Chevrolet and GMC share the same heavy duty platform. The Silverado HD and Sierra HD are mechanically identical trucks sold under different nameplates. The 4500HD and 5500HD are chassis cab–only commercial platforms introduced for the 2020 model year.
| Generation | Years | Brands | Engines | Key Changes & Milestones |
|---|---|---|---|---|
| Gen 1 HD | 2011–2014 | Silverado / Sierra 3500HD | 6.0L Gas / 6.6L Duramax LML | Duramax LML at 397hp/765lb-ft; 6-speed Allison auto; max tow ~21,700 lb |
| Gen 2 HD | 2015–2019 | Silverado / Sierra 3500HD | 6.0L Gas / 6.6L Duramax L5P | Refreshed body; new L5P Duramax (2017) 445hp/910lb-ft; tow up to 23,300 lb |
| Gen 3 HD | 2020–2023 | Silverado / Sierra 3500/4500/5500HD | 6.6L Gas / 6.6L Duramax L5P | All-new body; new 6.6L gas V8; Duramax to 470hp/975lb-ft; 4500/5500 debut; tow up to 36,000 lb |
| Gen 3R | 2024–present | Silverado / Sierra 3500/4500/5500HD | 6.6L Gas / 6.6L Duramax L5P | Refreshed styling; Google built-in; Super Vision mirrors; ratings maintained |
Chevrolet Silverado HD and GMC Sierra HD are mechanically identical — all specs apply to both brands.
4500HD and 5500HD chassis cab models were introduced for the 2020 model year.
| Model | Regular Cab | Double Cab (Ext.) | Crew Cab | Chassis Cab |
|---|---|---|---|---|
| 3500HD (Silverado/Sierra) | Yes (2011–present) | Yes (2011–present) | Yes (2011–present) | Yes (2011–present) |
| 4500HD (Silverado/Sierra) | No | No | Yes (2020–present) | Yes – Primary Config |
| 5500HD (Silverado/Sierra) | No | No | Yes (limited) | Yes – Primary Config |
| Bed Lengths (3500HD pickup) | 6.5 ft / 8 ft | 6.5 ft / 8 ft | 6.5 ft / 8 ft | N/A (varies by body) |
| 4x2 Available | Yes | Yes | Yes | Yes |
| 4x4 Available | Yes | Yes | Yes | Yes (3500/4500); limited 5500 |
DRW = Dual Rear Wheel; SRW = Single Rear Wheel. 3500HD available in both; 4500HD/5500HD are DRW only.
Chassis Cab models ship without a bed — upfitters install flatbeds, service bodies, dump beds, utility boxes, etc.
| Year Range | Engine | Fuel | Horsepower | Torque | Transmission | Drivetrain |
|---|---|---|---|---|---|---|
| 2011–2016 | 6.0L Vortec V8 Gas | Gas | 360 hp | 380 lb-ft | 6-speed auto | 2WD / 4WD |
| 2011–2016 | 6.6L Duramax LML V8 Turbo Diesel | Diesel | 397 hp | 765 lb-ft | 6-speed Allison auto | 2WD / 4WD |
| 2017–2019 | 6.6L Duramax L5P V8 Turbo Diesel | Diesel | 445 hp | 910 lb-ft | 6-speed Allison auto | 2WD / 4WD |
| 2020–present | 6.6L Vortec V8 Gas (L8T) | Gas | 401 hp | 464 lb-ft | 6-speed auto | 2WD / 4WD |
| 2020–present | 6.6L Duramax L5P V8 Turbo Diesel | Diesel | 470 hp | 975 lb-ft | 10-speed Allison auto | 2WD / 4WD |
The 6.6L Duramax is always paired with the Allison transmission — the only factory Allison pairing in the heavy duty pickup segment.
2020+ models upgraded to a 10-speed Allison 10L1000 automatic with the Duramax diesel.
| Feature | 4WD (4x4) | 2WD (4x2) |
|---|---|---|
| Available Models | 3500HD, 4500HD (limited), 5500HD (limited) | 3500HD, 4500HD, 5500HD |
| Transfer Case | Autotrac / Active 2-speed (2H / 4H / 4L) | Not applicable |
| Front Axle (3500HD) | AAM 9.25" IFS (SRW) / AAM 10.5" Solid (DRW) | No front drive axle |
| Front Axle (4500/5500HD) | AAM 11.5" solid front axle | No front drive axle |
| Rear Axle (3500HD) | AAM 11.5" (DRW) / AAM 9.76" (SRW) | AAM 11.5" (DRW) / AAM 9.76" (SRW) |
| Rear Axle (4500/5500HD) | AAM 13" / AAM 14.5" | AAM 13" / AAM 14.5" |
| Payload Impact | Reduced 300–600 lb vs. 2WD | Higher payload rating |
| Towing Impact | Slightly lower max tow rating | Slightly higher max tow rating |
| Best For | Off-road, snow, mud, Colorado mountain terrain | Highway, urban fleet, construction |
| GVWR (3500HD) | Up to 14,000 lb | Up to 14,000 lb |
| GVWR (4500HD) | Up to 16,500 lb | Up to 16,500 lb |
| GVWR (5500HD) | Up to 19,500 lb | Up to 19,500 lb |
4WD adds approximately 300–500 lb of curb weight vs. 2WD, reducing payload ratings accordingly.
