The M series was produced only in one cubic capacity – 1994 cc (2.0 L), and was a 16 valve development of the older British Leyland O-series unit first seen in 1978.
The M series uses the same cylinder block as the O-series unit as found in the Maestro and Montego, which mates with the Powertrain Ltd PG-1 manual gearbox.
Tickford also tuned the M-series engine which was installed in 536 models of the Rover 820 in 1991.
It needed to have its power capped: it is believed that Rover's marketing department had a say in the final power output of the M16 Turbo: The request from marketing was to not hinder V6 sales therefore the performance should not exceed that of the 2.7-litre Honda V6 (177PS), hence the performance was limited to 180 PS deliberately.
[citation needed] In the end, 563 examples were built, of which, many ended up in the hands of BAe executives (BAe/Rover company cars being the biggest source of UK Rover 800 registrations at the time).