A straight-four engine is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft.
Diagram of a DOHC straight-four engine
1989-2006 Ford I4 DOHC engine with the cylinder head removed
2006-2009 Nissan M9R diesel engine
1908–1941 Ford Model T engine
The Citroën DS is a front mid-engined, front-wheel drive executive car manufactured and marketed by Citroën from 1955 to 1975, in fastback/sedan, wagon/estate, and convertible body configurations, across three series of one generation.
Turn indicators were mounted in the upper corners of the rear window, tail and brake lights integrated in chromed rear bumper.
At the 1963 Amsterdam International Autoshow, Citroën presented a DS body as a sculpture, upright like a rocket, on a rotating platform.
DS19 at the 1956 1000 Lakes Rally