The towing capacity in the 2018 GMC Sierra 1500 ranges from 5,500 – 12,500 lbs. This is dependent on the cab size, bed size, drive, package, and most importantly engine.
The highest towing capacity in the 2018 GMC Sierra 1500 of 12,500 lbs is achieved with the 4WD 6.2 L V8 engine, Double Cab, Standard Bed and Max Trailering Package.
You should always use your own data to determine your towing capacity by calculating towing capacity on your own by using the weight capacities listed in your truck door.
Information in this guide was taken from the 2018 GMC Sierra 1500 Owner’s Manual, the 2018 GMC Sierra 1500 Diesel Supplement, 2018 GMC Sierra 1500 Specifications Sheet, 2018 GMC Sierra 1500 Trailering Guide, and the 2018 GMC Sierra 1500 ebrochure.
Though I tried to make this information as accurate as possible, you should always check your manual or contact your local dealer to determine the appropriate towing capacity of your vehicle and necessary equipment.
2018 GMC Sierra 1500 Engine Performance
There are 3 available engines in the GMC Sierra 1500. Not every trim is available with each engine, but there are definitely a lot of choices.
We will walk you through the specs of each to help you decide what engine you want, or identify what engine you have if you already have your truck.
There is the 4.3 L V8, 5.3 L V8, and 6.2 LV8.
The 2.7 L turbo engine in the 2018 GMC Sierra 1500 provides 310 hp and 348 lb-ft of torque.
4.3 L V8 Engine
The 4.3 L V8 engine has a torque of 305 lb.-ft. @ 3,900 rpm and 285 hp @ 5,300 rpm.
Depending on the compatibility, this engine has a max towing capacity of 7,900 lbs.
This engine comes with either a 6-speed or 8-speed transmission which impacts the towing and payload capacities slightly.
5.3 L V8 Engine
The 5.3 L V8 engine in the 2018 GMC Sierra 1500 provides 355 hp and 383 lb-ft of torque.
This engine is a 6 speed automatic engine that is also available in an 8 and 10 speed option.
This engine comes standard on the SLT, AT4, and Denali but is available with the SLE and Elevation.
6.2 L V8 Engine
The 6.2 L V8 engine in the 2018 GMC Sierra 1500 provides 420 hp and 460 lb-ft of torque.
It is a 10 speed automatic engine that is available in 4WD on the SLT, AT4 and Denali.
Towing Packages
There are two packages available in the 2018 GMC Sierra 1500.
The Trailering Package and the Max Trailering Package.
Trailering Package
The Trailering Package in the 2018 GMC Sierra 1500 comes with:
- Weight distributing hitch platform
- Hitch ball
- Electrical harness
This package has no influence on the max towing capacity, but it makes the GMC Sierra capable of towing because it provides the necessary equipment.
Max Trailering Package
The Max Trailering Package, unlike the regular Trailering Package, provides additional features that improve the overall towing capacity when in use. It includes:
- Trailering Package
- 3.42 axle ratio
- 9.76″ Rear Axle
- Enhanced cooling radiator
- Revised shock tuning
- Heavy-duty rear springs
- Increased Rear Gross Axle Weight Ratting
- 220 amp alternator
This package is only available on the SLE, Elevation and SLT trims.
Max Towing Capacity by Engine
To determine the towing capacity of your vehicle, you need to know the:
- engine type
- bed size
- cab size
- drivetrain
- axle ratio
If you know all of these items, then move on to the next section by engine to determine your towing capacity.
If not:
- Start with the VIN decoder from Autozone to determine the engine in the vehicle
- measure the bed size with a tape measure to determine whether you have a 5 ft 9.9 in, 6 ft 7 in, or 8 ft bed
- The cab size should be evident by whether or not the back doors are full-sized
- Drivetrain should be determined with the VIN as well
- The axle ratio will likely be listed on the side of the driver’s door on the certification sticker
You can find the GVWR and usually the axle ratio on the Safety Compliance Certification Label on the inside of the driver’s side door.
