2011 BMW 3-Series

BMW's 3-Series coupes and convertibles have long been the models of reference in the near-luxury sport segment. To keep them in class-leading form five years into their current life cycle, BMW has made numerous changes, both technical and aesthetic, for model year 2011.

All versions get new front and rear fascias, the fourth-generation iDrive control interface and various other interior upgrades, while 335i versions are graced with a new iteration of BMW's exceptional, turbocharged inline 6-cylinder engines. Furthermore, the Bavarian brand has dusted off the famous and popular "is" denomination for a pair of sportier and higher-performance variants. The 335is Coupe and Convertible are exclusive to North America and are powered by a 320-horsepower version of the company's twin-turbocharged 3.0-liter inline six. They will also be available with BMW's 7-speed dual-automated-clutch DCT gearbox (with Launch Control), which is a first for the 3-Series family.

Model Lineup
While the Coupe and Convertible versions of the 335i share restyled front and rear fascias for 2011, the new 335is sport versions bear several distinctive features. The first standout element is a more sculpted M sport front fascia, at the center of which the signature twin-kidney grille is gloss black instead of the usual chrome. The side-mirror shells sport a shiny black finish as well. Standard fare includes BMW's adaptive xenon headlights that follow the road like searchlights, in sync with the steering wheel angle. They are circled with LEDs that double as daytime running lights.

Front air intakes have been maximized on both iterations, but since the Coupe is more likely to be driven on a track, its driving lamps are replaced by larger intake ducts. The M Sport side skirts on the 335is are more accentuated than on the regular 335i, and the body-colored rear fascia carries a functional air diffuser flanked by separate, single exhaust tips finished in black chrome. There are 335is badges on the trunk cover and front fenders.

The standard wheels are 18-inch alloys with five pairs of slender branches; 19-inch rims are optional. All are exclusively shod with performance run-flat tires. The sizes are 225/40R18 in front and 255/35R18 in the rear. The 335is also comes with the M Sport suspension that is optional on other 3-Series Coupes and Convertibles.

The standard gearbox is a 6-speed manual with a short-action shifter linkage that is yet another option on lesser 3-Series siblings. In the 335is, the DCT box has a sport mode and Launch Control but fewer modes and levels than the version used on the M3.

Under the Hood
The regular 335i gets an extensively reworked version of BMW's turbocharged 3.0-liter inline six engine equipped with a larger, single twin-scroll unit. It is the first engine to combine direct injection, turbocharging and the Valvetronic system, which provides fully variable valve timing and duration. Maximum output is the same, at 300 horsepower, but the 300 lb-ft torque peak is attained at 1200 rpm, about 200 rpm less than the previous design.

The new 335is versions, meanwhile, are powered by a tuned evolution of the much-lauded twin-turbo six. It produces 320 horsepower at 5900 rpm and 332 lb-ft of torque from 1500 to 5000 rpm. Flooring the accelerator past the kick-down point also triggers an overboost that will push the torque to 370 lb-ft for seven seconds. The same engine will produce 335 horses in the upcoming Z4 sDrive35is because there reportedly is room for a larger intake manifold under the roadster's long hood.

To handle the additional muscle in the 335is, engineers have used stiffer engine mounts that also improve driveline precision and stability. Since BMW of North America believes that the typical 335is buyer will likely use it for track days, the cooling system has been beefed up with an additional radiator, a more powerful cooling fan and an oil cooler.

The deep wail from the twin exhaust in full acceleration is one of the 335is' most exciting traits. To liberate it, only the last section of the exhaust system was changed from the 335i, with the sole intention of making it sound louder, deeper and richer. And does it ever work. Engineers say that this system brings no power or performance gain and that it would be too loud for current European noise standards.

BMW says the 335is Coupe will spring from zero to 60 mph in five seconds with the optional DCT gearbox (using Launch Control), and in 5.1 seconds with the manual. The 335is Convertible should take 5.2 seconds with either gearbox. The Coupe's performance compares favorably with the 4.6-second time we clocked in the M3 Coupe. Considering that the latter's 4.0-liter V8 engine develops 414 horsepower at 8300 rpm and 295 lb-ft of torque at a much loftier 3900 rpm, the relatively modest output gains of the N54B30 twin-turbo inline-six engine seem wise, since the M3 Coupe also weighs 3,704 pounds compared with the current 335i Coupe's 3,582 pounds. Independent tuners have often extracted much more from the same engine with simple changes to the engine computer. The M3 has to remain on top of the performance pyramid in the 3-Series.

Inner Space
Inside you will find a number of M Sport elements that are standard fare in the 335is. Most prominently, the new three-branch M Sport steering wheel has an impeccably shaped rim draped with perforated leather and secondary controls for the audio system, linked phone, onboard computer and some climate-control functions. On those equipped with the optional 7-speed DCT gearbox, the wheel comes with nicely sized, pull-type gearshift paddles behind the rim — downshifts with the left lever, upshifts on the right.

The sport seats are nicely sculpted and wrapped with thick Dakota leather. They offer multiple power adjustments, including lumbar support and memory for two settings. It's a pity the buttons are on the left side of the cushion and thus completely out of view. The textured Glacier Silver dark aluminum trim on the instrument panel and console works well with the black surfaces that surround it. The two large main gauges are medium gray with white numerals and "335is" etched on the tachometer's face. Other M Sport features include stainless-steel-trimmed pedals, footrest and door sills, and a leather gearshift knob with the manual gearbox.

On the Road
The 335is Coupe basically runs on the same suspension components as would a 335i with the M Sport package. The ride height of the Coupe or Convertible is the same, and all spring and shock-absorber rates and adjustments are identical. The Convertible rides slightly lower and its suspension settings are not as firm as the Coupe's, BMW engineers say. The 335is is equipped with the same electronically controlled differential as the 335i, rather than a mechanical or torque-sensing limited-slip differential. No changes for the brakes, either. The "is" gets the same disc brakes as a 335i, with vented rotors that measure 13.7 inches in diameter in front and 13.2 inches at the rear.

We drove only the Coupe at the car's launch in Portugal and only at speed, on the storied Estoril race track, a popular destination on the Formula One circuit. All the cars were running on Bridgestone RE050 A1 run-flat tires, which should be standard for U.S. cars. Even on a damp track, the virtually perfect 50/50 weight balance of the 335is comes across instantly. Steering is quick and precise and lets the driver confidently adjust the car's attitude in corners, in sync with the highly flexible, torque-rich turbocharged engine. All this remained true as we switched off all systems and drove the car without the aid of traction or stability control systems on the still-slippery surface. The 335is Coupe does roll a bit while cornering hard on a track, but all movements are well-damped. It will be just right on regular roads, even at a brisk pace.

Right for You?
The 335is Coupe will be available in June, with a base price of $50,525, destination fee included. The 335is Convertible will come earlier, in April, with a starting price of $59,075. Both cars come with just about everything enthusiasts can wish for in a 2-door 3-Series, even those who will take their car to the track on a regular basis. Even with the added power, the 335is doesn't have quite the same bite or stride as its thoroughbred sibling, the M3. That wasn't the plan. It's just a very clever assemblage of features that offers solid value, in function as well as in form. And you simply will never get enough of the marvelous howl of that sport exhaust.

A professional auto journalist for more than 25 years and the founding editor of Sympatico / MSN Autos, MarcLachapelle is a two-time winner of the Canadian Journalist of the Year award from the Automobile JournalistsAssociation of Canada, an accomplished photographer and licensed racer.