Payload is the maximum weight carriable in the cab and bed, or on the chassis. Always verify the yellow door-jamb sticker for your specific truck.
| Model | Cab Style | Drive | Engine | Max Payload Capacity |
|---|---|---|---|---|
| 3500HD DRW | Regular Cab | 4x2 | 6.6L Duramax | ~7,442 lb |
| 3500HD DRW | Regular Cab | 4x2 | 6.6L Gas | ~6,570 lb |
| 3500HD DRW | Crew Cab | 4x4 | 6.6L Duramax | ~5,530 lb |
| 3500HD SRW | Crew Cab | 4x4 | 6.6L Duramax | ~3,090 lb |
| 3500HD Chassis | Regular Cab | 4x2 | 6.6L Duramax | ~9,100 lb |
| 4500HD | Crew Cab | 4x4 | 6.6L Duramax | ~7,200 lb |
| 4500HD | Chassis Cab | 4x2 | 6.6L Duramax | ~12,900 lb (body-dependent) |
| 5500HD | Chassis Cab | 4x2 | 6.6L Duramax | ~17,500 lb (upfitter body) |
| 5500HD | Chassis Cab | 4x4 | 6.6L Duramax | ~15,500 lb (approx.) |
Actual payload on your specific truck is on the yellow sticker inside the driver door jamb (GVWR minus curb weight).
4500HD/5500HD Chassis Cab payload is highly dependent on the upfitter body installed and its weight.
The Silverado/Sierra 3500HD holds the segment record for 5th wheel towing at 36,000 lb (2020+, properly equipped). The factory Allison transmission is a unique advantage in the segment.
| Model | Cab | Drive | Engine | Conventional | 5th Wheel | Gooseneck |
|---|---|---|---|---|---|---|
| Rear receiver | Bed pin box | Bed ball | ||||
| 3500HD SRW | Regular Cab | 4x2 | 6.6L Duramax | 20,000 lb | N/A | N/A |
| 3500HD SRW | Crew Cab | 4x4 | 6.6L Duramax | 18,500 lb | N/A | N/A |
| 3500HD SRW | Crew Cab | 4x4 | 6.6L Gas | 17,000 lb | N/A | N/A |
| 3500HD DRW | Regular Cab | 4x2 | 6.6L Duramax | 20,000 lb | 36,000 lb | 36,000 lb |
| 3500HD DRW | Crew Cab | 4x4 | 6.6L Duramax | 18,500 lb | 32,000 lb | 32,000 lb |
| 3500HD DRW | Crew Cab | 4x2 | 6.6L Duramax | 19,000 lb | 34,000 lb | 34,000 lb |
| 4500HD | Crew Cab | 4x4 | 6.6L Duramax | 18,500 lb | 24,000 lb | 24,500 lb |
| 4500HD | Chassis Cab | 4x2 | 6.6L Duramax | 20,500 lb | 26,000 lb | 26,500 lb |
| 4500HD | Chassis Cab | 4x4 | 6.6L Duramax | 18,500 lb | 24,500 lb | 25,000 lb |
| 5500HD | Chassis Cab | 4x2 | 6.6L Duramax | 19,000 lb | 25,500 lb | 26,000 lb |
| 5500HD | Chassis Cab | 4x4 | 6.6L Duramax | 17,500 lb | 23,500 lb | 24,000 lb |
| 5500HD | Chassis Cab | 4x2 | 6.6L Gas | 14,500 lb | 18,500 lb | 18,500 lb |
Silverado/Sierra 3500HD DRW holds the segment record for 5th wheel towing at 36,000 lb (2020+, Duramax, properly equipped).
5th wheel and gooseneck ratings require the factory tow prep package or an approved aftermarket hitch system.
Always verify the specific tow rating on your truck's door-jamb sticker — it is the legally binding figure for your build.
Highlighted rows mark major capacity jumps. The 2017 L5P Duramax and the 2020 full redesign delivered the biggest towing increases in this platform's history.
| Year | 3500HD DRW Conv. | 3500HD DRW 5W/GN | 4500HD GN | 5500HD GN | Engine / Notes |
|---|
Highlighted years (2014, 2017, 2020) mark major powertrain or chassis upgrades.
4500HD and 5500HD were not offered until 2020 — prior years show N/A.
5W = 5th Wheel | GN = Gooseneck | Conv. = Conventional rear-receiver hitch
| Use Case | Recommended Config | Key Reason |
|---|---|---|
| Max 5th wheel towing | 3500HD DRW Regular Cab, 4x2, Duramax | Segment-record 36,000 lb 5W rating (2020+) |
| Heavy gooseneck towing | 3500HD DRW, 4x2, Duramax | Up to 36,000 lb GN with proper hitch |
| Commercial work body | 5500HD Chassis Cab, 4x2, Duramax | Highest GVWR, max payload for upfitter body |
| Farm / ranch / off-road tow | 3500HD DRW Crew Cab, 4x4, Duramax | 4WD + high tow capacity + Allison trans |
| Daily driver + weekend towing | 3500HD SRW Crew Cab, 4x4, Duramax or Gas | Comfortable ride, car-like interior, versatile |
| Fleet / highway work truck | 4500HD Chassis Cab, 4x2, Duramax | Best payload/tow balance for commercial fleet |
| Best luxury + capability | Sierra 3500HD Denali, 4x4, Duramax | Top-tier interior + segment-leading tow capacity |
All specifications are based on General Motors published data for U.S.-market vehicles (2011–2025 model years). Towing and payload capacities represent maximum available ratings for optimally configured trucks; your specific vehicle's ratings may differ. Always consult the vehicle's door-jamb sticker, owner's manual, and an authorized Chevrolet or GMC dealer for precise specifications. Upfitter-installed bodies may affect rated capacities. Chevrolet, GMC, Duramax, and Allison are registered trademarks of their respective owners.
