Review: 2010 BMW Z4 SDrive35i Roadster

The 2010 BMW Z4 has a new optional power plant and suspension package, badged the sDrive35i, this is no grandma's roadster; gone are the days of the slow moving predecessor the Z3 and the complacent factory Z4 convertible. The sDrive35i is its own machine, with a hard convertible top and a powerful direct fuel injected 300 horsepower 3.0 liter twin turbocharged inline six cylinder; the sDrive35i is an Autobon force to be reckoned with. BMW has long had a history of sports performance, but the sDrive35i wears no such M badge. The BMW sDrive35i is now in a class of its own with combinations of the finest cars. Cues from some of the most successful cars have been used to create this finely revised and elegantly tuned roadster sport coupe. With the Z4 sDrive35i you get the best of both worlds, first you get a roadster with a convertible hard top similar to the likes of the Lexus LS430 or the Mercedes Benz SL line of roadsters, then you get a power plant that has just enough extra cylinders to give you some torque along with fuel economy and inline twin turbochargers in case you have the need for speed; similar setups have been seen on such almighty engines as the 2jz-gtte 3.0 liter from the Toyota Supra twin turbo and the older model r34 chassis Nissan Skyline GTR. With a strong competitive engine and straight line performance to back it up such as 0-60 in 4.8 seconds and a ripping 13.5 second at 106 mph there's no doubt that the sDrive35i will be a formidable competitor against the likes of Mercedes Benz and Porsche.

So, how is this beast of an engine getting its tire squealing power to the rear wheels? In two ways, either through a contemporary six speed manual shift gear box or a highly complex seven speed dual clutch semi-automatic transmission with paddle shift abilities. The Z4 sDrive35i is the first BMW aside from the M3 to utilize the application of a double clutch gear box. The shifter in the Z4 sDrive35i is quite similar to ones found in the 7 series, X6, and X5. The paddle shifting orientation is also different on the Z4 sDrive35i when compared to its step brother the M3. On the steering wheel the shift paddles are used by pulling to upshift and pushing down to downshift, which is backwards from the M3 where the paddles on the right side are used to shift up and the left to go down. The Z4 sDrive35i also lacks the adjustable shift programs found in the M3, so your stuck with the preprogrammed shift patterns of the engine and transmission control unit. Accidentally brushing the redline in manual mode will cause an automatic upshift; taking all the fun from the control of the driver. However, a sports BMW wouldn't be a sports car without something for the driver to play with and customize, hence the dynamic drive control system where the driver has total control over the stiffness of the optional user adjustable M suspension. There are three different settings: normal, sport, and sport plus modes. When using the sport mode it allows the engine's throttle response to be faster and more aggressive, the power steering to become heavier for more control and less chance of error, and the gear shifting to be quicker. The sport plus mode is the setting all real enthusiasts will choose which de-activates the dynamic traction control and allows for wheel spin and a little fish tailing action. The adjustable suspension is soft and care free in the normal mode, but when sport or sport plus is activated it becomes very stiff and rigid for superior handling.

So is the Z4's sDrive35i option worth it? Well you'll have to be the judge of that, the sDrive35i package cost on average $10,000 more than the standard 255 horsepower Z4, but is in competition with the likes of the Chevrolet Corvette, SLK class Mercedes, and Audi TT roadster. At the end of the day you'll know you have a top of the line BMW product that has proven over time to be solid and reliable.

VEHICLE TYPE: front-engine, rear-wheel-drive, 2-passenger, 2-door roadster
PRICE AS TESTED: $65,345 (base price: $52,475)
ENGINE TYPE: twin-turbocharged and intercooled DOHC 24-valve inline-6, aluminum block and head, direct fuel injection
Displacement: 182 cu in, 2979cc
Power (SAE net): 300 bhp @ 5800 rpm
Torque (SAE net): 300 lb-ft @ 1400 rpm
TRANSMISSION: 6-speed manual
DIMENSIONS:
Wheelbase: 98.3 in Length: 166.9 in Width: 70.5 in Height: 50.8 in
Curb weight: 3520 lb
C/D TEST RESULTS:
Zero to 60 mph: 4.8 sec
Zero to 100 mph: 11.7 sec
Zero to 130 mph: 20.9 sec
Street start, 5-60 mph: 5.7 sec
Standing ¼-mile: 13.5 sec @ 106 mph
Top speed (governor limited): 149 mph
Braking, 70-0 mph: 161 ft
Roadholding, 200-ft-dia skidpad: 0.83 g

FUEL ECONOMY:
EPA city/highway driving: 17/25 mpg
C/D observed: 17 mpg
Source: http://www.caranddriver.com/reviews/car/09q2/2009_bmw_z4_sdrive35i_manual-short_take_road_test