The Mazda K-series automobile engine is a short stroke 60° 24-valve V6 with belt-driven DOHC and all-aluminium construction.

The K-series also features a highly rigid aluminum split-crankcase engine block design with 4-bolt mains with additional bolts securing the lower block, an internally balanced forged steel crankshaft with lightweight powder forged carbon steel connecting rods.

Another variant, the KL-DE (also known as the KL-03 outside the US, and fitted to 2.5-litre Ford Probes) was the worldwide version, with 164–174 bhp (122–130 kW; 166–176 PS) in various applications.

It featured solid lifters, a cast crankshaft to reduce rotating mass and a reworked intake system.

A series of two butterfly valves coupled with electronically controlled actuators varied the volume and length of a resonant chamber within the intake manifold.

The valve operates to create three specific first-order resonant frequencies that increase cylinder air charge.