Certified Benz & Beemer Compares 2011 Porsche 911 VS 2011 Mercedes SLK Near Phoenix, AZ

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2011 Porsche 911

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2011 Mercedes SLK

Safety Comparison

For enhanced safety, the front seat shoulder belts of the Porsche 911 Coupe are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The Mercedes SLK doesn’t offer height-adjustable seat belts.

The 911 offers all wheel drive to maximize traction under poor conditions, especially in ice and snow. The SLK doesn’t offer all wheel drive.

Both the 911 and the SLK have standard driver and passenger frontal airbags, front side-impact airbags, head airbags, front seatbelt pretensioners, four wheel antilock brakes, traction control and electronic stability systems to prevent skidding.

Warranty Comparison

The 911’s corrosion warranty is 6 years and unlimited miles longer than the SLK’s (10/unlimited vs. 4/50,000).

Reliability Comparison

A reliable vehicle saves its owner time, money and trouble. Nobody wants to be stranded or have to be without their vehicle while it’s being repaired. Consumer Reports predicts that the 911’s reliability will be 38% better than the SLK.

J.D. Power and Associates’ 2010 Initial Quality Study of new car owners surveyed provide the statistics that show that Porsche vehicles are better in initial quality than Mercedes vehicles. J.D. Power ranks Porsche first in initial quality, above the industry average. With 4 more problems per 100 vehicles, Mercedes is ranked third.

J.D. Power and Associates’ surveys of the owners of three-year-old cars provide the long-term dependability statistics that show that Porsche vehicles are more reliable than Mercedes vehicles. J.D. Power ranks Porsche first in reliability. With 32 more problems per 100 vehicles, Mercedes is ranked 9th.

Engine Comparison

The 911 has more powerful engines than the SLK:



911 3.6 DOHC 6 cyl.

345 HP

288 lbs.-ft.

911 S 3.8 DOHC 6 cyl.

385 HP

310 lbs.-ft.

911 GT3 3.6 GT3 6 cyl.

435 HP

317 lbs.-ft.

911 Turbo 3.8 turbo 6 cyl.

500 HP

480 lbs.-ft.

911 Turbo S 3.8 turbo 6 cyl.

530 HP

516 lbs.-ft.

SLK300 3.0 DOHC V6

228 HP

221 lbs.-ft.

SLK350 3.5 DOHC V6

300 HP

265 lbs.-ft.

As tested in Car and Driver the Porsche 911 is faster than the Mercedes SLK350 (automatics tested):


911 S


Zero to 60 MPH

4.1 sec

4 sec

5.5 sec

Quarter Mile

12.5 sec

12.5 sec

14 sec

Speed in 1/4 Mile

113 MPH

113 MPH

102 MPH

The flat cylinder configuration of the boxer engine in the 911 lowers its center of gravity, enhancing handling stability. The SLK doesn’t offer a boxer engine configuration.

Fuel Economy and Range Comparison

On the EPA test cycle the 911 RWD gets better fuel mileage than the SLK:




19 city/27 hwy

19 city/26 hwy


911 S/Auto

19 city/26 hwy

19 city/25 hwy


Brakes and Stopping Comparison

For better stopping power the 911’s brake rotors are larger than those on the SLK:


911 Opt.



Front Rotors

13 inches

13.8 inches

11.8 inches

13 inches

Rear Rotors

13 inches

13.8 inches

10.9 inches

11.4 inches

The 911’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the SLK350 are solid, not vented.

The 911 offers optional heat-treated ceramic brake rotors, which last ten to twenty times as long as conventional cast iron rotors, don’t rust, don’t fade during repeated high speed braking, and their lighter weight contribute to better braking, handling and acceleration. The SLK doesn’t offer ceramic brake rotors.

The 911 stops much shorter than the SLK:



80 to 0 MPH

184 feet

202 feet

Road & Track

70 to 0 MPH

145 feet

175 feet

Car and Driver

60 to 0 MPH

94 feet

112 feet

Motor Trend

60 to 0 MPH (Wet)

127 feet

130 feet

Consumer Reports

Tires and Wheels Comparison

For better traction, the 911 has larger standard tires than the SLK (F:235/40R18 & R:265/40R18 vs. F:225/45R17 & R:245/40R17). The 911 GT2 RS Coupe’s tires are larger than the largest tires available on the SLK (F:245/35R19 & R:325/30R19 vs. F:225/45R17 & R:245/40R17).

The 911’s standard tires provide better handling because they have a lower 40 series profile (height to width ratio) that provides a stiffer sidewall than the SLK’s standard 45 series front tires. The 911’s optional 235/35R19 front and 295/30R19 rear tires have a lower 35 series front and 30 series rear profile than the SLK’s optional 40 series front and 35 series rear tires.

For better ride, handling and brake cooling the 911 has standard 18 inch wheels. Smaller 17 inch wheels are standard on the SLK. The 911’s optional 19 inch wheels are larger than the 18 inch wheels optional on the SLK.

Suspension and Handling Comparison

The 911 offers an optional driver-adjustable suspension system. It allows the driver to choose between an extra-supple ride, reducing fatigue on long trips, or a sport setting, which allows maximum control for tricky roads. The SLK’s suspension doesn’t offer adjustable shock absorbers.

The 911 Cabriolet handles at .92 G’s, while the SLK350 pulls only .87 G’s of cornering force in a Car and Driver skidpad test.

Passenger Space Comparison

The 911 has standard seating for 4 passengers; the SLK can only carry 2.

The 911 has 15.2 cubic feet more passenger volume than the SLK (64 vs. 48.8).

Ergonomics Comparison

The 911’s instruments include an oil pressure gauge and a temperature gauge – which could save your engine! Often ‘idiot lights’ don’t warn you until damage has been done. The SLK does not have an oil pressure gauge.

Advanced Key System available on the 911 allows the driver to unlock the doors, trunk and start the engine all without removing a key from pocket or purse. This eliminates searching for keys before loading groceries, getting in the car in bad weather or making a hurried start to your trip. The Mercedes SLK doesn’t offer an advanced key system.

The 911’s rain-sensitive wipers adjust their speed and turn on and off automatically based on the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The SLK’s standard manually variable intermittent wipers have to be constantly adjusted.

The SLK’s optional cornering lamps activate a lamp on the front corner when the turn signal is activated. The 911’s optional adaptive cornering lights turn the actual headlight unit up to several degrees, depending on steering wheel angle and vehicle speed. This lights a significant distance into corners at any speed.

The 911’s standard power mirror controls are mounted on the door for easy access. The SLK’s standard power mirror controls are on the center console where they can’t be seen without the driver completely removing his eyes from the road.

The 911’s optional air conditioned front seats cool the driver and front passenger and help take the sting out of hot leather in Summer. The SLK doesn’t offer air conditioned front seats.

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