BMW engineers have run into trouble fitted the M DCT transmission to the F10 M5, according to a report.

BMW may be left no choice but to offer the upcoming 2012 M5 solely with an automatic transmission.

According to a report by Motor Trend, BMW engineers ran into trouble fitting the M Dual Clutch Transmission (M DCT) to the F10 M5. Apparently, the torque is too much for the M DCT to handle with the 4.4 liter twin-turbo V8 dialed up to around the 550 horsepower (410 kW / 558 PS) mark. The configuration's torque rating remains unknown.

M division engineers considered adding larger actuators to the M DCT but that would slow the gearbox's response time. Only a complete revision of the M DCT would do and that appears to be too big a challenge, in terms of work required and costs, for BMW.

So, the only alternative left is to fit the F10 M5 with the ZF 8-speed automatic (sequential with paddle-shifters) gearbox and leave the M5 as an automatic-only just like the X5 M and X6 M models. Of course, the M5 is in a class of its own being one of the core M division models.

It will definitely pain M enthusiasts to know that there will be no proper manual gearbox available.