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Porsche of South Shore

Boxster S vs Z4 vs SLK55 AMG

Performance Comparison between the Porsche Boxster S
and Mercedes-Benz SLK55 AMG and the BMW Z4 sDrive35is

So who is the clear winner? The Porsche Boxster S...and we explain why.

The Boxster S is the most capable 2-seat roadster at its price point. Porsche's decades of motorsport experience have provided the blueprint for generations of class-leading sports cars.  In the late 1990s, Porsche unveiled the Porsche Boxster to critical acclaim.  A proper blend of luxury and scalpel-like precision on the road, the Boxster has proven to be a peerless and extremely desirable sports car.

At first glance the Boxster S may seem short on power compared to its competitors, but these numbers do not tell the whole story.  The Boxster S weighs only 2,976 lbs., nearly 600 lbs. lighter than the Mercedes-Benz SLK55 AMG and the BMW Z4 sDrive35is.  In addition, it utilizes a motorsports-derived mid-engine placement giving it perfect balance and road-holding manners.  The Boxster S features a 3.4L flat-6, which shares its architecture with the legendary Porsche 911 Carrera.  This exotic engine revs extremely high, giving it a very sporting character compared to other manufacturers' powertrains.  The engine features technologies such as VarioCam Plus (Variable Valve Timing), Direct Fuel Injection (DFI), and Integrated Dry Sump Lubrication.  A Boxster S can be configured with Active Sport Exhaust, allowing for a more authoritative tone at the push of a button.  This power can be routed through an optional Porsche Doppelkupplung (PDK) 7-speed dual-clutch transmission, the most advanced of its kind in its segment.

The chassis and suspension of the Porsche Boxster S have been tuned to provide a perfect harmony of lighting-quick reflexes and long haul comfort.  Optional Porsche Active Suspension Management (PASM) allows the driver to adjust these suspension settings on the fly, or leave the adjustments up to the advanced on-board computer.  The Boxster S utilizes extremely powerful brakes that are easy to modulate and provide class-leading performance.  Porsche Ceramic Composite Brakes (PCCB) are an even more capable option, resistant to fade and heat stress of sustained high-performance driving.  Nineteen-inch wheels and high performance tires round out the package, with 20-inch 911 wheels as an option.  Porsche Torque Vectoring (PTV) and Dynamic Transmission Mounts are available technologies to help ensure power is transferred to the ground in the quickest and most efficient manner.

Base Price








Suspension, front

Suspension, rear



Tire size f, r



Track f/r


Weight dist. F/r

Cargo Capacity

EPA Mileage

0-60 MPH

Top Speed

Mercedes-Benz SLK55 AMG


32-valve DOHC V-8

5.5 liters (333 cu in)

415 hp @ 6800 rpm

398 lb-ft @ 4500 rpm

7-speed automatic


Hydraulically assisted

Strut-type, coil springs

Multilink, coil springs

Vented discs, ABS

Continental ContiSportContact

235/40YR-18, 255/35YR-18

L x W x H 163.2 x 79.0 x 51.2 in

95.7 in

61.0/61.7 in

3549 lb


10.1/6.4 cu ft (top up/down)

19/28 mpg

4.5 seconds

155 mph

Porsche Boxster S
Boxster S


24-valve DOHCflat-6

3.4 liters (210 cu in)

315 hp@ 6700 rpm

266 lb-ft@ 4500-5800 rpm

7-speed automatic


Electrically assisted

Strut-type, coil springs

Multilink, coil springs

Vented discs, ABS

Pirelli PZero

235/35YR-20, 265/35YR-20

L x W x H 172.2 x 77.9 x 50.0 in

97.4 in

60.1/60.6 in

2976 lb


5.3/4.6 cu ft(front trunk/rear)

21/30 mpg

4.5 seconds

172 mph

BMW Z4 sDrive35is
Z4 sDrive35is


24-valve DOHCtwin-turbo I-6

3.0 liters (182 cu in)

335 hp@ 5900 rpm

332 lb-ft@ 1500 rpm*

7-speed automatic


Electrically assisted

Control arms, coil springs

Multilink, coil springs

Vented discs, ABS

Bridgestone Potenza RE050A

225/35YR-19, 255/30YR-19

L x W x H 167.0 x 70.5* x 50.6 in

98.3 in

59.5/60.5 in

3549 lb


10.9/6.4 cu ft(top up/down)

17/24 mpg

4.7 seconds

155 mph

The Boxster S utilizes Porsche Stability Management (PSM) which incorporates a sophisticated traction and stability control system to safely correct any dangerous driver inputs.  This system can be completely disengaged for track duty however.   Multiple airbags and roll-over protection are standard features. The Boxster S has an unparalleled level of customization available to its drivers.  Multiple interior configurations feature leather, Alcantara, fine wood trims, carbon fiber, and aluminum.  Optional Bose or Burmester high-end sound systems are available replete with Bluetooth, satellite radio, etc.  The possibile configurations are endless!

A sports car is measured by how well it rewards its driver.  A mid-engine configuration with a dual-clutch transmission is usually reserved for vehicles that cost in excess of $200,000.  The dynamic sensations, nimble handling, and wail of the legendary flat-6 provided by the Boxster S are hard to describe in words.  We invite you for a test drive to feel for yourself what it is to drive a Porsche!

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