BMW M140i | PH Used Buying Guide

The fast 1 Series was always appealing, but it was the facelifted F20 that found the sweet spot

By Tony Middlehurst / Sunday, 30 October 2022 / Loading comments

Key considerations

  • Available for £16,000
  • 3.0-litre straight-six petrol turbo, rear-wheel drive
  • Lovely drivetrain, manual or auto
  • Nothing special inside, but usefully practical
  • Strong reliability record
  • Prices seem strangely low for these ‘last of era’ cars   

Followers of football will know that some of the game’s best-ever players have had what experts liked to call a big engine in a compact body. This analogy was pinched from the automotive world. As long as the chassis was up to it, bunging a powerful motor into a small car has generally produced a brilliant result.  

In contemporary Germanic hot hatch lore, three names loom large: Golf R, AMG A45 and Audi S3. All fine cars neatly espousing the principle of high horsepower nailed to the road by all-wheel drive. The Golf R is often quoted as the main rival to the M140i, and it’s an accomplished vehicle to be sure but it’s certainly no more exciting to drive than the BMW, and if you live in any sort of built-up area Rs even more nickable than the M140is. 

Alternatively, looking outside Germany (sort of), you might be tempted by front-drivers like the Seat/Cupra Leon or Civic Type R. If, however, you believed that rear-wheel drive was the one and only route to handling Nirvana and you couldn’t run to a recent enough RWD BMW M3 then the non xDrive BMW M135i was a durned good shout. Based on the F21 three-door and F20 five-door body styles that had been around since 2011, the M135i wasn’t just one of the quickest and most fun ways to get across a country without using motorways, it was also pleasantly affordable (especially on PCP deals) and usefully practical in three- or five-door iterations. 

It was an attractive package that found many buyers, but it wasn’t perfect. Once the initial euphoria had died down, road testers and owners began to find flaws. The electric steering was panned, the suspension was queried and more than a few British owners found the car to be a bit of a handful on crinkly roads in wet weather. 

So there was a crackle of anticipation in the air in 2016 when BMW launched the new and improved M140i, still based on the gen-two F20/21 but with the new ‘Baukasten’ B58 engine that had made its debut shortly before in the F30 340i and 440. Like the M135i’s outgoing N55, the B58 was still a 3.0-litre inline six, but its compression ratio and turbo boost pressure were both higher than those of the old engine. In single twin-scroll turbo M140i guise it dished up around 14hp more than the N55, its 335hp peak arriving at a slightly less frantic 5,500rpm. The 37lb ft torque hike to 369lb ft was more substantial, though you did have to wait slightly longer for it to come on stream – 1,520rpm as opposed to 1,300rpm in the M135i. 

Until around July 2018 when it was deleted from both it and the M240i, the M140i’s default transmission was an excellent 6-speed manual. The ZF 8-speed option was also excellent, plus it chopped 0.2sec off the manual’s 0-62 time (taking it down to 4.6sec) and added more than three miles to every gallon in mixed use. It didn’t come as much of a shock therefore when the overwhelming majority of M140i buyers happily stumped up the £1,430 premium for the auto. Today the split in the used market is around twelve autos for every manual. 

There was an all-wheel drive xDrive version of the M140i. It was between 65kg-70kg heavier than equivalent RWD M140is but that weight penalty didn’t stop it from being even quicker through the 0-62, which it covered in just 4.4sec. Sadly it wasn’t officially sold in the UK so there won’t be many (if any) right-hand drive examples around. 

There was a LCI 2 (Life Cycle Impulse, or refresh for the rest of us) in late 2017 when the new dash and dials from the M240i were brought across to the M140i and there was some graphic-sharpening on the iDrive. Adaptive sport suspension became standard as did adaptive LED headlights. A £35,785 Shadow Edition (known as the Finale in some markets) joined the range with a black grille, black or grey wheels, M Sport brakes with blue calipers, some other cosmetic fripperies and a Harmon Kardon sound system. 

In 2019 the M140i was given the chop in readiness for the arrival of the F40 1 Series UKL platform cars. The name for the F40 replacement turned out to be the M135i (again) but there were some pretty major deviations from what M fans regarded as traditionally correct for this sub-genre. The new car was all-wheel drive (biased towards FWD most of the time), the 302hp/332lb ft engine only had four cylinders, and you could only have it with a five-door body. So if you wanted a new, six-cylinder, rear-driver with a three-door body (an option that continued right up to the end of F20/21 production) a 2019 M140i was your last chance. It was lighter than the 1,600kg F40 M135i and 0.2sec quicker through the 0-62 run. 

It was slightly less economical at 39.8mpg (around 31mpg in the real world) compared to the M135i’s official combined figure of 41.5mpg, but the impression you get from the comments of M140i owners is that they were more than happy with their cars’ fuel consumption figures. Many also enjoyed the lowness of its profile, although some regretted that relative anonymity (from a distance it could be a 116d) and the lack of respect that could generate from other road users. Some justifiably loved its all-round ability but the M140i’s cool efficiency meant that not everyone got out of it with flushed cheeks. 