Related: What is GVWR?
4.3 L V6 Engine
The 4.3L V6 engine towing capacity in the 2018 GMC Sierra 1500 ranges from 5,500 – 7,600 lbs.
| Towing Capacity (lbs) | Est. GCWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 5,500/7,000 | 10,500/12,300 |
| Double Cab Standard Bed 4×2/4×4 | 5,600/7,100 | 7,900/12,300 |
| Regular Cab Standard Bed 4×2/4×4 | 6,000/7,600 | 10,700/12,600 |
| Regular Cab Long Bed 4×2/4×4 | 5,900/7,400 | 10,600/12,700 |
5.3 L V8 Engine
The 5.3 L V8 engine towing capacity in the 2018 Next Generation GMC Sierra 1500 ranges from 6,100 – 9,800 lbs without the Max Trailering Package and up to 11,100 lbs with the Max Trailering Package.
| Max Trailering Package/Axle Ratio | Other Packages | Towing Capacity (lbs) | Est. GCWR (lbs) | |
| Crew Cab Short Bed 4×2 | /(3.08/3.42) | 6,400/9,400 | 11,400/14,700 | |
| Crew Cab Short Bed 4×2 8-speed automatic transmission | /3.42 | 9,300 | 14,300 | |
| Crew Cab Short Bed 4×4 | /(3.08/3.42) | 6,100/9,100 | 11,400/14,400 | |
| Crew Cab Short Bed (4×2/4×4)) | X/(3.42/3.73) | 11,000/10,700 | 16,000/16,000 | |
| Crew Cab Short Bed (4×2/4×4) | /3.42 | E-Assist Package | 9,400/9,100 | 14,400/14,400 |
| Crew Cab Standard Bed 4×4 | /(3.08/3.42) | 6,100/9,100 | 11,400/14,400 | |
| Crew Cab Standard Bed (4×4) | X/(3.42/3.73) | 10,700/10,700 | 16,000 | |
| Double Cab Standard Bed (4×2) | /(3.08/3.42) | 6,400/9,400 | 11,400/14,400 | |
| Double Cab Standard Bed 4×4 | /(3.08/3.42) | 6,200/9,200 | 11,400/14,400 | |
| Double Cab Standard Bed (4×2/4×4) | X/(3.42/3.73) | 11,100/11,100 | 16,000/16,000 | |
| Regular Cab Standard Bed 4×2 | /(3.08/3.42) | 6,900/8,900 | 11,600/13,600 | |
| Regular Cab Standard Bed 4×4 | /(3.08/3.42) | 6,600/8,600 | 11,500/13,300 | |
| Regular Cab Long Bed 4×2 | /(3.08/3.42) | 6,800/9,800 | 11,500/14,500 | |
| Regular Cab Long Bed 4×4 | /(3.08/3.42) | 6,500/9,500 | 11,500/14,500 |
SIERRA DENALI TOWING CAPACITY FOR THE 5.3L V8 ENGINE
The 2018 Sierra Denali towing capacity ranges from 9,100 – 9,300 lbs.
| Axle Ratio | Towing Capacity (lbs) | Est. GCWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 3.42 | 9,300/9,100 | 14,600/14,400 |
| Crew Cab Standard Bed 4×4 | 3.42 | 9,100 | 14,400 |
6.2 L V8 Engine
The 6.2 L V8 engine towing capacity in the 2018 GMC Sierra 1500 ranges from 9,000 – 12,500 lbs with the Max Trailering Package.
