1987-1991 Isuzu Trooper Soft Top 2.3 (UBS16) (90 Hp)

The Isuzu Trooper Soft Top 2.3 (UBS16), produced between 1987 and 1991, represents a unique and relatively uncommon variant within the first generation of Isuzu’s popular SUV. This model, characterized by its removable soft top and 2.3-liter gasoline engine producing 90 horsepower, was primarily aimed at recreational buyers seeking an affordable and open-air off-road experience. It occupied the entry-level position in the Trooper lineup, offering a more accessible price point compared to the hardtop models and those equipped with larger engines. The UBS16 chassis code designates this specific configuration, distinguishing it from other Trooper variants available during its production run. The Trooper, known as the Bighorn in some markets, was Isuzu’s attempt to compete in the rapidly growing SUV segment, offering a blend of off-road capability and on-road comfort.

Technical Specifications

Powertrain & Engine Architecture

The heart of the Trooper Soft Top 2.3 is Isuzu’s 2.3-liter, naturally aspirated four-cylinder gasoline engine. While specific engine codes varied slightly depending on the market, the UBS16 typically utilized a SOHC (Single Overhead Cam) 16-valve configuration. This engine, though not particularly powerful by modern standards, was known for its relative simplicity and durability. Fuel delivery was managed by a carburetor in earlier models, transitioning to multi-point fuel injection in later years of production, improving efficiency and responsiveness. The engine’s longitudinal mounting allowed for a traditional front-engine, rear-wheel-drive layout, with four-wheel drive available as an option or standard depending on the trim level. The automatic transmission paired with this engine was typically a four-speed unit, chosen for its ease of use and suitability for recreational driving. This transmission wasn’t known for its sporty performance, prioritizing smooth shifts and reliability over rapid acceleration.

Driving Characteristics

The 90 horsepower output of the 2.3-liter engine, coupled with the four-speed automatic transmission, resulted in driving characteristics best described as adequate. Acceleration was leisurely, particularly when fully loaded or tackling steep inclines. The automatic transmission’s gear ratios were geared towards fuel economy and low-end torque, rather than outright speed. Compared to the available 2.6-liter and later 3.1-liter engines offered in other Trooper models, the 2.3 felt noticeably underpowered. Manual transmission versions of the 2.3 offered a more engaging driving experience, allowing the driver to better utilize the engine’s limited power band. However, the automatic version appealed to buyers prioritizing convenience and ease of driving, especially those new to SUVs or off-road vehicles. Off-road, the Trooper Soft Top 2.3 proved surprisingly capable, thanks to its four-wheel-drive system and relatively short wheelbase. The soft top, while offering an open-air experience, did contribute to some chassis flex over rough terrain.

Equipment & Trim Levels

The Trooper Soft Top 2.3 typically represented the base trim level. Standard equipment generally included basic cloth upholstery, a simple dashboard layout with analog gauges, and manual windows and locks. Air conditioning was often an optional extra, as were features like a rear wiper and upgraded audio systems. The soft top itself was usually made of durable vinyl or canvas material, with a folding mechanism that allowed for relatively easy removal and storage. Interior appointments were functional rather than luxurious, reflecting the vehicle’s affordable price point. The focus was on providing a practical and durable interior that could withstand the rigors of off-road use. Optional extras often included upgraded wheels, exterior trim enhancements, and a tow package for those looking to utilize the Trooper for light towing duties.

Chassis & Braking

The Trooper Soft Top 2.3 utilized a body-on-frame construction, common for SUVs of that era. The suspension consisted of independent front suspension with coil springs and a live rear axle with leaf springs. This setup provided a reasonable balance between ride comfort and off-road capability. Braking systems varied depending on the market, but typically included front disc brakes and rear drum brakes. Power steering was often standard, making maneuvering the Trooper easier, especially at low speeds. Stabilizer bars were typically fitted to the front axle to reduce body roll during cornering. The chassis was designed to handle the stresses of off-road driving, with reinforced components and a robust frame. The relatively light weight of the 2.3-liter engine and the absence of a hardtop contributed to a slightly lower center of gravity compared to heavier Trooper variants.

Market Reception & Comparison

The Isuzu Trooper Soft Top 2.3 received mixed reviews from automotive critics. While praised for its affordability and off-road capability, it was often criticized for its lack of power and relatively basic interior. Compared to competitors like the Suzuki Samurai and early Jeep Cherokee models, the Trooper offered a more comfortable ride and a more spacious interior. However, it lacked the brand recognition and established reputation of some of its rivals. Fuel economy was reasonable for the time, but not exceptional. Reliability was generally good, although the carburetor-equipped models required more frequent maintenance than the fuel-injected versions. The automatic transmission, while convenient, was sometimes criticized for its sluggish performance. The Trooper Soft Top 2.3 appealed to a niche market of buyers seeking an affordable and versatile SUV with an open-air experience.

Legacy

The Isuzu Trooper Soft Top 2.3, while not a high-volume seller, has developed a cult following among off-road enthusiasts and Isuzu aficionados. The simplicity of the 2.3-liter engine and the availability of parts make it a relatively easy vehicle to maintain and repair. The soft top configuration adds a unique appeal, offering a different driving experience compared to the more common hardtop models. In the used car market today, these Troopers are often sought after by collectors and those looking for a classic off-road vehicle. While rust can be a concern, particularly in areas with harsh winters, well-maintained examples can still provide years of reliable service. The UBS16’s legacy lies in its contribution to the Trooper’s overall success and its representation of a simpler, more adventurous era of SUV design.