Cummins L9

The number in the name is the output in hp; suffixes such as EV, H or HS denote torque curves and calibrations. The register lists 23 versions with 260 to 450 hp at 1,900 to 2,200 rpm and 860 to 1,250 lb-ft (1,166 to 1,695 Nm) of torque between 1,200 and 1,400 rpm; all with 8,900 cm³, direct injection and turbocharging, certified for model years 2017 to 2026, predominantly for bodied trucks ('Vocational').

Compared with the ISL9, torque at the top end rose to 1,250 lb-ft and the torque speed fell to 1,200 rpm – Cummins' response to automated transmissions and the demand for low revs in city traffic.

On used engines in refuse and city-bus duty, the regeneration cycles of the particulate filter and the condition of the SCR dosing are the checkpoints; the variable-geometry turbocharger and the EGR cooler are the typical wear parts of this engine class.