Isuzu AP-4LE2X

The register lists here 40 versions with 26 to 397 kW rated output at 1,800 to 2,400 rpm, from four- to six-cylinders with 85 to 147 mm bore and 96 to 154 mm stroke, torques from 136 to 2,250 Nm at speeds of 1,350 to 1,800 rpm. Of 35 engines with a documented turbocharger, variable-geometry design prevails (20) ahead of fixed geometry (10) and waste-gate (5); injection is direct on 34 of the 40 engines, indirect on 6. Among the emission stages, Tier 4 (Final or Phase-in) leads with 19 ahead of Interim Tier 4 with 18 and Tier 3 with 3 versions.

The engines cover the mid to upper power segment for construction machinery, forklifts and stationary applications; the long span of model years shows how durable individual Isuzu certifications remain on the market, with little change to the technical version.

On a used purchase, operating hours count, the condition of the turbocharger depending on type, the injection pump or, on the direct-injection engines, the injectors, the tightness of crankshaft seals and charge-air ducting, and on the newer Tier 4 Final engines the exhaust aftertreatment; since individual certifications run unchanged over many model years, it is worth checking the exact model year against the nameplate. Spares run through the Isuzu dealer network.