Rolls-Royce Merlin exhaust flow and waste-gates, meant that this option was rejected in favour of the two-stage supercharger. Fitted with the two-stage two-speed supercharger, the Merlin 60 series gained 300 horsepower (224 kW) at over the Merlin 45 series, at which altitude a Spitfire IX was nearly faster than a Spitfire V. The two-stage Merlin family was extended in 1943 with the Merlin 66 which had its supercharger geared for increased power ratings at low altitudes, and the Merlin 70 series that were designed to deliver increased power at high altitudes. While the design of the two-stage supercharger forged ahead, Rolls-Royce also
Rolls-Royce–Bentley L-series V8 engine the VAG W-12 engine. Rolls-Royce–Bentley L-series V8 engine The Rolls-Royce–Bentley L-series V8 engine was introduced in 1959 and is still in production. Built in Crewe, it was used on most Rolls-Royce and Bentley automobiles in the four decades after its introduction and is still used in the Bentley Mulsanne. With BMW's acquisition of the rights to use the Rolls Royce name in 1998, Rolls-Royce Motor Cars began using BMW supplied V12 engines but Bentley Motors Limited under Volkswagen ownership continued to use highly modified versions of the L series on its Arnage, Brooklands and Mulsanne models, with VAG W-12 engines