It's not really fair to call the M140i the elephant in the room because, next to our M135i, it looks so ridiculously slender. Actually, to my eyes, it looks brilliant, with the car brought to bear here - an immaculate 20,000-mile-old, £22,500 example currently on sale at Beck Evans - in arguably the perfect Q car spec. It doesn't half leave our bigger, more practical M135i looking a bit awkward - although we didn't pay the dealership a visit to talk design. We asked to borrow its straight-six hot-rod to answer a question that's hung over our long-termer since it arrived back in March.
Is the new M135i xDrive really worthy of that badge? M-tweaked models aren't supposed to be out and out performance cars like the full-blooded machines - they're supposed to straddle the attainable gap. Nevertheless, we've been less than completely convinced by the all-wheel drive, four-cylinder F40-gen range-topper when it comes to the more spirited stuff; it's won Matt over during a long motorway journey and I'm totally sold on its touring abilities. Comfort mode really does do what it says on the tin. But in the company of its predecessor, it needs to be more than a bit forgiving over speed humps. It needs to be fun.
When it was new, this M140i Shadow Edition would have cost a little over £40k with options. Our M135i xDrive is £43,190 with extras so, accounting for inflation, the generational comparison is on the money. Engine and looks aside, the new machine inevitably has progress on its side. The digital instrument cluster and high-def infotainment screen, complete with its standard Apple CarPlay, walks all over the old car's dials and dated central screen. Same goes for functionality; it's easy enough in the M140i, but the new BMW menus have been made quicker to navigate.
I'm not saying the new cabin is more pleasing on the eye, though, because the M140i's all-black, leather-clad cabin still looks the part. The part-analogue dials and the seats are just lovely. Our M135i's harder cushioned, cloth alternatives are more supportive, but the M140i's - conceivably aided by a couple of years of use - are softer and more cosseting. The freshly treated leather of this car is very pleasant on the nostrils, too.
There's also no getting away from the fact that the old 1 Series platform places you lower in the structure, with your legs ahead and arms easily placed on the wheel. You're perched noticeably more upright in the new car. That's deliberate, of course, and a direct result of the latest platform being asked to do more jobs - not least compete with the VW Golf. With it you get lots more cabin room and boot space than the old car, but also the slightly curious profile that remains divisive a year into the F40-gen's life.
The M140i continues setting the right tone when you press the start button. Two extra cylinders will do that. The 3.0-litre unit settles into a low-volume idle in the M140i, but you're only ever a small press of accelerator away from its silky-smooth response, with none of the try-hard exhaust noises that accompany this engine in its other applications. Warmed up, it remains absolutely lovely, smooth in its power delivery and accruing excitement the closer it gets to 5,500rpm. 340hp is 340hp, so once spinning, the M140i really shifts. It's also perfectly happy to trundle along under 2,000rpm, thanks to 369lb ft of torque. It's almost effortless.
Certainly, it's a different world when driven back to back with the smaller, more tightly wound M135i engine. The 2.0-litre actually seems more eager in its Sport mode, probably thanks to a quicker responding throttle pedal and cleverer eight-speed gearbox. But in any other mode it begs for a downshift if you squeeze the throttle, never tempting you to lug it out from a higher gear as the M140i does. It is also disinclined to let you experiment with chassis balance, especially when measured against the older car's throttle-adjustable mid corner attitude.
That said, on its adaptive dampers (the M140i is passively sprung) the newer, lighter model feels the better controlled car. Despite its taller body, the M135i benefits from quicker steering and the sort of astute damping you need to exploit it. In comparison it makes the M140i seem slower to respond and more reliant on its engine to deliver thrills. Where the xDrive car will accept hustling to virtually any degree you like, the older car would prefer you move smoothly between seven and eight tenths. The difference is that quite often it seems more satisfying doing the latter, than rushing to find the former.
This variance could be best summed up, however predictable it sounds, as character: the six-cylinder endowed with more, the four-cylinder, less. The M135i is quicker, better sorted and built to succeed where its predecessor arguably failed. Returning from the shoot, it reminded me of all the other ways BMW has hit the nail on the head. But try as it might, it is not a memorable or standout prospect. The M140i, as it slips from what could be called its heyday, is becoming increasingly noteworthy. Partly, of course, because it so obviously doesn't conform to the 2020 hot hatch playbook, but also for the simple fact that it lives long in the memory after you've finished driving it. And for better or worse, that ought to be the distinguishing mark of any car graced with the letter M.
Car: 2019 BMW M135i xDrive
Run by: Matt
On fleet since: March 2020
Mileage: 8,052 (delivered on 3,060)
List price new: £36,430 (price as standard; price as tested £43,190 comprised of Melbourne Red paint for £560, Comfort Pack 2 (steering wheel heating, Powered bootlid operation, Comfort Access, Electric front seats and driver memory) for £1,500, Technology Pack 1 (BMW Icon Adaptive LED Headlights, High-beam Assistant, Parking Assistant, Head-up display, Enhanced Bluetooth with wireless charging, Wi-Fi hotspot preparation) for £1,500, Adaptive suspension for £500, Panoramic glass sunroof for £1,000, Sun protection glass for £300, Through-loading system for £150, Lumbar support, driver and front passenger for £150, Driving Assistant for £1,000, Harmon/Kardon loudspeaker system for £750).
Last month at a glance: Our M135i faces its predecessor head on
Image credit | Ben Lowden
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