Let's get one thing straight, the new BMW M135i is not attempting to directly replace the silky old 40i. It's a clear departure from that lineage, swapping an inline-six and rear-drive for the conventional-for-2019 setup of a turbo four-pot and all-wheel traction. It does not seek to provide the purebred characteristics of its predecessor and BMW makes no bones about that. This now five-door-only model is essentially a never-before produced Bavarian entry to the segment and the reason is simple: market demand. So we'll do our best to leave the rose tinted glasses in their case. Promise.
For its first M-fettled F40 machine, BMW has set the bar really rather high. The objective from the outset was to create the most broadly talented 1 Series yet, so we're told to expect more cabin space and better refinement along with genuinely better real-world performance. It's not simply a copy and paste job from the Mini JCW, either, despite the fact the M135i shares much of its technical makeup with that car, including a twin scroll turbocharged 2.0-litre with 306hp and 332lb ft of torque and the UKL2 architecture that surrounds it. The rest of the Beemer's hardware is different and its character reflects a "completely different focus", according driving dynamics project manager, Bernhard van der Meer.
Not that we need to make excuses for the new M135i, because as far as straight-line performance is concerned, it slots straight in at the sharp end of its field. The new BMW has exactly the same peak power output as the AMG A35, but its maximum torque arrives from just 1,750rpm and hangs on until 4,500rpm, both earlier and for longer than the Merc's. The M135i sprints from 0-62mph in 4.8 seconds (a tenth slower than the AMG), but that wider torque window suggests rolling acceleration should be stronger. The engine is coupled to an eight-speed Steptronic auto with ratios specific to the M135i, which drives through a front-mounted Torsen limited slip differential and xDrive hardware.
Knowing that while its new car may appeal to a larger audience it has effectively lost its USP, BMW has gone aggressive with the M135i's standard specs. The cabin - now much more spacious front and rear thanks to the transversely-mounted engine and raised roofline - is essentially the same one you get in a high-end 3 Series. It comes as standard with a 10.25-inch central display, a digital instrument cluster and soft-touch plastics, while snug sports seats and an M-Sport steering wheel set the tone. You get cruise control, heated seats and electric folding mirrors as standard, but BMW still only offers Apple CarPlay as an option you have to subscribe to.
On the move, the M135i is a remarkably refined place to sit. Our test car is of hero spec, with optional two-stage damping combined with standard-fit 18-inch wheels (you can upgrade to 19s, if you want), so it's genuinely supple on even the roughest of roads. The engine is quiet and the gearbox feels sweetly matched, the powertrain adopting a satisfyingly effortless manner that requires little more than small flexes of the big toe to moderate progress in town. So good is it that on first impression, we suspect it's the best in class at this stuff.
Clicking the Sport button doesn't significantly hinder this form. There's a slight tightening of damping, but presumably thanks to the structure's rigidity (van der Meer said the M135i has more bracing than any other UKL2 car), the ride remains comfortable and it's only when you press on that an improvement in lateral body control becomes evident. Our test route is really quite bumpy, yet the BMW deals with the undulations and compressions while also remaining composed and responsive through the bends, allowing you to explore its limits of grip without fear of a wheel deflecting off a lump in the road or an unexpected slide.
The steering feels almost as fast as a Fiesta ST's, with the rack and pinion setup of fixed ratio (rejoice!), so the front end feels both eager and predictable. There's little feel passed through the thick rim but you're acutely aware of the work that Torsen diff is doing thanks to minuscule tugs and pulls under heavy throttle. Nevertheless, rest assured this is a car with monumental traction, even on a slippery surface and when the ESC is switched off - so in this regard the M135i stands strong against its rivals. Where it edges ahead of the A35 in particular, however, is in the underlying adjustability that it can exploit on the road. We're not talking Audi S4-like throttle adjustability, the torque split is too even for that here, but rather the sort of turn-in adjustability you get when trail-braking in a traditional hot hatch. BMW worked hard on improving pedal feel and the results make for easy access to the car's sweet balance.
Even the four-cylinder engine is exciting to rev out, its flat torque line superseded by a peak power window that lasts from 5,000-6,500rpm, so there's a noticeable kick in thrust up top. The sound is admittedly a little bland - it's typical of a turbo four-pot - and requires a light dosage of 'BMW hum' through the speakers to inject a little more flavour. But the powertrain's wide-reaching muscle, the thuds of upshifts through the Steptronic and excellent traction no matter your steering angle, mean it is genuinely fun to work hard. Coupled with the good ride, it means this is a car that feels nicely suited to the challenges of a technical British B-road - something van der Meer said is the welcome result of extensive Nurburgring testing.
It's hard to find fault with BMW's new offering, then, as it does what it says on the tin so well. Amongst the plush hot hatches of this sector, it's at least as quick as the best, just as comfortable and - on first impression, at least - up there with the best to drive. Objectively speaking, it wipes the floor with its predecessor as well, feeling composed and confident on roads that the six-pot car would have begun to unravel on. And since the new car's altered focus is clear from all angles - you can't miss the more upright stance and 20-litre growth in boot size - it's honest in its approach and not trying to overpromise. We suspect there may be a new favourite kid on the block in this segment - a group test to confirm it awaits.
SPECIFICATION - BMW M135I
Engine: 1,998cc, four-cyl petrol turbocharged
Transmission: 8-speed automatic, all-wheel drive
Power (hp): 306@5,000-6,500rpm
Torque (lb ft): 332@1,750-4,500rpm
Top speed: 155mph
Weight: 1,525kg (without driver)