The M135i is built on the 1 Series’ Leipzig production line, not by the M division in Munich. But the same has been true of every important M car since the E39 M5. So that, in itself, isn’t any black mark necessarily.
The car’s powertrain and suspension can be described as ‘special’. Perhaps not as special as was the case in a full-fat 1 Series M Coupé, but this is a halfway-house solution, and a more affordable and less ‘trick’ machine altogether.
The bonnet hides an engine that has a smattering of novelty and intrigue about it. It produces 315bhp and 332lb ft of torque. The latter should make it pull 10 percent harder through the middle of the rev range than the 135i M Sport coupé, as well as being some £2000 cheaper.
The chassis, however, is a little more similar to that which you might find on a lesser 1 Series. BMW describes it as "M Sport suspension", which suggests that it’s not much different from that of a 125i M Sport, for example. There’s an aluminium-rich MacPherson strut suspension set-up at the front and an independent multi-link rear end, all supported by model-specific springs and dampers. Adaptive dampers are on offer as an option. Passive variable-ratio power steering is standard.
This is the only 1 Series currently on sale with rear wheels and tyres that are wider than those at the front. It’s to transmit the fat portion of torque to the road by the driven rear wheels, you suspect. But it has no mechanical locking rear differential, which in our view is a black mark against the name of anything with an M badge.