2015 GMC Sierra 2500HD IV (GMTK2XX) Regular Cab Long Box Dimensions, Size & Specs

The GMC Sierra 2500HD IV Regular Cab Long Box offers a generous luggage capacity of approximately 2160 to 2162 liters (about 76.3 to 76.4 cubic feet) with the rear seats folded. Given this is a Regular Cab Long Box configuration, the bed itself is long and ideal for carrying large and heavy loads, making it well-suited for heavy-duty tasks such as construction, hauling tools, materials, and other equipment.

This generation of the GMC Sierra 2500HD Regular Cab Long Box has a curb weight ranging between 2604 kg to 2993 kg (about 5739 to 6599 pounds). The maximum gross vehicle weight rating (GVWR), which includes the vehicle, passengers, cargo, and trailer tongue weight, ranges between 4218 kg to 4536 kg (9300 to 10,000 pounds). This weight capacity ensures the truck is capable of heavy-duty towing and hauling, making it a robust choice for demanding work environments.

The GMC Sierra 2500HD IV Regular Cab Long Box features a ground clearance (ride height) of 231 mm (approximately 9.1 inches). This generous ground clearance improves the vehicle’s ability to navigate uneven terrains, obstacles, and off-road conditions without damaging the undercarriage. It provides an advantage for users who require a pickup truck capable of off-road work or travel on rugged construction sites and rural environments.

The truck, with a height of around 1975 mm (77.8 inches) and width including mirrors of 2035 mm (80.1 inches), could be a tight fit for many standard residential garages, which commonly have door widths of approximately 2440 mm (96 inches) and interior heights of around 2130 mm (84 inches). While the height is generally suitable, the width with mirrors opened may require mirror folding or careful maneuvering. Therefore, it fits in many garages but might be challenging in smaller or custom garages without adequate space.

Compared to the previous GMC Sierra 2500HD generation, the fourth-generation (GMTK2XX) Regular Cab Long Box maintains very similar overall length and height dimensions, with slight refinements in styling and structure that impact aerodynamics and interior space. The curb weight generally increased slightly due to upgraded materials and technology integration, supporting increased towing and payload capacities. Width with mirrors remains comparably wide, sustaining its full-sized and utilitarian nature. Overall, this generation improved fuel efficiency and modernized drivetrain options while retaining the familiar large truck footprint.

Within its class of heavy-duty pickups, the GMC Sierra 2500HD IV Regular Cab Long Box holds competitive exterior dimensions and weight. For example, when compared with the Ford F-250 Super Duty of similar years, the GMC is slightly longer (5699 mm vs. about 5867 mm / 224.3 inches vs. 231 inches for Ford) but similar in height and width. Its curb weight is also within the competitive range, offering robust towing and hauling capabilities. This makes the Sierra 2500HD a strong contender in the segment, balancing bulk with utility.

The truck comes with multiple rim sizes including 7.5J x 17, 8J x 17, 8J x 18, 8.5J x 20, and 8J x 20 inches, paired with tire sizes such as 245/75 R17, 265/70 R17, 265/70 R18, 265/60 R20, and 235/80 R17. The variety of tire and rim configurations allows for adjustment depending on use case—larger rims and lower profile tires improve road handling and aesthetics, while smaller rims with higher profile tires provide better cushioning and off-road durability. This versatility lets owners tailor fitment for highway comfort or rugged terrain performance.

Building on its curb weight of 2604 to 2993 kg (5739 to 6599 pounds) and GVWR up to 4536 kg (10,000 pounds), the GMC Sierra 2500HD IV Regular Cab Long Box is engineered for substantial payload and towing tasks. Payload capacity typically ranges from approximately 1000 kg to 1300 kg (2200 to 2860 pounds), depending on equipment and configuration. Towing capacity varies widely with engine choice and specifications but can reach over 6800 kg (15,000 pounds) for trailers, making this model ideal for heavy-duty commercial and personal hauling needs.

The Regular Cab Long Box of the 2015-2019 GMC Sierra 2500HD IV configuration focuses primarily on utility with limited passenger capacity. Featuring a single row of seating, it typically accommodates two to three occupants, offering straightforward functional interior space optimized for work purposes. While lacking rear passenger cabins, its interior incorporates durable materials and ergonomically placed controls to improve driver comfort. Compared to extended cabs or crew cabs, it sacrifices passenger volume but gains in longer cargo bed length and generally lower weight.