GMC Sierra 1500 trim comparison
2025 GMC Sierra 1500 AT4 vs Denali Ultimate
The Sierra 1500 AT4 starts at $66,800 while the Denali Ultimate is $84,200. That $17,400 gap buys 6 meaningful differences.
This trim jump changes the engine from 3.0L I6 diesel Turbo to 6.2L V8. Everything else is secondary to whether that powertrain difference matters for how you drive.
Start with the AT4 if the 3.0L I6 diesel Turbo already feels sufficient for the way you drive. Step up to the Denali Ultimate only when the 6.2L V8 powertrain is the reason you are moving higher in the lineup.
If you are budgeting this move monthly, the jump from the AT4 to the Denali Ultimate is about $307/month on a 60-month loan at 6.5% APR with 10% down. That works out to roughly $18,420 more by the time interest is counted. The payment only makes sense if that different powertrain matters to the way you actually drive, tow, or live with the vehicle.
Lock one trim, change the other side, and move through exact pair pages without resetting back to the full lineup every time.
Who notices the difference
The higher trim starts to make more sense when you tow, haul, or merge with enough load that the stronger powertrain matters.
When both feel the same
Both the AT4 and Denali Ultimate share the same 10-speed shiftable automatic transmission.
The upgrade math
You are paying $17,400 for 5 measurable differences, which works out to about $3,480 per change.
Key Differences at a Glance
This is the fast read: price, power, efficiency, and the feature flips most likely to change the answer.
Every Difference, Side by Side
This is the full read behind the quick decision signals above: the complete hardware, comfort, and equipment story. 6 specification differences, 1 shared.
Full Specification Comparison
Specifications reflect available data as of early 2025. Confirm details with an authorized dealer before purchasing.
| Spec | AT4 | Denali Ultimate |
|---|---|---|
| Pricing | ||
| MSRP | $66,800 | $84,200 |
| Powertrain | ||
| Engine | 3.0L I6 diesel Turbo | 6.2L V8 |
| Horsepower | 305 hp | 420 hp |
| Torque | 495 lb-ft | 460 lb-ft |
| Transmission | 10-speed shiftable automatic | 10-speed shiftable automatic |
| Drivetrain | 4WD | 4WD |
| Fuel Economy | ||
| City MPG | 21 | 15 |
| Highway MPG | 24 | 19 |
| Combined MPG | 23 | 16 |
| Fuel Tank | 24.0 gal | 24.0 gal |
| Dimensions | ||
| Curb Weight | 5,500 lbs | 5,350 lbs |
| Wheelbase | 148.0" | 147.0" |
| Length | 232.9" | 231.9" |
| Width | 81.2" | 81.2" |
| Height | 78.4" | 75.5" |
| Truck Specs | ||
| Cab Type | Crew Cab | Crew Cab |
| Bed Length | 5.8 ft | 5.8 ft |
| Safety | ||
| NHTSA Overall | 5/5 stars | 5/5 stars |
| Warranty | ||
| Bumper-to-Bumper | 3yr/36k | 3yr/36k |
| Powertrain | 5yr/60k | 5yr/60k |
| Corrosion | 6yr/100k | 6yr/100k |
| Roadside Assistance | 5yr/60k | 5yr/60k |
Data sources: licensed third-party automotive data, EPA fueleconomy.gov, NHTSA, and official manufacturer materials. Values marked est. are estimated.
2025 GMC Sierra 1500 AT4 vs Denali Ultimate Questions Shoppers Ask
Use this page for the direct trim answer, then zoom back out to the GMC Sierra 1500 lineup, the GMC brand hub, the Full-Size Trucks, the how to pick a trim guide, or our mid-trim value research when you need the bigger shopping path behind this one matchup.
How much more does the 2025 Sierra 1500 Denali Ultimate cost than the AT4?
The Denali Ultimate starts at $84,200 compared to $66,800 for the AT4 (both Crew Cab 4WD). That is a $17,400 difference, or approximately $307/month more on a 60-month loan.
Do the 2025 GMC Sierra 1500 AT4 and Denali Ultimate have the same engine?
No. The AT4 uses a 3.0L I6 diesel Turbo (305 hp, 495 lb-ft), while the Denali Ultimate has the 6.2L V8 (420 hp, 460 lb-ft). That is 115 more horsepower. Both pair with the same 10-speed shiftable automatic.
Do the 2025 Sierra 1500 AT4 and Denali Ultimate have the same drivetrain?
Yes. Both come with 4WD as standard. The differences between these trims are in features and equipment, not drivetrain.
Is the 2025 Sierra 1500 AT4 or Denali Ultimate safer?
Both share the same GMC Sierra 1500 platform with an overall 5-star NHTSA safety rating. Safety ratings are model-level and identical across trims. The trim choice affects comfort and features, not crash protection.
What warranty does the 2025 GMC Sierra 1500 come with?
All 2025 GMC Sierra 1500 trims, including both the AT4 and Denali Ultimate, come with GMC's standard warranty: 3yr/36k bumper-to-bumper and 5yr/60k powertrain coverage. Warranty does not vary by trim level.
Is the 2025 GMC Sierra 1500 Denali Ultimate worth $17,400 more than the AT4?
The $17,400 buys the 6.2L V8. If that powertrain matters for how you drive, yes. If not, the AT4 does the same job for less.
Which 2025 GMC Sierra 1500 trim gets better fuel economy, the AT4 or the Denali Ultimate?
The AT4 is the more efficient of the two at 23 combined MPG, versus 16 for the other trim. That matters most if you are balancing running costs against the extra power, drivetrain, or comfort equipment tied to the pricier trim.
The Full Story Behind This Price Gap
Use the direct answer above for this exact matchup, then use these guides to understand whether you are really looking at a feature step-up, a package shuffle, or the point where the lineup starts changing in a meaningful way.
What $17,400 Gets You
The Sierra 1500 Denali Ultimate costs $17,400 more than the AT4. Whether that is worth it depends on how much you value the 6.2L V8 engine (+115 hp). Power and comfort matter differently to different buyers. Weigh them against your priorities.
AT4 vs. Denali Ultimate: Day-to-Day
The Denali Ultimate runs a 6.2L V8 instead of the AT4's 3.0L I6 diesel Turbo. That means 115 more horsepower and -35 more lb-ft of torque. You will feel the difference towing, merging, and passing on the highway. The cost of that extra capability is roughly 7 fewer combined MPG.
Fuel Economy Comparison
The Sierra 1500 AT4 gets 7 more combined MPG. At $3.50/gallon and 12,000 miles/year, that saves roughly $799 per year or $3,995 over five years of ownership.
Summary
$17,400 more for the Sierra 1500 Denali Ultimate gets you 5 real differences. At $307/month more, the question is whether those specific changes are things you will use regularly.
Trim-Matched Accessories
These add-ons are split by trim intent so the recommendations follow the actual use case, not just the same repeated product block.
GMC Sierra 1500 AT4
Value-trim add-onsThese picks fit the AT4 best when the goal is covering the daily-use gaps without paying up to the next trim.
GMC Sierra 1500 Denali Ultimate
Step-up trim add-onsThese picks suit the Denali Ultimate when you want the accessories to match the nicer cabin, broader utility, or more premium use case.
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Specifications shown combine licensed third-party automotive data with official manufacturer, EPA, and NHTSA source material for the 2025 model year. Actual pricing, features, and availability may vary by region and dealer. Always confirm details with an authorized dealer before making a purchase decision. TrimAtlas is not affiliated with GMC or any dealership.
Page updated 2026-03-18. Verify equipment, pricing, and regional availability with the manufacturer or dealer.