Certified Benz & Beemer Compares 2011 Mercedes Benz SL-Class VS 2011 Porsche 911 Near Phoenix, AZ

For enhanced safety, the front seat shoulder belts of the Mercedes SL-Class 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 Porsche 911 Cabriolet doesn’t offer height-adjustable seat belts.

The SL-Class offers an optional collision warning system, which detects an impending crash through forward mounted sensors and flashes a bright light and sounds a loud, distinctive tone to warn the driver to brake or maneuver immediately to avoid a collision. The 911 doesn't offer a collision warning system.

The SL-Class offers optional Parktronic™ to help warn the driver about vehicles, pedestrians or other obstacles behind or in front of their vehicle. The 911 doesn’t offer a front parking aid.

The SL-Class has standard mbrace, which uses a global positioning satellite (GPS) receiver and a cellular system to get driving directions, remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The 911 doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies.

Both the SL-Class and the 911 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.

The Mercedes SL-Class weighs 538 to 1480 pounds more than the Porsche 911. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.

There are over 55 percent more Mercedes dealers than there are Porsche dealers, which makes it much easier to get service under the SL-Class’ warranty.

The SL-Class has more powerful engines than the 911:

As tested in Car and Driver the SL63 AMG is faster than the Porsche 911 S (manual transmissions tested):

An engine control system that can shut down half of the engine’s cylinders helps improve the SL-Class V12’s fuel efficiency. The 911 doesn’t offer a system that can shut down part of the engine.

The SL-Class has 4.2 gallons more fuel capacity than the 911 RWD’s standard fuel tank (21.1 vs. 16.9 gallons), for longer range between fill-ups. The SL-Class has 3.4 gallons more fuel capacity than the 911 AWD/GT2’s standard fuel tank (21.1 vs. 17.7 gallons).

For better stopping power the SL-Class’ front brake rotors are larger than those on the 911:

The SL-Class’ brakes have 7% more swept area (the area covered by the brake pads) than the 911 with its standard brakes (678 vs. 634 square inches), so the SL-Class has more braking power available.

The SL-Class stops much shorter than the 911:

For better traction, the SL-Class has larger tires than the 911 (F:255/40R18 & R:285/35R18 vs. F:235/40R18 & R:265/40R18). The SL550’s front tires are larger than the largest tires available on the 911 (255/40R18 vs. 245/35R19).

The SL550’s standard 285/35R18 rear tires provide better handling because they have a lower 35 series profile (height to width ratio) that provides a stiffer sidewall than the 911’s standard 40 series tires.

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the SL-Class can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The 911 doesn’t offer run-flat tires.

The SL-Class has a standard space-saver spare tire so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn’t available on the 911, it requires you to depend on roadside assistance and your vehicle will have to be towed.

The SL-Class offers an available adjustable active suspension system, which counteracts cornering forces actively, limiting body roll and improving handling and stability. Porsche doesn’t offer an active suspension on the 911.

The SL-Class has a standard automatic front and rear load leveling suspension to keep ride height level with a heavy load or when towing. The 911 doesn’t offer a load leveling suspension.

The SL-Class has vehicle speed sensitive variable-assist power steering, for low-effort parking, better control at highway speeds and during hard cornering, and a better feel of the road. The 911 doesn’t offer variable-assist power steering.

For a smoother ride and more stable handling, the SL-Class’ wheelbase is 8.3 inches longer than on the 911 (100.8 inches vs. 92.5 inches).

For better handling and stability, the track (width between the wheels) on the SL-Class is 2.8 inches wider in the front than the average track on the 911.

The SL-Class’ front to rear weight distribution is more even (51% to 49%) than the 911’s (39.8% to 60.2%). This gives the SL-Class more stable handling and braking.

The SL65 AMG handles at .93 G’s, while the 911 Cabriolet pulls only .92 G’s of cornering force in a Car and Driver skidpad test.

The SL-Class’ standard power retractable hardtop allows a seamless transition from an open car, to a completely sealed coupe. The 911 doesn’t offer a retractable hardtop.

The SL-Class has a much larger trunk with its top down than the 911 Cabriolet (7.2 vs. 4.8 cubic feet). The SL-Class has a much larger trunk with its top up than the 911 Cabriolet (10.2 vs. 4.8 cubic feet).

With its convertible body style, valet key and remote trunk release lockout, the SL-Class offers cargo security. The 911’s non-lockable folding seat and non-lockable remote release defeat cargo security.

Unlike the driver-only memory seat and mirrors optional at extra cost in the 911, the SL-Class has standard driver and passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position, seatbelt height, outside mirror angle and climate settings and the front passenger seat also adjusts to the new passenger’s preset preferences.

The SL-Class’ standard easy entry system raises the steering wheel, making it easier for the driver to get in and out. The 911 doesn’t offer an easy entry system.

If the windows are left down on the SL-Class the driver can raise them all using the keyless remote (remote must be aimed at door sensor); on a hot day the driver can lower the windows. The driver of the 911 can’t use the remote to operate the windows.

The SL-Class has a standard automatic headlight on/off feature. When the ignition is on, the headlights automatically turn on at dusk and off after dawn. When the ignition turns off, the headlights turn off after a delay timed to allow you to securely get to your front door. The 911 doesn’t offer automatic headlights.

The SL-Class’ standard dual zone air conditioning allows the driver and front passenger to choose two completely different temperatures so people with different temperature preferences won’t have to compromise. This makes both the driver and front passenger as comfortable as possible. The 911 doesn’t offer dual zone air conditioning.

To keep a safe, consistent following distance, the SL-Class offers an optional Distronic, which alters the speed of the vehicle without driver intervention. This allows the driver to use cruise control more safely without constantly having to disengage it when approaching slower traffic. The 911 doesn’t offer an adaptive cruise control.

The SL-Class’ standard GPS navigation system has a real-time traffic update feature that offers alternative routes to automatically bypass traffic problems. (Service available in a limited number of metro areas.) The 911’s available navigation system doesn’t offer real-time traffic updates.

Wireless connectivity is standard on the SL-Class, connecting the driver and passenger’s cell phones to the vehicle systems. This allows them to use the vehicle’s stereo and hand controls to place calls safely and easily. Porsche doesn’t offer wireless connectivity on the 911.