Driving the 2007 BMW 335i Convertible puts you in a state of engineering nirvana. BMW's twin-turbo power train, launched last year, makes beautiful sounds and delivers fantastic throttle response. Oh, the 335i Convertible has plenty of available cabin gadgets plus a slick retractable hardtop, but the technology that impresses us most about this car lives under the hood.
The 335i Convertible looks really good, too, as long as you direct your gaze to the front of the car. The front and sides of the car sport subtle raised edges, which break up the otherwise too-smooth sheet metal. The front wheels sit just behind the bumper, and the hood only rises a little above them. With the hardtop up, the roofline curves over the cabin in good proportion to the rest of the car. With the top down, the 335i Convertible avoids looking like a bathtub, a problem with many four-seat convertibles. Unfortunately, the rear starts to look a little tubby, with too-high fenders over the rear wheels and a bland back end.
Retractable hardtops are trendy right now, and we've previously seen them on the Mazda MX-5, the Volvo C70, and the Volkswagen EOS. In form, the BMW's is most like the one on the Eos in the way it stacks its multiple roof panels. When the roof is up on the 335i Convertible, it feels almost as solid as a static roof, providing good insulation for the cabin. However, it takes a while to open and close, and there is only a sliver of usable trunk space when it is down.
Our review car didn't come with navigation, although it is an option. But we did have a smart key, Bluetooth cell phone integration, and BMW's premium stereo, which comes standard.
Test the tech: Summer road trip
Given that we had a convertible and some beautiful weather, we tested out the 335i Convertible with a road trip to Lake Tahoe. Our first snag hit before we left, as we figured out how many people we could take. Three people and luggage was a comfortable maximum, as there isn't much trunk room even with the top up. When we wanted to cruise around the mountains with the top down, we had to pile up our bags in one of the rear seats. BMW provides a cover that can go over the rear seats, making a secondary trunk, but it's no good if you have three people. With two people, the 335i Convertible makes a good touring car.
With the top down, the roof panels stow in the trunk, severely limiting luggage space.
All occupants had good things to say about the car's comfort over a 5-hour freeway trip, with a significant amount of time spent in heavy traffic. The front seats offered a variety of power adjustments, including the ability to extend the front of the seat for thigh support, useful for those with long legs. The rear seats aren't adjustable but have a nice contour. There's a separator between the two rear seats, which would make it very uncomfortable to try to cram three people back there.
Driving mountain roads to Lake Tahoe proved exhilarating in the 335i Convertible. Even in sixth gear, it pulled the long grades without difficulty. It was incredibly agile for passing other cars, especially all those SUVs that insisted on sitting in the left lane and barely meeting the speed limit. For part of the trip, we had the top down. At high speeds, the front-seat passengers could still hear each other, but the rear-seat passenger was left out. One danger we found was that the 335i Convertible gets far past the legal speed limit very easily, cruising above 90 mph. We often found ourselves going faster than we realized and had to lift off the accelerator before we got too far on the wrong side of the law.
Although tight on space, the 335i Convertible handles paved roads over all manner of terrain very well. It provides a comfortable ride for passengers and, with the top down, extra sun and air in a stylish package.
In the cabin
With a red leather interior, the cabin of our 335i Convertible looked a little gaudy, but the sports seats, part of the $1,900 Sport package, were comfortable and offered nice lateral support. While we like the metal strip that separates the upper and lower parts of the dashboard, the black plastic covering the center stack looks dated. We wholly approve of BMW's new steering wheel design, which uses three spokes and metal trim covering the lower parts of the curving hub.
There is a hole in the dashboard for BMW's smart key, but you don't need to use it. The key can stay in your pocket while you turn over the engine by pushing the start button on the dashboard. You also don't need to push the unlock button on the key to open the doors--if the key is in proximity to the car, you only need to touch the door handle and the lock will pop open.
BMW's stereo system lets you fine-tune the audio with this equalizer.
The standard stereo in the 335i Convertible uses 11 speakers and digital sound processing. Along with standard bass and treble settings, there is a seven-band equalizer where you can really fine-tune the sound. Another setting lets you switch between music and theater modes, the latter being surround sound. We found the audio quality of this system to be quite good, producing strong bass and excellent clarity, although the highs could have been a little brighter.
For audio sources, the standard system uses a single disc slot that plays MP3 CDs, and there is an auxiliary input in the center console. Satellite radio is available, as is an iPod/USB adaptor. A six-disc changer is available as a dealer install, which means it won't be an in-dash unit, with either a glove box or trunk mount. We were impressed by the usability of the MP3 CD interface on the simple two-line display. BMW did a good job of engineering it so you can see track information and easily navigate through folders. If you have the navigation option, the car will get an LCD where audio information will be shown, and the audio system will be controlled with iDrive.