One PHer described it as the best car they’d ever owned but that they never really gelled with it. Certainly, you might find something like an M3 more engaging, but then again they’re ‘proper M cars’ (M140is being seen as M-lite) and you can’t get a 2016-on M3 for £16,000. That’s what 90-100,000-mile M140is are going for nowadays. £16,000. Not a lot for such a capable machine, especially one that could fairly be described as an ‘end of era’ car. 

Are secondhand M140i prices artificially low? Or do they have secret drawbacks that make today’s prices about right? Let’s have a closer look at what M140i ownership might feel like.  

SPECIFICATION | BMW M140i (2016-19)

Engine: 2,998cc straight six 24v twin-scroll turbocharged
Transmission: 6-speed man or 8-speed auto, rear-wheel drive
Power (hp): 335@5,500rpm
Torque (lb ft): 369@1,520-4,500rpm
0-62mph (secs): 4.8 (4.6 auto)
Top speed (mph): 155
Weight (kg): 1,520
MPG (official combined): 36.2 (40 auto)
CO2 (g/km): 179
Wheels (in): 7.5 x 18 (f), 8 x 18 (r) 
Tyres: 225/40 (f), 245/35 (r)
On sale: 2016 – 2019
Price new: £32,000
Price now: from £16,000

Note for reference: car weight and power data is hard to pin down with absolute certainty. For consistency, we use the same source for all our guides. We hope the data we use is right more often than it’s wrong. Our advice is to treat it as relative rather than definitive.


BMW has always been known as a master of the six-cylinder engine and the one in the M140i did not disappoint. Some say the N55 sounded better than the B58 but they were both superb engines.

Let’s talk power. The M135i was officially rated at 320hp but there was talk of 350hp sightings from standard cars on rolling roads. Similar discrepancies in BMW’s claims of 335hp/369lb ft for the M140i’s B58 have been reported, with 360hp commonly cited for standard cars and even 380hp on the odd printout. It’s not that hard to believe. In twin-turbo S58 form the B58 went on to produce over 500hp in the Competition versions of the X3/4M and M3/4, and it could be cranked up to over 700hp on the stock internals. 

Whatever the truth may be, you were highly unlikely to feel shortchanged by the M140i’s performance or by the smoothness and refinement with which it delivered that performance. On the standard numbers it made something like a Golf GTI or any other popular hot hatch feel like a milk float. A Stage 1 remap with no inlet mods would conservatively take it to 400hp, unconservatively to 450hp. As a midpoint example the £600 Litchfield remap dynoed at 435hp from 3,000-4,000rpm with 425lb ft from around 2,200rpm to nearly 5,000rpm.

Next, gearboxes. The six-speed was a good ‘un, its cause furthered by the inclusion of the M2’s auto-blip function. The eight-speed auto was lovely but could be quite slow to react to a kickdown command from a heavy right boot if you couldn’t be bothered to use the wheel paddles in Sport mode. Reflashes were available to smarten it up. The auto’s Eco Pro mode was a bit weird, forcing the gearbox to change up as early as possible and even disengaging the clutch to create a coasting function.

Reliability wise it’s a strong story for the whole drivetrain. The exhaust valve was prone to rattling, seizing up or failing entirely. BMW usually replaced these under warranty without too much quibbling. Sometimes they upgraded customers to the Performance exhaust which came highly recommended but more mature owners quite liked the reduced banging and popping from the standard pipe. Pre-June 2018 M140is didn’t have the gasoline particulate filter which made it easy to swap the standard exhaust for an aftermarket cat-back item. You could still do a pipe swap on later GPF’ed cars but in that case you’d have to budget for a bit more work on putting out the resultant engine management light.  

Low coolant levels were discovered on some pre-LCI cars. It was rarely clear where the coolant was going as there would be no obvious leaks. The theory gaining the most traction centred on the filler cap allowing fluid to escape. Any loss would be gradual so even the most cursory of visual examinations should allow you to keep on top of it. 

The original equipment oil filter gained a reputation for falling apart so you needed to be sure to stick (at least) to the service schedule. There were no conventional coolant or oil temperature gauges to look at in an M140i: you had to press the BC button on the left-hand stalk to bring up displays on the info panel between the main clocks, or rely on receiving a message from your iDrive. The dipstick was digital too, which not everybody liked. 

Owner experience suggests changing the oil and filter every 12 months or 8,000 miles at minimum. 0W30 or 5W30 is the recommended engine oil, or 5W40 if your engine has been worked on. The first service was at roughly 20,000 miles (depending on your driving style) or two years, whichever came first. A minor service should be obtainable for under £350. A simple oil change and filters will be about £250. If you go down the independent route make sure that they can register the service with BMW or else there’ll be a gap in your history.


