The top-end Rover 90 appeared with a much larger more powerful inline-six at the same time, 24 September 1953 as the four-cylinder Rover 60 was introduced. Rover's idiosyncratic central gear change lever designed to allow three-abreast seating in front was used for this new car. This engine produced 90 hp (67 kW) and could propel the car to reach 90 mph (145 km/h). It has a cast-iron block with an aluminium alloy head, a bore and stroke of by and a 6.73:1 compression ratio. This was upped to 7.5:1 in 1956.