Editing Straight-six engine (section)

===United Kingdom===
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 | image1    = RR40 50SG.jpg
 | alt1      = Colored dice with white background
 | caption1  = [[Rolls-Royce Silver Ghost]] flathead engine
 | image2    = 1969 Jaguar XJ6 engine.JPG
 | caption2  = 1969 [[Jaguar XK engine|Jaguar XK]] [[Overhead camshaft engine#Double overhead camshaft (DOHC)|DOHC]] engine
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Rolls-Royce's first straight-six engine was a 6.0&nbsp;L [[IOE engine|IOE]] petrol engine, which was used in the 1905 [[Rolls-Royce 30 hp]] luxury car. This car was replaced by the 1906–1926 [[Rolls-Royce Silver Ghost]], which switched to a flathead (side-valve) design for its straight-six engine.

In 1906, the ''[[Standard Motor Company|Standard]] Six'' luxury car was introduced, powered by a {{convert|20|hp|kW PS|0|abbr=on}} I6 petrol engine.<ref>{{cite web |title=Standard |url= https://www.ukcar.com/history/Standard/index.html |website=ukcar.com |access-date=8 October 2022}}</ref> Standard's engines were also used in several cars built by SS Cars and its successor Jaguar, such as the 1932 [[SS 1]] sports car, the 1936 [[SS Jaguar 100]] and the 1938 [[Jaguar Mark IV#SS Jaguar and Jaguar 3½ Litre|Jaguar 3½ Litre]] sports saloon/coupe and the 1948 [[Jaguar Mark V]] luxury car.

The 1927 [[Rover Two-litre]] luxury car introduced the company's [[IOE engine|IOE]] straight-six petrol engine. This engine was used in various Rover models until the [[Rover P5]] was discontinued in 1973, and in various Land Rover models from the 1961 [[Land Rover series#Series IIA|Land Rover Series IIA]] until 1980{{citation needed|date=October 2022}} [[Land Rover series#Series III|Land Rover Series III]].

The 1928 [[Austin Twenty#20/6 Six-cylinder engine|Austin 20/6]] luxury car introduced Austin's flathead straight-six petrol engine. The 1938-1939 Austin Twenty-Eight used an enlarged version of this engine. This was replaced by the [[Austin D-Series engine]], an overhead valve engine initially designed for trucks, which was used in passenger cars from 1947 until 1968 (along with several [[Jensen Motors]] models from 1946 to 1962). The overhead valve [[BMC C-Series engine|BMC C-Series]] was used by various BMC brands from 1954 to 1971, followed by the 2.2&nbsp;L version of the [[BMC E-series engine#2.2-litre engines|BMC E-Series]] overhead camshaft engine, which was produced from 1970 until 1982.<ref>{{cite book |last=Daniels |first=Jeff |date=1980 |title=British Leyland, the truth about the cars |publisher=Osprey |isbn=9780850453928}}</ref>

The 1930–1936 [[Wolseley Hornet six]] lightweight car was powered by a 1.3-1.6&nbsp;L overhead camshaft straight-six petrol engine.

The 1931–1932 [[MG F-type]] tourers, 1932–1934 [[MG K-type]] sports cars, and 1934–1936 [[MG N-type]] sports cars were powered by an overhead camshaft straight-six petrol engine.

During the mid-1930s, the [[Riley MPH]] sports car and ''Riley Kestrel 6''<ref>{{cite web |title=1934 Riley Kestrel 6 Cylinder S/S |url= https://ashridgeautomobiles.co.uk/sales/1934-riley-kestrel-6-cylinder-s-s/ |website=Ashridge Automobiles |access-date=9 October 2022}}</ref> saloon were produced in small numbers and were powered by dual overhead camshaft straight-six petrol engine.

The 1947 [[Bristol 400]] luxury car was powered by an overhead valve straight-six petrol engine based on the design of the [[BMW M328]] engine. This engine remained in use until the [[Bristol 406]] was discontinued in 1961.

The dual overhead camshaft [[Jaguar XK6 engine]] petrol engine was produced from 1948 to 1992 in the [[Jaguar XK120]] sports car. Introduced as a 3.4&nbsp;L, it was used in passenger and racing cars, produced in displacements of 2.4 to 4.2&nbsp;L. The XK6 engine was followed by the [[Jaguar AJ6 engine|AJ6 and AJ16]] engines, produced from 1984 to 1996, before being replaced by a Ford-derived V6 engine.

The 1948–1959 [[Lagonda straight-6 engine|Lagonda straight-6]] dual overhead camshaft petrol engine was used in various Aston Martin and Lagonda cars. This engine's successor was the Tadek Marek-designed straight-six used in the DB4 (1958), DB5 (1963), DB6 (1965) and DBS (1967).

The [[Ford Zephyr engine#Zephyr 6|Ford Zephyr 6]] overhead valve engine was used in the ''Ford Zephyr'' executive car and several other models from 1951 to 1966.

The [[Triumph I6]] overhead valve straight-six petrol engine was produced from 1960 to 1977 and debuted in the Standard Vanguard Six sports saloon. The [[Leyland PE166 engine|Leyland PE166]] engine was loosely based on the Triumph design and was produced from 1977 to 1986.

The 1972–1977 [[TVR M series#2500M|TVR 2500M]] sports car was powered by the Triumph I6 engine. Then, from 1999 to 2007, TVR's own [[TVR Speed Six engine|TVR Speed Six]] dual overhead camshaft engine was used in several of the company's sports cars.