An improved Isuzu Pickup comes back in 1991 promising better performance as it brings along with it another engine option. The 1991 model year, however, sees only two Isuzu Pickup trim levels as the middle trim XS was dropped for this year. For 1991, the Isuzu Pickup comes only in two trim levels: the S and the XS. Each of these two trim levels may come in standard bed, long bed, 1 ton long bed or Spacecab (extended cab) body styles and sizes. All of these models may come in either 2WD or 4WD drivelines.

Just as with the previous year's model line-up, most of the Isuzu Pickup models are equipped with either the 2.6 liter 120 hp 4-cylinder engine or the 2.3 liter 96 hp 4-cylinder engine. New for this year, however, is the 3.1 liter V6 engine that produces the same 120 hp of power but provides more torque at 175 lb-ft. And since this new engine is a V6, it also promises a smoother performance and acceleration. The new engine, however, is available only for the standard bed four-wheel drive models. Standard transmission is still the 5-speed manual gearbox while some models use the 4-speed automatic. Interior comfort and conveniences are once again limited only to the LS trim. Standard features like the tachometer and cassette player and optional features like cruise control, sunroof, and power windows and door locks are available only for the LS trim, just as it was in the previous year. The only standard feature common for all trims is the antilock brakes.