Take a peek around the new 2011 135i and you’ll be hard pressed to notice anything new. Styling’s the same, both inside and out. Even the wheel choices are identical to the cars sitting at dealer lots for the past two years. Sure, the two-pedal cars have a new shift knob and new paddle shifters but — actually, those two additions foretell something new and significant under the surface.

For the 2011 model year, the 135i is no longer offered with a traditional automatic transmission. In the old six-speed’s place is a seven-speed dual-clutch transmission; BMW named its box DCT, an English abbreviation to make life easier for us Americans who struggle to properly pronounce "doppelkupplungsgetriebe." It originally debuted as a late addition to the current M3, and until now wasn’t ever bolted to a six-cylinder engine. It’ll also be available on the limited “is” versions of the Z4 and 335, but the 135i is the first car to pair DCT with the new single-turbo N55 motor. The less expensive, naturally aspirated 128i will continue on with a six-speed Steptronic automatic, which is a $1375 option. The dual-clutch 135i demands a $200 higher premium over the base manual transmission, or $1575.

As mentioned, the 2011 135i’s engine is new as well, and while the transmission gained one extra gear, the engine lost one turbocharger, leaving it with half the original number. What it lost in turbo count it gained in the form of Valvetronic, BMW’s clever throttleless fuel delivery system. This change allows the engine to reach its peak torque of 300 lb-ft 100 rpm earlier than the twin-turbo it replaces, at a diesely-low 1200 rpm. We covered the new engine, which BMW calls the N55, in depth a few months ago.
What we weren’t able to talk about when we wrote that technology article is how the N55 actually drives compared to the outgoing N54 motor, and in the time since we’ve experienced it in both the new 535i and the 2011 X5 xDrive35i. But we still hadn’t driven it in a car that previously used the N54, meaning this 135i drive was quite significant. Before Kilometer existed, our team actually spent a full year with an early 135i and really grew to love its twin-turbo engine.

BMW will tell you the new motor is just like the old one, only more responsive and with a slightly stretched torque plateau. But there are some noticeable differences between the two. We can’t say with any solid test numbers for support that one engine is quicker than the other, but from a seat-of-the-pants standpoint the N55 doesn’t have the sharp edge of the engine it replaces. The torque arrives plenty early, but in a smooth wave rather than a crashing one. Perhaps it’s the result of Valvetronic refining the feel of the engine or maybe it’s the large, variable vane turbocharger coming on in one smooth burst, but there’s a definite difference. Many drivers will enjoy this newfound comfort, but owners jumping from the old twin-turbo engine might have to grow into the less forceful delivery.

The same added smoothness is noticeable once underway and in higher gears, as well. The N54 had a surging feel, like each turbocharger was competing to make more power than the other. This resulted in a high-energy car that seemed to be putting every possible bit of effort into performing, diving forward like a galloping horse. The new motor makes the work it is doing feel effortless, with no real indication of exhaustion or urgency.

If the 2011 model year does send the 135i’s official 0-60 mph times below five seconds, we suspect credit won’t go to the new motor but instead to the seven-speed dual-clutch gearbox. It provides strong, confident launches and snappy shifts without the typical power interruption of a traditional automatic or even manual with a lazy driver at the helm. The burps and pops of unburned fuel shooting through the exhaust during those milliseconds between shifts inject back in some of the spunky attitude the single-turbo engine took away.

Through the bends of the “Lightning” track at New Jersey Motorsports Park, the new transmission was very impressive. Left to pick shift points on its own but with “sport” mode engaged, the computers responsible for shifting did a pretty decent job of picking the right gears for the situation, though in a few long sweeping corners there we did find the car jumping up an extra gear only to downshift as we applied throttle when the track straightened back out. No big deal though, because we actually found ourselves wanting to slap the shifter over to manual mode for the first time in a non-M-badged BMW.

Gone are the company’s old wheel-mounted shift paddles, which served double-duty for both down- and upshifts. We likened this approach to putting a gun’s safety on the trigger. The 2011 135i instead has the same paddles as the M3, one on the left for downshifts and one on the right for grabbing a higher gear. They’re also easier to reach behind the wheel’s rim, whereas the old paddles were integrated inside the rim, more like buttons. Buyers who would have gone for the automatic anyway will be pleased by the DCT’s quick, crisp shifts, and BMW has also exponentially raised the odds of a typical manual transmission shopper saying goodbye to the third pedal. We just hope (selfishly) that the added price will deter at least some buyers, otherwise the manual option may disappear completely. Certainly the DCT will deliver quicker acceleration and lap times for most drivers, but there’s something to be said for the visceral connection the old six-speed adds to the 135i experience.

Is anything else new for the 135i this year? Take a close look at the online build configurator and you might notice a few small changes in how the packages and options are arranged. Most noticeable are the additional options of automatic high beams, a $250 special request-only option that’s been added, as well as a new premium sound system. The latter is a 10-speaker, 300-watt system from Harman-Kardon, and it’ll cost $875.

The 2011 BMW 135i goes on sale any day now, and at the dealership you’ll find a car that’s the same, only a bit different. Still great, but in some ways better. Official EPA fuel economy ratings haven’t been announced, but expect the DCT car to gain a few mpg and thanks to the new single-turbo motor, the manual car may see a slight gain as well. But one thing’s for sure — the 135i is a loveable little sports car, and the addition of a dual-clutch makes it even easier to enjoy.

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