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 V8 engine by Volkswagen Group by customer demand. Renamed the L675, it remains under continuous development, despite an attempt to replace it with the 6.0L W12 Volkswagen engine. The Bentley brand and all former Rolls-Royce and Bentley automotive manufacturing assets have been owned by Volkswagen AG since 1998. "For further detail of the L Series V8 engines developed since the 1950s for use in Rolls-Royce (to 1998) and Bentley (ongoing) automobiles, see Rolls-Royce - Bentley L Series V8 engine" Around 1987, the requirement for a more modern, downsized V8 engine was identified. Engine designers Derek Jackson and Geoff Attwood performed the majority