The Benz Bz.IV was a German six-cylinder, water-cooled, inline engine developed for aircraft use.

The Bz.IV was a dual-camshaft design, with two intake and two exhaust valves per cylinder.

The cylinders were cast iron surrounded by a sheet metal cooling jacket.

A high compression version of the engine (Bz IVü) was produced from 1917 onwards and can be recognised by the red bands painted on each cylinder.

In February 1918, pistons from a Bz.IV were the first captured aluminium pistons to be examined by the British Ministry of Munitions.