The BMW X4 (F26) M40i, produced from 2015 to 2018, represents a performance-oriented variant within the first generation of the X4 Sports Activity Coupe (SAC). Positioned as a near-flagship trim, it bridged the gap between the standard X4 models and the full-fledged X4 M. The M40i aimed to deliver a compelling blend of luxury, practicality, and engaging driving dynamics, appealing to buyers seeking a sportier SUV experience without the outright track focus of the ‘M’ designation. It was primarily marketed in North America, Europe, and Asia, offering a premium alternative in the burgeoning compact luxury crossover segment.
Technical Specifications
| Brand | BMW |
| Model | X4 |
| Generation | X4 (F26) |
| Type (Engine) | M40i (360 Hp) xDrive Steptronic |
| Start of production | 2015 |
| End of production | 2018 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SAC |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (economy) – urban | 11.3 l/100 km (20.8 US mpg, 25 UK mpg, 8.8 km/l) |
| Fuel consumption (economy) – extra urban | 7 l/100 km (33.6 US mpg, 40.4 UK mpg, 14.3 km/l) |
| Fuel consumption (economy) – combined | 8.6 l/100 km (27.4 US mpg, 32.8 UK mpg, 11.6 km/l) |
| CO2 emissions | 199 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.9 sec |
| Acceleration 0 – 62 mph | 4.9 sec |
| Acceleration 0 – 60 mph | 4.7 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 4.9 kg/Hp, 204 Hp/tonne |
| Weight-to-torque ratio | 3.8 kg/Nm, 263.5 Nm/tonne |
| Power | 360 Hp @ 5800-6000 rpm |
| Power per litre | 120.8 Hp/l |
| Torque | 465 Nm @ 1350-5250 rpm (342.97 lb.-ft. @ 1350-5250 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | N55B30A |
| Engine displacement | 2979 cm3 (181.79 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 84 mm (3.31 in.) |
| Piston Stroke | 89.6 mm (3.53 in.) |
| Compression ratio | 10.2:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Twin-power turbo, Intercooler |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Kerb Weight | 1765 kg (3891.16 lbs.) |
| Max. weight | 2430 kg (5357.23 lbs.) |
| Max load | 665 kg (1466.07 lbs.) |
| Trunk (boot) space – minimum | 500 l (17.66 cu. ft.) |
| Trunk (boot) space – maximum | 1400 l (49.44 cu. ft.) |
| Fuel tank capacity | 67 l (17.7 US gal | 14.74 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load with brakes (12%) | 2400 kg (5291.09 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Permitted towbar download | 100 kg (220.46 lbs.) |
| Length | 4671 mm (183.9 in.) |
| Width | 1901 mm (74.84 in.) |
| Height | 1624 mm (63.94 in.) |
| Wheelbase | 2810 mm (110.63 in.) |
| Front track | 1610 mm (63.39 in.) |
| Rear (Back) track | 1600 mm (62.99 in.) |
| Ride height (ground clearance) | 204 mm (8.03 in.) |
| Drag coefficient (Cd) | 0.36 |
| Minimum turning circle (turning diameter) | 11.9 m (39.04 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 8 gears, automatic transmission Steptronic |
| Front suspension | Independent coil spring |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 245/45 R19 98W/Y; 275/40 R19 101W/Y |
| Wheel rims size | 8.5J x 19; 9.5J x 19 |
Powertrain & Engine Architecture
The heart of the X4 M40i is the BMW N55B30A, a 3.0-liter inline-six cylinder engine. This engine, a descendant of the highly-regarded N54, utilizes a single twin-scroll turbocharger, direct fuel injection, and Double-VANOS variable valve timing. The N55 was known for its robust construction and ability to handle increased boost pressures, making it a popular choice for tuning. The engine produces 360 horsepower at 5800-6000 rpm and 343 lb-ft of torque from 1350-5250 rpm. This power is delivered to all four wheels via BMW’s xDrive all-wheel-drive system and an eight-speed Steptronic automatic transmission. The Steptronic transmission offers both automatic shifting and manual control via steering wheel-mounted paddles. The transmission’s programming is geared towards performance, with quicker shift times and more aggressive downshifts compared to standard X4 models.
Driving Characteristics
The X4 M40i delivers a noticeably more engaging driving experience than its four-cylinder counterparts. The potent inline-six provides strong acceleration, with a 0-60 mph time of around 4.7 seconds. The xDrive system provides excellent traction, particularly in inclement weather, while the eight-speed automatic transmission ensures smooth and responsive gear changes. While not as overtly sporty as a dedicated performance SUV, the M40i offers a well-balanced ride, combining comfort with capable handling. The steering is precise and well-weighted, providing good feedback to the driver. Compared to the X4 28i, the M40i feels significantly more powerful and responsive, while the difference between it and the full-blown X4 M is more nuanced, with the M offering a more track-focused suspension and even greater power output.
Equipment & Trim Levels
The M40i trim came standard with a generous array of features, including leather upholstery, power-adjustable front seats with memory function, a premium sound system, and a navigation system. Exterior features included unique M Sport styling cues, such as aggressive front and rear bumpers, side skirts, and a rear spoiler. Optional extras included adaptive suspension, head-up display, and a panoramic sunroof. Interior trim options allowed for customization, with choices ranging from aluminum to wood accents. The M40i was positioned as a premium trim, and as such, it offered a higher level of standard equipment than the base X4 models.
Chassis & Braking
The X4 M40i features a robust chassis with independent suspension at all four corners. The front suspension utilizes coil springs and struts, while the rear suspension employs a multi-link setup. The suspension is tuned for a balance of comfort and handling, providing a relatively compliant ride without sacrificing cornering stability. Braking duties are handled by ventilated discs at all four wheels, providing ample stopping power. The M40i also benefits from BMW’s Dynamic Stability Control (DSC) system, which helps to maintain stability during cornering and emergency maneuvers.
Market Reception & Comparison
The X4 M40i was generally well-received by automotive critics, who praised its powerful engine, engaging driving dynamics, and luxurious interior. It was often seen as a compelling alternative to rivals such as the Porsche Macan and Audi SQ5. Fuel economy was considered reasonable for a performance SUV, with combined fuel consumption figures around 27.4 US mpg. Reliability was generally good, although some owners reported minor issues with the electronic systems. Compared to the X4 28i, the M40i commanded a significant price premium, but many buyers felt the added performance and features were worth the extra cost.
Legacy
The N55 engine, found in the X4 M40i, has proven to be a durable and reliable powerplant when properly maintained. The eight-speed Steptronic transmission is also known for its longevity. On the used car market, the X4 M40i holds its value relatively well, due to its desirable combination of performance, luxury, and practicality. While newer generations of the X4 have since been introduced, the F26 M40i remains a popular choice for buyers seeking a sporty and refined compact luxury SUV.
