; GMC Super Cruise.