Sporty coupes usually sell in such small numbers that they don't earn redesigns until long after their hotter-selling sedan and CUV stablemates have been freshened. But because BMW snuck a four-door "Gran Coupe" into the 4 Series lineup (accounting for more than half its volume), the model has sold 400,000 units in four years, earning itself a redo. In all, some 2,500 parts have been redesigned for 2018, and not too surprisingly the focus is less on reprettying an already pretty package and more on improving what lies beneath.

All but the most devoted fans of the brand will need a field guide to spot the 2018s. Outside, the front and rear lighting and wheel designs are new, and non-M Sport cars get revised front and rear fascias. There are also two new colorsâSunset Orange and Snapper Rocks Blue (named for a beach on Australia's Gold Coast). The front fascia reboot connects the formerly separate lower outboard air inlets with a trim strip that aims to visually widen the front end. New sexy-specs headlamps fit the old openings, trading dual round light-pipe daytime running lights for edgier hexagonal frames, with the inboard ones now reaching horizontally over to touch the grille as on other new Bimmers. The outer pair now provides full LED illumination, featuring fixed or optional adaptive beam patterns (as part of the $2,100 Executive package). Around back, the taillamps go full-LED, as well, with wider amber turn signal elements, and the lower fascia's cross-car trim strip widens to cradle the outboard reflectors.



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Inside, a new sportier steering wheel rim is lined with a material that makes it easier to grip. There's fancier double stitching on the dash and new leather colors and trim offerings that are said to broaden the possibilities for personalizing the 4. A fancier new multifunction instrument cluster is available with the $2,300 Premium package. It provides three greatly differentiated gauge views, each tied to the default Comfort, Sport, and EcoPro driving modes. The first is very traditional BMW. Sport switches to a red color theme with a large digital speedometer reading and a gear reading inside the simplified tach. EcoPro trades the tach for an efficiency meter and a blue color scheme. Finally, the central iDrive display becomes a touchscreen adapting BMWs new look with the various functions on six separate tiles that can be arrayed as the driver wishes across two screen pages.

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So much for the skin-deep spiffs. Let's get to the functional suspension, steering, and brake upgrades. All 4s get new faster-acting antilock brake actuators (with lower-inertia moving parts) that improve braking precision and should shorten our 60-0 stopping distances by a few feet. Revised steering tuning yields slightly more effort just off center, giving way to more linear response thereafter. Fixed-roof 4s also get front and rear anti-roll bars that are stiffened by 10-15 percent, and this combined with slightly increased camber is said to boost lateral cornering performance noticeably. New damping technology increases the preload on the shock absorber piston and affords broader tuning possibilities, including improved low-speed body motion control. Order the Adaptive M Suspension ($700 by itself or part of a $1,700 track handling package), and you'll supposedly feel an even greater difference between the Comfort and Sport settings. Again, these damping changes do not apply to the convertible.

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I traveled to the Bavarian Alps in order to wring out the new 4 Series on the pristinely paved swooping switchbacks leading up to Hitler's "Eagle's Nest." These roads, once plied by supercharged Mercedes-Benz 540K staff cars, would provide the perfect opportunity for this if not for a freakish late-April snow squall that forced organizers to reshoe all our cars in Michelin Pilot Alpin winter tires. These, I can definitively report, worked wonders on the damp 38-degree pavement, generating impressive grip for the conditions. Starting out in a four-cylinder 430i convertible, I graduated midday into a 440i coupe.

Additional decisive conclusions I can share: The new multifunction cluster and center touchscreen both look great and are a joy to use. Proclamations I'm prepared to make with much less certainty: Ride quality did not seem to suffer on the precious few bumps traversed in the more tightly suspended coupe, and both cars remained remarkably even-keeled under such cornering grip as could be mustered in these conditions. Steering effort and response seemed quite appropriate for the segment, but there wasn't much to feel coming up from the greasy road surface and gummy tires. A more conclusive report generated on the drier, less pristine, better-known roads back home will come soon.

Appropriately, the modest upgrades bring modest pricing: 430i models increase by $250, and 440i models go up $200. We have always liked driving 4 Series cars almost as much as we like looking at them. By focusing more effort under the skin, BMW might have just helped balance our opinion of the fetching 4.



2018 BMW 4 Series BASE PRICE $43,195-$60,495 VEHICLE LAYOUT Front-engine, RWD/AWD, 4-pass, 2-door coupe or convertible; 5-pass, 4-door hatchback ENGINES 2.0L/248-hp/258-lb-ft turbocharged DOHC 16-valve I-4; 3.0L/320-hp/330-lb-ft turbocharged DOHC 24-valve I-6 TRANSMISSIONS 6-speed manual, 8-speed automatic CURB WEIGHT 3,500-3,950 lb (mfr) WHEELBASE 110.6 in LENGTH X WIDTH X HEIGHT 182.7 x 71.9 x 79.4 in 0-62 MPH 4.9-6.9 sec (mfr est) EPA CITY/HWY/COMB FUEL ECON 21-23/31-34/25-27 mpg ENERGY CONSUMPTION, CITY/HWY 147-160/99-109 kW-hrs/100 miles CO2 EMISSIONS, COMB 0.72-0.79 lb/mile ON SALE IN U.S. Currently