The British Triumph Motor Company produced the Stag model from 1970 to 1978, and it was plagued by engine issues pretty much from the start. This was due to “the need to fit low compression pistons to comply with California’s low octane petrol requirements and the associated advance in ignition timing to meet the USA’s continually changing emission regulations.

The result was that the engine developed greater heat and, when automatic transmission and air conditioning were fitted, the engine cooling ability was overly compromised. Although USA cars were fitted with engine cowls to try to compensate, all too often the result of a freeway tailback was an overheating engine.”