BMW M140i buying guide: the last rear-wheel drive hot hatch
The M140i is a compact hatchback with a straight-six and rear-wheel drive. This buying guide covers the B58 engine, gearboxes, known issues, tuned cars and the checks to make before you buy.
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This M140i buying guide covers one of the most special compact cars of recent years. Built from 2016 to 2019, the M140i combined a small hatchback body with a 3.0-litre straight-six and rear-wheel drive, a layout no other hot hatch offered.
Its successor moved to a front-wheel drive based platform, which makes the M140i the last rear-wheel drive BMW 1 Series. Today it is a popular used buy with strong performance at a reasonable price. Here is what to check before you buy one.
Why the M140i is special
Most hot hatchbacks use four-cylinder engines and front-wheel drive. The M140i was different. It had the smooth B58 straight-six, rear-wheel drive in most markets and the playful balance that BMW fans love.
It replaced the M135i, which used the earlier N55 engine. The M140i offered more power and torque, and it became one of the fastest cars in its class. It was available as a three-door (F21) and five-door (F20), and in some markets with xDrive all-wheel drive.
Our article on BMW M vs M Performance vs M Sport explains where M Performance models such as the M140i fit in the BMW range.
The B58 engine
The B58 is a 3.0-litre straight-six with a single twin-scroll turbocharger. In the M140i, it produces around 340 hp in many markets, with strong torque from low revs. It is known as a robust engine.
Points to check include:
- Coolant leaks: some B58 engines suffer from leaks at coolant pipes or the expansion tank. Check the coolant level and look for traces of coolant.
- Oil leaks: check around the oil filter housing and the oil pan.
- Ignition: misfires can be caused by spark plugs or ignition coils, especially on tuned cars. Our article on BMW spark plugs and ignition coils explains the intervals.
- Service history: regular oil changes with the correct approved oil.
Our comparison of the N54, N55 and B58 engines explains how the B58 compares with its predecessors.
M140i buying guide: tuned or standard?
The M140i responds very well to tuning, and many cars have been modified. Software upgrades, intakes and exhausts are common.
If you are looking at a tuned car:
- Ask for a full list of modifications and invoices from a respected specialist.
- Check the charge pipe, which can crack on tuned cars because the original part is plastic.
- Check clutch, gearbox and drivetrain for signs of strain.
- Make sure all modifications are legal in your country and declared to your insurer.
- Prefer cars with the original parts included.
A well-maintained standard car with full history is usually the safest choice.
Gearboxes
The M140i was available with a six-speed manual gearbox or an eight-speed automatic.
- Automatic: quick, smooth and popular. It suits daily driving and gives fast acceleration. Check for smooth shifts and no warning messages. Our article on BMW transmission fluid explains why the fluid matters.
- Manual: more involving and sought after by enthusiasts. Check the clutch for slipping and listen for noise from the dual-mass flywheel at idle. Our article on the BMW dual-mass flywheel explains the symptoms.
Both gearboxes are generally reliable when maintained.
Chassis, brakes and tyres
The M140i has a firm, sporty suspension and M Sport brakes. Check:
- Suspension: knocks over bumps can indicate worn bushes or mounts. Our article on worn BMW suspension bushings explains the symptoms.
- Brakes: discs and pads wear faster on cars driven hard.
- Tyres: quality tyres in matching sizes. Uneven wear can point to alignment problems. Our article on BMW wheel alignment explains why it matters.
- Differential: many cars have an open differential. Some owners fit a limited-slip differential, which can be an attractive upgrade.
Rear-wheel drive with strong torque requires good tyres, especially in wet or cold conditions.
Interior and equipment
The M140i interior is practical and well built, but it is less modern than newer BMWs. Check that the iDrive system, navigation and all electrical functions work.
Popular options include adaptive suspension, sports seats, a Harman Kardon audio system and the Shadowline trim. The five-door is more practical for families, while the three-door is lighter and often preferred by enthusiasts.
Is the M140i a good buy?
For many enthusiasts, the M140i offers the best combination of performance, practicality and price in the used BMW market. It is fast enough to challenge much more expensive cars, practical enough for daily use and relatively affordable to maintain.
As with every used performance car, the best purchase is one with complete history and careful previous ownership. Arrange an inspection with a BMW specialist and follow our complete checklist for buying a used BMW.
BMW M140i key facts
| Item | Details |
|---|---|
| Production | 2016 to 2019 |
| Body styles | F21 three-door, F20 five-door |
| Engine | B58 3.0-litre straight-six, single twin-scroll turbo |
| Power | Around 340 hp in many markets |
| Gearboxes | 6-speed manual or 8-speed automatic |
| Drive | Rear-wheel drive; xDrive in some markets |
| Known checks | Coolant leaks, charge pipe on tuned cars, history |
Frequently asked questions
Is the M140i reliable?
Generally yes. The B58 engine is robust when maintained. Check for coolant leaks and avoid poorly tuned cars.
Is the M140i rear-wheel drive?
Most M140i cars are rear-wheel drive. xDrive all-wheel drive was offered in some markets.
Manual or automatic M140i?
The automatic is quicker and suits daily driving; the manual is more involving and sought after by enthusiasts.
Should I buy a tuned M140i?
Only with full documentation of the work, legal modifications and upgraded supporting parts.
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