GMC Sierra 2018 Owner's Manual page 301

300 Driving and Operating
1500/2500/3500 Series Pickups
Vehicle
5.3L V8 Conventional Trailer
5.3L V8, 6-speed automatic
transmission Gooseneck/
Fifth-Wheel Trailer
5.3L V8, 8-speed automatic
transmission Gooseneck/
Fifth-Wheel Trailer
5.3L V8, 8-speed automatic
transmission with Enhanced
Towing Package Conventional
Trailer
5.3L V8, 8-speed automatic
transmission with Enhanced
Towing Package Gooseneck/
Fifth-Wheel Trailer
5.3L V8 Conventional Trailer
5.3L V8 Gooseneck/Fifth-Wheel
Trailer
6.2L V8 Conventional Trailer
SAE J2807 Compliant
Axle Ratio
3.42
3.42
3.42
3.42
3.42
3.73
3.73
3.23
Maximum Trailer
Weight (c)
4 218 kg (9,300 lb)
3 856 kg (8,500 lb)
3 674 kg (8,100 lb)
4 944 kg (10,900 lb)
4 808 kg (10,600 lb)
4 990 kg (11,000 lb)
4 853 kg (10,700 lb)
4 218 kg (9,300 lb)
GCWR (a)
6 804 kg (15,000 lb)
6 804 kg (15,000 lb)
6 804 kg (15,000 lb)
7 575 kg (16,700 lb)
7 575 kg (16,700 lb)
7 575 kg (16,700 lb)
7 575 kg (16,700 lb)
6 804 kg (15,000 lb)