Bristol 406 1958-1961

The Bristol 406 was a luxury car produced between 1958 and 1961 by British manufacturer Bristol Aeroplane Co. (whose car division would later become Bristol Cars). It was the last Bristol to use the BMW-derived pushrod straight six engine that had powered all cars built by the company up to that point but was clearly inadequate to give the car performance comparable to that of newer engines emerging at the time.

According to the official history of Bristol Cars, the company was working on a new six cylinder engine during the period when the 406 was in production. Only when Bristol found any new six cylinder engine it could develop would still be unable to compete with newer engines of larger size, did they decide to import V8 engines from Chrysler.

Compared to the 405, the 406 saw several significant changes. The most important was that the six cylinder engine itself was enlarged slightly in both bore and stroke to dimensions of 69 mm by 100 mm (2.71 inches by 3.94 inches). This gave an engine displacement of 2216 cc (135 cubic inches) but the actual power of the engine was no greater than that of the 405.

However, the torque was higher than that of the smaller engine, especially at low engine speeds. The 406 also featured Dunlop-built disc brakes on all four wheels and a two-door saloon body that Bristol were to stick with for a long period after adopting Chrysler V8 engines with the 407. The styling made the 406 more of a luxury car than a true sports saloon.

The rear suspension of the 406 also did away with the outdated A-bracket of all previous Bristols for a more modern Watt's linkage. However, the outdated front suspension of previous Bristols was retained and not updated until the following model with its more powerful drivetrain.