Editing Diesel engine (section)

===Commercial vehicles and lorries===
{{Image frame|width=220|content=
{{Graph:Chart|width=150|height=200|xAxisTitle=Engine model|yAxisTitle=Lifespan (km)|yAxisFormat=s|type=rect |yGrid= |xAxisAngle=-40
|x=OM 355,OM 400, OM 500, OM 470|y=500000,750000,1000000,1200000}}
|caption=Lifespan of Mercedes-Benz diesel engines<ref name="Merker_2014_264" />|link=|align=right}}

In 1893, Rudolf Diesel suggested that the diesel engine could possibly power "wagons" (lorries).<ref name="Diesel_1893_91" /> The first lorries with diesel engines were brought to market in 1924.<ref name="Tschöke_2018_10" />

Modern diesel engines for lorries have to be both extremely reliable and very fuel efficient. Common-rail direct injection, turbocharging and four valves per cylinder are standard. Displacements range from 4.5 to 15.5 litres, with [[Power-to-weight ratio|power-to-mass ratios]] of 2.5–3.5&nbsp;kg·kW<sup>−1</sup> for heavy duty and 2.0–3.0&nbsp;kg·kW<sup>−1</sup> for medium duty engines. [[V engine|V6 and V8 engines]] used to be common, due to the relatively low engine mass the V configuration provides. Recently, the V configuration has been abandoned in favour of straight engines. These engines are usually straight-6 for heavy and medium duties and straight-4 for medium duty. Their [[undersquare]] design causes lower overall piston speeds which results in increased lifespan of up to {{convert| 1200000| km|mi}}.<ref name="Merker_2014_48" /> Compared with 1970s diesel engines, the expected lifespan of modern lorry diesel engines has more than doubled.<ref name="Merker_2014_264" />