The 335i Convertible's Bluetooth cell phone integration gave us access to our phone book.
As part of the $1,550 Premium package on our car, we also had Bluetooth cell phone integration. We were very impressed with the way this system worked with our Samsung SGH-D807 test phone. Pairing the phone was quick and easy, with the car letting us set a unique PIN code that had to be entered on the phone and on the car stereo, ensuring security. Once paired, the car's display gave us access to our phone book. Again, BMW impressed us in the clever way it used the car's two-line display to let us easily make calls from our phone book entries.
We also tried the system with a Sony Ericsson K790a and, while it paired and made calls just fine, the car couldn't access its phone book. BMW's list of compatible phones is relatively narrow and doesn't include either of our test phones.
Our test car didn't come with the navigation option, but there is one available. We've seen it on other BMWs, and it works well enough, but it doesn't stand out in any particular way.
Under the hood
The twin-turbo, 3-liter inline six-cylinder engine powering the 335i Convertible is a work of art. It sounds wonderful, and we frequently turned off the audio system so we could hear its low-tempo, perfectly controlled growl. BMW developed this twin-turbo system because it didn't want to eke any more displacement out of the inline six but wanted to compete with all of the 3.5-liter V-6 engines available today. The 335i Convertible's engine uses BMW's double VANOS system for throttle and valve control, putting out 300 horsepower at 5,800rpm. Its 300 lb-ft of torque kicks in at a low 1,400rpm.
Getting the most out of this engine using the car's smoothly shifting six-speed manual took some on-the-job training. In city driving, we had adequate boost without too much egging on, but for fast starts onto highways or freeways from a stop, we found it worked best to push it above 3,000rpm before dropping the clutch, otherwise first gear feels a little anemic. When we really laid it on, keeping the engine revving at around 5,000rpm, each upshift was dramatic, giving the car a strong kick each time. But this type of acceleration isn't easy to do without a long straightaway, as the 335i travels along nicely at 50 mph in second gear with the rpms at 5,500. The car shows no signs of strain while driving at 65 mph in third.
BMW added two turbochargers to its 3-liter engine to compete with 3.5-liter V-6 engines from other manufacturers.
During our driving through cities and on freeways, the car held steady at an average 19.1 mpg. The new EPA testing rates it at 17 mpg city and 26 mpg highway, so we came in at the low end of that. These aren't great numbers, but we've seen turbocharged four-cylinder cars get worse. An emissions rating for this car wasn't available at the time of our review.
Like most BMWs, the 335i Convertible is a great sports car but also very drivable under any circumstances, even heavy traffic. It easily negotiated hard turns on mountain roads at speed and really seemed to like it when we were able to put the power on. But during our mountain run, we noticed that the steering felt light. BMW's standard power steering gets variable assist dependent on engine speed, so we thought the light steering might be due to our rpms being too low in the turns. But then we remembered that, driving with the top down, the entire roof structure was stowed in the trunk. That top accounts for a significant amount of weight--piling it in back may help the drive wheels, but also shifts the weight distribution, which could make the steering feel light. As an option, BMW offers Active Front Steering, which controls variability based on vehicle speed and other factors, which might do a better job of coping with the weight shift.
As we would expect in a 335i, the suspension is nice and rigid, allowing no body roll in corners. But it's not an uncomfortable rigidity, so the car doesn't rattle your teeth when you drive along rough roads. The car also comes with BMW's road-holding technologies, which includes an antilock braking system that keeps the brakes dry in wet weather. The 335i Convertible also comes standard with adaptive headlights that turn into corners.
The base price for a 2007 BMW 335i Convertible is $49,100, which represents an almost $9,000 premium over the BMW 335i Coupe. Our review car also came equipped with metallic paint ($475), the Cold Weather package ($750), the Premium package ($1,550), the Sport package ($1,900), and the smart key ($500). Along with its $775 destination charge, the total price of our car was $54,450, which seems like a hefty price for a 3-series, BMW's low-end model in the U.S.
But it's also difficult to point out any similar car with a power train quite as entertaining. The Acura RL comes in at a similar price with more cabin tech, but it's not nearly as fun to drive. The Infiniti G35 costs a lot less money, and gives the 335i Convertible some serious performance competition, but the Infiniti doesn't have a convertible version.