| Max Trailering Package/Axle Ratio | Towing Capacity (lbs) | Est. GCWR (lbs) | |
| Crew Cab Short Bed 4×2/ 4×4 | /3.23 | 9,300/9,100 | 14,400/14,400 |
| Crew Cab Short Bed 4×2/4×4 | X/3.42 | 12,500/11,700 | 17,500/17,000 |
| Crew Cab Standard Bed 4×4 | /3.23 | 9,000 | 14,300 |
| Crew Cab Standard Bed 4×4 | X/3.42 | 11,700 | 17,000 |
| Double Cab Standard Bed 4×2/4×4 | /3.23 | 9,400/9,100 | 14,400/14,400 |
| Double Cab Standard Bed 4×2/4×4 | X/3.42 | 12,500/11,800 | 17,500/17,000 |
SIERRA DENALI TOWING CAPACITY FOR THE 6.2L V8 ENGINE
The 2018 Sierra Denali towing capacity ranges from 9,000 – 9,300 lbs.
| Axle Ratio | Towing Capacity (lbs) | Est. GCWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 3.23 | 9,300/9,100 | 14,300/14,400 |
| Crew Cab Standard Bed 4×4 | 3.23 | 9,000 | 14,300 |
2018 GMC Sierra 1500 Towing Capacity Chart
2018 GMC Sierra 1500 Fifth Wheel/Gooseneck Towing Capacity
Fifth wheel towing and gooseneck towing are compatible with the 2018 GMC Sierra 1500. The charts below lists all towing capacities, payload capacities and the fifth wheel/gooseneck capacities.
2018 GMC Sierra 1500 Payload Capacity
4.3 L V6 Engine
The 4.3 L V6 engine payload capacity in the 2018 GMC Sierra 1500 ranges from 1,930 – 2,250 lbs.
| Payload Capacity (lbs) | GVWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 2,170/2,120 | 7,400/7,600 |
| Double Cab Standard Bed 4×2/4×4 | 2,250/2,220 | 7,400/7,600 |
| Regular Cab Standard Bed 4×2/4×4 | 1,980/1,930 | 6,800/7,000 |
| Regular Cab Long Bed 4×2/4×4 | 1,980/1,930 | 6,800/7,000 |
5.3 L V8 Engine
The 5.3 L V8 engine payload capacity in the 2018 GMC Sierra 1500 ranges from 1,930 – 2,250 lbs with and without the Max Trailering Package.
| Max Trailering Package/Axle Ratio | Other Packages | Payload Capacity (lbs) | GVWR (lbs) | |
| Crew Cab Short Bed 4×2 | /(3.08/3.42) | 2,170 | 7,400 | |
| Crew Cab Short Bed 4×2 8-speed automatic transmission | /3.42 | 2,170 | 7,400 | |
| Crew Cab Short Bed 4×4 | /(3.08/3.42) | 2,120 | 7,600 | |
| Crew Cab Short Bed (4×2/4×4)) | X/(3.42/3.73) | 2,170/2,120 | 7,400/7,600 | |
| Crew Cab Short Bed (4×2/4×4) | /3.42 | E-Assist Package | 2,170/2,120 | 7,400/7,600 |
| Crew Cab Standard Bed 4×4 | /(3.08/3.42) | 2,120 | 7,600 | |
| Crew Cab Standard Bed (4×4) L84 | X/(3.42/3.73) | 2,120 | 7,600 | |
| Double Cab Standard Bed (4×2) | /(3.08/3.42) | 2,250 | 7,400 | |
| Double Cab Standard Bed 4×4 | /(3.08/3.42) | 2,220 | 7,600 | |
| Double Cab Standard Bed (4×2/4×4) | X/(3.42/3.73) | 2,250/2,220 | 7,400/7,600 | |
| Regular Cab Standard Bed 4×2 | /(3.08/3.42) | 1,980 | 6,800 | |
| Regular Cab Standard Bed 4×4 | /(3.08/3.42) | 1,930 | 7,000 | |
| Regular Cab Long Bed 4×2 | /(3.08/3.42) | 1,980 | 6,800 | |
| Regular Cab Long Bed 4×4 | /(3.08/3.42) | 1,930 | 7,000 |
SIERRA DENALI PAYLOAD CAPACITY FOR THE 5.3L V8 ENGINE
The 2018 Sierra Denali payload capacity ranges from 2,120 – 2,170 lbs.
