The Isuzu Trooper is a full-size SUV that was produced by the Japanese automaker Isuzu between 1981 and 2007. In the domestic Japanese market it was sold as the Isuzu Bighorn, the car was exported internationally mainly as a Trooper but it also received several other nameplates including Acura SLX, Chevrolet Trooper, Subaru Bighorn, SsangYong Korando Family, Honda Horizon, Opel Monterey, Vauxhall Monterey, Holden Jackaroo, and Holden Monterey. In total, there were two generations of this vehicle: the first, produced between 1981 and 1991; and the second (UBS) produced between 1991 and 2007, with a substantial refresh in 1998. Production ended in 2007. The Trooper began as a rather basic and somewhat underpowered on- and off-road vehicle, offered only with four-cylinder motor, four-speed manual transmission, and part-time four-wheel drive. The first generation evolved to add both amenities and luxuries, including optional air-conditioning, power windows, and a more powerful V6 engine. The second generation was even more refined and available in two-wheel drive as well as four-wheel drive. First generation (1981–1991) The first-generation Trooper was available as a three-door wagon or a soft top with independent front suspension. The soft-top model sold slowly and did not last long. In the Japanese market, the car was originally introduced as the "Isuzu Rodeo Bighorn", but the "Rodeo" part of the name was soon dropped. Early engines included a 1.95-liter gasoline and a 2.2-liter diesel, lightly powered even by early-1980s standards for the vehicle's empty weight. The four-wheel-drive system was engaged by operating a three-position shifter adjacent to the transmission shifter. Both Aisin manual-locking and Isuzu's own auto-locking hubs were employed. In 1986, Isuzu introduced the five-door version and the 4ZD1 four-cylinder engine 2.3-liter petrol engine. Apart from higher power, changes to the previous engine included a Kevlar timing belt replacing the previous chain, and a larger two-barrel carburetor. This engine eventually proved somewhat problematic with a high incidence of burned valves due to poor coolant-flow design of the overhead cam/valve head with mechanical lifters. A later head casting improvement by an Italian firm corrected this problem through improved coolant flow. Also available only for 1986 in the US was the 2.2-liter C223T turbocharged diesel engine, using a Garrett turbocharger. It was not a popular option because of the low power generated, and furthermore is notorious for a weak bottom end, the connecting rods not originally designed for the increased thermal and mechanical stress