The UK auto industry built 106,398 engines in August, down 35.1% year on year.
Production for domestic and overseas markets declined 36.9% to 38,063 and 34.1% (68,335) respectively.
Year to date output was off 35.2% 1,097,732.
Mike Hawes, SMMT chief executive, said: “These figures come at an extremely worrying time for the sector as it braces for a second wave of coronavirus. Further restrictions both here and in important export destinations will dent consumer and business confidence and inject yet more uncertainty into an already fragile market.”