| Axle Ratio | Payload Capacity (lbs) | GVWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 3.42 | 2,170/2,120 | 7,400/7,600 |
| Crew Cab Standard Bed 4×4 | 3.42 | 2,120 | 7,600 |
6.2 L V8 Engine
The 6.2 L V8 engine payload capacity in the 2018 GMC Sierra 1500 ranges from 2,120 – 2,250 lbs.
| Max Trailering Package/Axle Ratio | Payload Capacity (lbs) | GVWR (lbs) | |
| Crew Cab Short Bed 4×2/ 4×4 | /3.23 | 2,170/2,120 | 7,400/7,600 |
| Crew Cab Short Bed 4×2/4×4 | X/3.42 | 2,170/2,120 | 7,400/7,600 |
| Crew Cab Standard Bed 4×4 | /3.23 | 2,120 | 7,600 |
| Crew Cab Standard Bed 4×4 | X/3.42 | 2,120 | 7,600 |
| Double Cab Standard Bed 4×2/4×4 | /3.23 | 2,250/2,220 | 7,400/7,600 |
| Double Cab Standard Bed 4×2/4×4 | X/3.42 | 2,250/2,220 | 7,400/7,600 |
SIERRA DENALI PAYLOAD CAPACITY FOR THE 6.2L V8 ENGINE
The 2018 Sierra Denali payload capacity for the 6.2L V8 ranges from 2,120 – 2,170 lbs.
| Axle Ratio | Payload Capacity (lbs) | GVWR (lbs) | |
| Crew Cab Short Bed 4×2/4×4 | 3.23 | 2,170/2,120 | 7,400/7,600 |
| Crew Cab Standard Bed 4×4 | 3.23 | 2,170/2,120 | 7,400/7,600 |
GMC Sierra 1500 Tongue Weight
GMC recommends that the hitch weight for conventional towing should be 10%-15% of the loaded trailer weight. More so, the fifth-wheel or gooseneck tongue weight should be 15% – 25% of the total loaded trailer weight.
The max tongue weight for conventional trailer hitch is 1,250 lbs.
A loaded trailer exceeding 2,000 lbs must be equipped with its own brake system, with brakes working on all axles. Any trailer weight over 7,000 lbs requires a weight-distributing hitch.
You must make sure you have the appropriate hitch receiver to accommodate the towing capacity you are targeting.
2018 GMC Sierra 1500 Trims
The GMC Sierra 1500 in 2018 family has 7 trims.
- Sierra
- SLE
- Elevation
- SLT
- All Terrain
- Denali
- Elevation Edition SLE
Each of these models has various options for customization, engine selection, cab size, and bed size.
GMC Sierra 1500 Cab Sizes
The 2018 GMC Sierra 1500 has three cab sizes. These are the Regular cab, Double cab, and Crew cab.
The Regular Cab has only one row of seating but the other two options have two rows and can seat up to 6 passengers.
The Crew cab is the largest cab and provides the most back seat legroom for passengers.
The regular cab is only compatible with the long bed and the double cab is only available with the standard bed.
GMC Sierra 1500 Bed Sizes
The GMC Sierra 1500 has three bed sizes. They have a 5’8″ bed, a 6’6″ bed, and an 8′ bed. These beds are referred to as the short, standard, and long bed respectively.
The 8′ bed is only available with the Regular Cab.
This bed type is a fleetside truck meaning that the wheel wells stick out into the bed of the truck making the shape no longer perfectly rectangular. This is very common for trucks.
Conclusion
The 2018 GMC Sierra 1500 has a towing capacity ranging from 5,500 – 12,500 lbs.
The engine type, drive, cab size, and bed size can all impact the towing capacity.
You should always do your own towing capacity calculations before you ever tow anything, especially those that are close to these limits.
If you need help calculating your towing capacity, I wrote an entire article that walks you through the steps to calculate your towing capacity along with other considerations you need to make when towing.
