Engine output decreased 4.2% in May, with a 1.1% fall over 2014-to-date, according to the Society of Motor Manufacturers (SMMT). Exports continued to grow and accounted for over 65% of year-to-date output.
SMMT said: "With new production facilities gearing up for launch and a growing European market, the future is positive for the UK's engine manufacturing industry."
Meanwhile, commercial vehicle output fell 32.2% in May, as restructuring impacts continued.
Manufacturing was down 22.8% over the year-to-date, with output for both home and export down. Production is expected to stabilise soon.
Mike Hawes, SMMT chief executive, said: "UK commercial vehicle output continued to feel the effects of last year's production restructuring with volumes down 32% in May. There is light at the end of the tunnel, however, as we look forward to the end of this impact in late summer.
"The next few months will also see new models rolling off UK assembly lines, which will help boost production numbers."