The BMW M30 is a SOHC straight-six petrol engine which was produced from 1968 to 1995. With a production run of 27 years, it is BMW's longest produced engine and was used in many car models. The first models to use the M30 engine were the BMW 2500 and 2800 sedans. The initial M30 models were produced in displacements of 2.5 litres (2,494 cc) and 2.8 litres (2,788 cc). Larger displacement versions were introduced over time, with the largest version being 3,430 cc (209.3 cu in), which was sometimes badged as "3.5 litres". As per the BMW M10 four-cylinder engine from which the M30 was developed, the M30 has an iron block, an aluminium head and an overhead camshaft with two valves per cylinder.