For most owners most of the time the standard chassis setup was fine. The damping in the Comfort setting could seem a little too soft, while Sport could feel too hard. Somewhere in between the two would have been good for many but that wasn’t an option. What was an option however was Adaptive M suspension, reasonably priced at £515 and well-liked by most of those who had it. Harder drivers found it less than optimal at higher speeds though. Birds did a B-series kit which received plenty of plaudits. 

As mentioned earlier, you had to be ready to throw in some quick inputs on wet roads, but some owners saw that as a plus point. The standard diff on the M140i was conventionally open, so traction could sometimes be an issue, but in all honesty we’re talking there about the kind of extreme scenarios that only road testers, trackday fanatics and crack addicts were likely to explore. It is certainly true that fitting the M Performance limited slip diff and some better/lower suspension would lift the M140i onto a new and very nice level, the LSD in particular scoring good points for doing away with the ‘M twitch’ that tightened your bum when grip was lost, replacing it with a deliciously controllable slide. Five-door cars also benefit from the fitment of an underbody brace, something that was standard on the three-doors.  

The steering was supposedly improved over the F20 M135i’s but it could be difficult to spot exactly where those improvements were when you were tramping on. That was when the detachment between the wheels under the car and the one in front of you became most obvious. Luckily, at the more sedate speeds which if we’re being honest most of us operate in most of the time, the M140i was a relaxed and relaxing companion, with the immediately available option of eye-widening acceleration in the lower gears. What the M140i very much wasn’t was an edgy Focus RS or a Civic Type R. 

Road noise could get quite high, just as it had been in the M135i. Michelin Pilot Sport 4S tyres were regularly recommended by owners, ideally with a second set of Michelin Alpin-shod wheels for winter. 


Some found the driving position on manual F20 1 Series cars in general to be a bit painful as the clutch pedal was positioned in line with the middle of the seat, requiring you to twist your left leg more than an ideal amount. Another demerit in the M140i was the presence of some quite cheap-looking cabin plastics. Apple CarPlay wasn’t standard. There was an extra 12v socket that many owners never found under the front lip of the glove box. 

One downside of the rear-drive layout was the presence of the transmission tunnel in the rear compartment which made life awkward for a fifth passenger. There wasn’t a vast amount of room in the back but then that was largely down to it not being large. It was a 1 Series after all, not a 7 Series. For a small car, it was perfectly acceptable for both headspace and general comfort. Rear-seat passengers with functioning backbones might prefer the access granted by the three-door over that of the five-door, but the bigger doors could be a liability in car parks. 


The body style was very understated for the performance, unfestooned as it was with bulges or wings or of course the new BMW ‘lungs’ grille. The adaptive LED headlights (a £495 option) were praised by many. 1 Series tailgates seem to have been very thinly painted on the inside, as in a quarter of the thickness that they were supposed to have. It didn’t take much to puncture the coat, leading to rust. The boot was 360 litres with the back seats up (20 litres more than a Golf R) and that figure went up to a useful 1,200 litres when they were down.

The window glass in frameless cars could stick to the rubber seals in cold weather. A dod of Gummi Pflege smeared on the seals would sort that. On early cars the positioning of the chargecooler behind the honeycomb grille under the offside headlight made the cooler very vulnerable to stone impacts. Protective mesh was put in place on later cars. Washer jet pump filters blocked up easily and cleaning them was a bit of a faff. Door mirrors could squeak on opening in warmer weather. 


In 2018, a year before the end of what many saw as the last of the rear-wheel drive ‘pocket supercars’, new M140i prices actually went down. That was a head-scratcher. Now, three years after the line came to an end, the realisation must surely soon be hitting home that there will never be any more cars like this, and the question therefore is whether used prices will fall much lower than the point they’re at now. 

We mentioned £16k as the current entry price. Here’s one for exactly that. It would be understandable if you didn’t fancy the sight of 151,000 miles on the odometer, but apart from the beaten-up boot the general condition on this 5-door Shadow from the last year of M140i manufacture bodes well for anyone thinking about racking up high mileages in one of these. 

After that, the 66,000 miles covered by this 3-door manual makes it look rather appealing at £17,400. This 2017 three-door isn’t mint but it looks like decent value for its 31,000 miles at £20,995 and you’d get more than £400 change from that amount if you went for this 23,000-mile 2016 five-door instead. 

In the PH Classifieds at the time of writing you couldn’t spend more than £30k on even the most expensive M140i. The winner of that prize was this 2018 Shadow with 18,000 miles at £29,989. Yes, it’s purple, but it looks better than that sounds. If you don’t mind white and you fancy something with low miles to lay down like a fine old wine you could do a lot worse than this one, yet another Shadow edition but with only 9,000 miles. Minty. 

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