The 2025 BMW M340i reaches 0–100 km/h in 4.4 seconds — seriously quick for a sedan. The updated twin-turbo B58 inline-six with dual injection delivers 386 hp and 540 Nm, backed by 48 V mild hybrid. Combined-cycle consumption is quoted at 8.1 l/100 km; some owners report daily use dropping from 9.4 to 7.4 l/100 km. Suspension revisions improve comfort on rough roads compared with earlier cars.
At €71,000 in Romania, the question is whether performance and refinement justify the spend. This review covers design, driving dynamics, technology and real-world value.
What the M340i is and who it suits
The 3 Series legacy dates to 1975 with more than 20 million sold. The M340i sits between daily usability and serious performance — for enthusiasts and families wanting a capable premium sedan.
G20 facelift changes for 2025
The 3.0-litre B58B30M2 inline-six was reworked for block and bedplate durability. Dual injection optimises combustion; 48 V mild hybrid adds 11 hp for 386 hp between 5,200–6,250 rpm and 540 Nm between 1,900–4,800 rpm.
The eight-speed automatic is recalibrated for smoother, quicker shifts. RWD combined consumption is quoted at 8.7 / 7.1 / 8.1 l/100 km (urban / motorway / mixed) — improved over the previous generation.
Exterior updates include a larger kidney grille, sharper bumper lines and bigger air intakes; the rear gains a redesigned diffuser and hexagonal exhaust tips.
Inside, a minimalist centre console hosts iDrive 8.5 on the Curved Display — 12.3-inch cluster and 14.9-inch centre screen.
Target buyers
M340i aims for high performance without sacrificing daily comfort — suitable for keen drivers and families. 481-litre boot fits six carry-on bags; standard sport seats offer strong support and adjustment.
Adaptive suspension is tuned for varied surfaces and modes — a daily companion, not only a weekend car.
Position between 330i and M3
From about €57,000, the M340i sits above the 255 hp 330i and well below a full M3. Visual intensity is lower than M3, yet 0–100 km/h in 4.4 seconds (4.1 s xDrive) rivals base M3 acceleration. The softer chassis and quieter cabin make it the civilised alternative — much of the M3 substance at lower cost.
Exterior and interior design
Evolution, not revolution: athletic proportions in a contemporary 3 Series skin.
Grille and M Sport details
Inverted L-shaped LED headlamps mark the generation. Mesh kidney grille and large hexagonal intakes dominate the front. Extended Shadowline (€285) adds black grille and dark chrome exhaust tips; full Shadowline (€570) includes adaptive LED with black inlays. Long wheelbase and short overhangs suit 19-inch wheels.
Fire Red paint
Fire Red (~€617) is a 2025 option alongside Arctic Race Blue Metallic — deep red with black and orange flake, vivid in sun, darker in shade. BMW Individual Frozen Pure Grey and Frozen Portimao Blue are available. M Sport models get new 19-inch Style 995M double-spoke wheels in bi-colour or Jet Black.
Minimalist interior with iDrive 8.5
Clean cockpit with fewer switches; curved display appears to float above the panel. Centre console feels sporty and enclosed with touch iDrive surface and automatic gear selector.
New M steering wheels include a three-spoke wheel with flat bottom and subtle red top stripe.
Materials
Standard Sensatec perforated black upholstery; Vernasca leather options from about €1,425. Ash Grey trim can be swapped for carbon fibre (~€285). Cascade ambient lighting around new centre vents offers nine colours. Standard M Aluminum Rhombicle trim; optional Ash Grey open-pore wood, fine brushed aluminium or carbon fibre.
Performance and dynamics
3.0-litre I6 with 48 V
386 hp and 540 Nm with dual injection and mild hybrid support. Consumption quotes: 8.7 l/100 km urban, 7.1 motorway, 8.1 mixed.
Acceleration
RWD 0–100 km/h in 4.4 s; xDrive in 4.1 s. Independent tests recorded down to 4.21 s. Intermediate sprints — 60–100 km/h in 2.4 s, 80–120 km/h in 3.1 s — were supercar territory a decade ago.
Drive modes
Comfort defaults soft and light; Sport sharpens shifts and throttle; Sport+ reduces electronic intervention. Eco Pro saves fuel; Adaptive adjusts to conditions.
ZF8 and M Sport differential
The eight-speed ZF is smooth in Comfort, aggressive in Sport; STEPTRONIC paddles give manual control. The electro-mechanical M Sport differential limits slip and aids corner exit traction.
Adaptive M suspension, sport variable steering, gearbox and diff make the M340i tame in town and exciting on mountain roads.
Daily comfort and technology
Adaptive suspension
Comfort mode is controlled without being harsh — noticeably more forgiving than before. Sport adds stiffness without ruining ride quality. Reinforced rear damper mounts improve the sport/comfort balance; steering effort drops in Comfort.
Harman Kardon audio
Optional 16-speaker Harman Kardon with 464 W seven-channel amp delivers strong clarity and balance at volume.
iDrive 8.5 vs 7
Large map-centric layout, QuickSelect shortcuts, climate and seat controls on the curved screen or by voice.
Space and ergonomics
Supportive front seats with memory and lateral support; decent rear space though panoramic roof affects front headroom feeling. Practical door pockets and 481-litre boot.
Minor issues
Digital key problems after iOS 18 updates and with iPhone 16 have been reported. Paint can be soft and scratch-prone — use quality microfibre only.
Price and value at €71,000
List price in Romania starts around €71,000; xDrive from about €57,000 on some lists (verify current configurator). A 2023 example with ~6,732 km has been advertised near €61,000 used.
Rivals: Mercedes-AMG C43 ~€84,000, Audi S5 ~€78,000. Quarter-mile tests place M340i at 12.5 s, ahead of S5 (12.8 s) and C43 (12.9 s).
Conclusion
The 2025 M340i confirms BMW still knows sport sedans. 386 hp, 4.4 s to 100 km/h and 8.1 l/100 km mixed consumption balance thrill and running costs.
At €71,000, value depends on your priorities. It delivers roughly 90 % of base M3 experience at a lower price with more daily comfort. Adaptive suspension, Harman Kardon and iDrive 8.5 complete a coherent package.
Drawbacks: delicate paint, occasional digital-key glitches. For enthusiasts wanting a versatile premium sport sedan, the investment is defensible — not as radical as a full M3, which is precisely the point for everyday use.
Key takeaways
- 386 hp B58 with 48 V mild hybrid; 0–100 km/h in 4.4 s
- 8.1 l/100 km mixed consumption is reasonable for the performance
- €71,000 buys adaptive suspension, optional Harman Kardon and iDrive 8.5
- Residual value after five years quoted around 51 % — competitive in class
- Strong choice if you want most of an M3 with more comfort and lower cost
For buyers seeking a premium sport sedan without sacrificing practicality, the 2025 M340i delivers driving pleasure with usable day-to-day credentials.
