Introduction

The BMW X4 is a swoopy, low-roofline SUV, smaller than the X6 that helped establish the Sports Activity Coupe trend a decade ago. Introduced for the 2015 model year, the X4 is unchanged for 2018. A redesigned X4 is expected to debut as a 2019 model. 

In addition to its compelling shape, the sport-luxury X4 delivers strong performance. Two distinct versions are offered, each with all-wheel drive. In the X4 xDrive28i, a turbocharged 2.0-liter four-cylinder engine makes 240 horsepower and 260 pound-feet of torque. That's sufficient to yield 0-60 mph acceleration in about six seconds. 

For swifter, more stimulating performance, BMW developed the X4 M40i, packing a turbocharged 3.0-liter inline six-cylinder engine that generates 355 horsepower and a burly 343 pound-feet. In less than five seconds, the M40i blasts from a standstill to 60 mph. Both models use an impressively competent 8-speed automatic transmission. 

Porsche's Macan is a prime competitor, with comparable specifications. One downside of the X4 stands out: the back seat is short on space, especially for passenger heads. Entry into the rear compartment is a tad challenging, too. That's the price to be paid for the lush curves that flow along the roof. 

Neither the Insurance Institute for Highway Safety nor the National Highway Traffic Safety Administration has crash-tested the X4. A rearview camera is standard, but many advanced safety features are offered only in expensive option packages. 

Adaptive cruise control, lane departure warning, and forward collision warning with automatic emergency braking are available for a fairly reasonable $1,200 additional. Blind'?spot monitoring, a head'?up display, and speed-limit display go for $1,700. Parking sensors and a surround'?view camera system add $700. 

Because the X4's low roof pillars and obstructed rear hatch roofline affect outward visibility, blind-spot monitoring is an especially prudent addition. 

For the category, the X4 looks marvelous outside, with an interior that's not far behind. 

Lineup

The 2018 BMW X4 xDrive28i ($47,600) has the 2.0-liter four-cylinder engine with all-wheel drive. Standard features include synthetic leather upholstery, power front seats, 19'?inch wheels, adaptive headlights, wood trim, a 6.5'?inch infotainment display with Bluetooth connectivity, power tailgate, and rearview camera. 

Cold Weather, Premium, and M-Sport packages are available. Options include adaptive dampers ($1,000) and Harman Kardon surround sound ($875). Apple CarPlay ($300) requires the ($1,700) navigation system. Android Auto is not available. (Prices are MSRP and do not include $995 destination charge.)

M40i ($59,250) contains the 3.0-liter inline six-cylinder engine with all-wheel drive, and comes with deeper sport seats, leather upholstery, pushbutton start, adaptive dampers, and parking sensors. The M Sport appearance package is standard. 

Walkaround

Whether the X4 is primarily a styling statement or a laudably sensible crossover model is debatable. What's not open to dispute is the vehicle's fashionable body contours, especially along the roofline. 

Like the larger X6, the X4 gives up some functionality. Based upon the conventionally profiled X3 crossover, the X4 carves away quite a lot of cargo space and some head clearance, in exchange for its dramatic fastback roof. 

Athletic in both appearance and approach to sporty driving, the X4 features bulky fenders that can wrap around available 20'?inch wheels. 

Interior

Although BMW's upright X3 crossover, from which the X4 was spun off, seats five passengers readily, the X4 barely manages four. That's because the sloping roofline slashes at least 2 inches of rear-seat headroom, compared to the X3. 

Deeply sculpted back-seat indentations for two persons affirm that the X4 isn't meant for families. Legroom also is in short supply, but head space is the main concern. 

Front seats, in stark contrast, rank above average. To obtain more sporty seats with good support, comfortable for a broad range of body types, the M-Sport package can be added. Front seats also are sportier in the M40i edition. 

Cargo capacity also is significantly compromised by the coupe'?like roof. Volume totals 17.7 cubic feet with second-row seats upright, but the cargo hold is oddly-shaped. With those back seats folded, capacity expands to 49.4 cubic feet. 

Driving Impression

Since the X4 is a BMW, ride and handling qualities are sure to satisfy the enthusiastic driver. All the more so if that driver is behind the wheel of the M40i, which is particularly adept at breezing briskly through highway curves and corners. 

Performance, too, strikes a compelling chord, no matter which engine is beneath the hood. Neither engine feels underpowered; but again, the M40i edition makes its potent turbo six-cylinder engine spring forcefully into action. 

For vehicles in this category, driving fun isn't always a strong point. Not only does the M40i's inline six excel in power delivery, it comes on strong when responses are called for, and it backs down calmly when more sedate cruising is the goal. 

BMW's smooth-shifting 8-speed automatic transmission is so carefully tuned, it almost seems to know in advance exactly when it will be called upon to downshift. Even manual-shift fans are likely to nod in agreement over this automatic's prowess. 

Like any conventional-style performance SUV or crossover, the fashionable M40i doesn't conceal its tall ride height. Essentially, it could be said that the driver sits atop the vehicle, rather than within it. 

Standard all-wheel drive ordinarily splits power in a 40/60 ratio, front/rear, but can send every bit of it to the back wheels, if needed. A performance controller can split torque side-to-side, too. Unlike some AWD systems, BMW's is intended for off-road use. 

Optional adaptive dampers produce firmer suspension responses, enhancing comfort and flexibility. 

As for fuel economy, the base X4 xDrive28i is EPA-rated at 20/28 mpg City/Highway, or 23 mpg Combined. The X4 M40i manages only 18/25 mpg City/Highway, or 21 mpg Combined. 

Summary

Both X4 models are well-equipped, but priced relatively high for what amounts to a compact crossover, despite its coupelike roofline. Even the base version features wood accents in an upmarket interior. Considering its performance, features, options, and fine infotainment systems, it may rank as good value. Still, that sleek roofline, cutting into back-seat headroom, effectively turns the X4 into a veritable two-seater, at least for long treks. 

Driving impressions by Aaron Cole, The Car Connection. James M. Flammang contributed to this report.