1989 GMC Sierra 1500 I (GMT400) Regular cab SWB Wideside Dimensions, Size & Specs

The maximum weight of the 1989 GMC Sierra 1500 I Regular cab SWB Wideside is 2540 kg (5597 lbs). This maximum weight includes the vehicle's curb weight plus payload capacity. The combination of durable chassis engineering and its robust suspension allows it to handle heavy-duty workloads while maintaining stable handling characteristics. This weight capacity is typical for pickup trucks in its class during the late 1980s and early 1990s, making it suitable for both commercial applications as well as personal use.

The 1989 GMC Sierra 1500 I Regular cab SWB Wideside is equipped with tire sizes 225/75 R15 or 225/75 R16. Both tire sizes provide a balance of ground clearance, road grip, and ride comfort, well-matched to the truck’s dimensions and weight. The aspect ratio and width offer good sidewall height to absorb shocks from uneven terrain, a common requirement for pickup trucks that serve both on-road and off-road purposes. These tires are conventional sizes that remain common among similar pickup models.

The dimensions of the 1989 GMC Sierra 1500 I Regular cab SWB Wideside—length 5065 mm (199.4 inches), width 1951 mm (76.8 inches), and height 1788 mm (70.4 inches)—mean it generally fits into a standard single-car garage. Most single-car garages measure approximately 6000 mm (20 feet) in length, 3000 mm (10 feet) in width, and about 2130 mm (7 feet) in height, providing sufficient clearance. However, parking care should be taken due to its width close to typical garage door widths, and any modifications or additional rooftop equipment might affect garage accessibility.

Compared to its predecessor, the 1989 GMC Sierra 1500 I (GMT400) Regular cab SWB Wideside is somewhat larger and more refined in exterior dimensions and load capacity. Previous GMC Sierra models from before the GMT400 series were generally shorter and less wide, as GM moved towards a more aerodynamic and spacious design with the GMT400 platform launched in 1988. The increased length, width, and height in this generation enhances cabin comfort and cargo capacity, while also providing improved safety features and better handling through updated chassis engineering.

The 1989 GMC Sierra 1500 I competes with similar full-size pickups from Ford (F-150) and Dodge (Ram 1500) in size and capability. Its length of 5065 mm (199.4 inches) and width of 1951 mm (76.8 inches) place it squarely in line with competitors, offering comparable cabin space and cargo bed size. Its Wideside bed version was popular for providing a wider, more practical load area compared to traditional step side beds, similar to Ford’s styles of the era. Compared to rivals, the GMC delivered a balanced mix of durability, comfort, and performance with a focus on a rugged yet refined design.

The 1989 GMC Sierra 1500 I Regular cab SWB Wideside, being a regular cab model, is designed primarily for two or three occupants with bench-style seating. The interior focuses on functional ergonomics with ample headroom and legroom for front passengers despite the shorter wheelbase (SWB). The cab dimensions emphasize straightforward utility often favored by work truck users, yet it maintains enough space for long-distance comfort. Its design features durable materials typical of the late 1980s and early 1990s, balanced with basic comfort and instrumentation.

The 1989 GMC Sierra 1500 I Regular cab SWB Wideside features a 'Wideside' cargo bed characterized by wider bed sides compared to the traditional 'Stepside' design. This model's short wheelbase (SWB) enhances maneuverability while the Wideside bed maximizes cargo volume, ideal for hauling larger and wider items. While exact bed dimensions vary slightly, a typical SWB Wideside bed measures approximately 1780–1830 mm (70–72 inches) in length and about 1951 mm (76.8 inches) in width—matching the truck’s overall width—thus providing a roomy and practical platform for most pickup applications.

While specific ground clearance figures for the 1989 GMC Sierra 1500 I Regular cab SWB Wideside are not provided here, typical ground clearance for GMT400 pickups ranges between 180 mm (7 inches) to 220 mm (8.7 inches) depending on suspension and tire size. Paired with tire sizes 225/75 R15 or R16, this truck offers good clearance for moderate off-road use and rugged terrain. Its durable frame, robust suspension, and payload capacity of up to 2540 kg (5597 lbs) make it well-suited for both worksite conditions and recreational off-roading, maintaining solid traction and durability.

The 1989 GMC Sierra 1500 I, part of the GMT400 series, marked a significant evolution in performance and design for GMC pickups. Known for its rugged body-on-frame construction, the Regular cab SWB Wideside variant offered versatile usability with efficient powertrain options, including V6 and V8 engines common to that era. It featured improved aerodynamics over its predecessors and incorporated modern amenities such as improved seating ergonomics, better sound insulation, and updated instrumentation. This generation balanced workhorse durability with daily driving comfort, making it popular among both commercial users and private owners.