What is it?
The new BMW 1-series coupé is a hugely significant car. Forget the paltry projected sales figures (BMW GB expects to sell no more than 3600 a year of all variants), and forget the, er, challenging visual detailing. In fact, you can even forget about the mouthwateringly powerful 135i that we drove last week.
Why? Because I would bet several of my limbs that history will record the 1-series coupé as important for one reason. And that reason is the 123d or, more specifically, the 201bhp twin-turbo turbodiesel under the bonnet.
If that sounds like so much hyperbole, then consider a few key facts. This is the most powerful four-pot turbodiesel you can buy, as well as being the first one on sale equipped with twin turbos (not a twin-scroll turbo).
But the killer point is that all this comes coupled with serious green credentials. So you get 295lb ft, 0-62mph in 7.0sec and a 148mph top speed at the same time as 54.7mpg and 138g/km of CO2. That’s the same CO2 output as a Skoda Roomster diesel.
What’s it like?
The 123d’s performance on the road is equally impressive, with a smooth, linear power delivery providing decent shove from 1800rpm right up to 4500rpm. It’s pretty refined, too, though not as sonorous as a BMW or Audi six-cylinder diesel.
For rest of the car, the praise is a little less gushing. As with the 135i, the 123d is a neat and tidy handler, with an ultimate tendency to understeer.
But unlike in the 135i, the steering is electrically assisted and, while accurate, it seems oddly detached, almost like an arcade game with fake force feedback.
The interior is impressive enough, with plenty of space and great-quality materials, particularly the Boston Red leather of our test car – an £965 option.
Which brings us to the one major weakness of the 123d – price. In M Sport guise you’ll be forking out £26,290 before options. That’s over three grand more than the equivalent Audi A3.