Certified Benz & Beemer Compares 2012 Porsche CAYENNE VS 2012 Mercedes G-Class Near Phoenix, AZ

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2012 Porsche CAYENNE

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2012 Mercedes G-Class

Safety Comparison

The Cayenne has standard child safety locks to prevent children from opening the rear doors. The G-Class doesn’t offer child safety locks.

The Cayenne 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 system also pre-charges the brakes to begin deceleration more quickly. The G-Class doesn't offer a collision warning system.

When descending a steep, off-road slope, the Cayenne’s standard Porsche Hill Control allows you to creep down safely. The G-Class doesn’t offer Porsche Hill Control.

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

The Cayenne’s optional blind spot warning system uses digital cameras monitored by computer to alert the driver to moving objects in the vehicle’s blind spots where the side view mirrors don’t reveal them. The G-Class doesn’t offer a system to reveal objects in the driver's blind spots.

For better protection of the passenger compartment, the Cayenne uses safety cell construction with a three-dimensional high-strength frame that surrounds the passenger compartment. It provides extra impact protection and a sturdy mounting location for door hardware and side impact beams. The G-Class uses a body-on-frame design, which has no frame members above the floor of the vehicle.

The Cayenne’s gas tank is mounted inside the frame rails in front of the rear axle to optimally protect the fuel tank in a collision. The Mercedes G-Class’ gas tank is mounted behind the rear axle, where it is more susceptible to rear collisions.

Both the Cayenne and the G-Class have standard driver and passenger frontal airbags, head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, plastic fuel tanks, four wheel antilock brakes, all wheel drive, traction control and electronic stability systems to prevent skidding.

Warranty Comparison

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

Reliability Comparison

To reliably power the ignition and other systems and to recharge the battery, the Cayenne has a standard 220 amp alternator (190 amp - Cayenne V8). The G-Class’ 150 amp alternator isn’t as powerful.

J.D. Power and Associates’ 2011 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that Porsche vehicles are more reliable than Mercedes vehicles. J.D. Power ranks Porsche fourth in reliability, above the industry average. With 14 more problems per 100 vehicles, Mercedes is ranked 8th.

Engine Comparison

As tested in Motor Trend the Cayenne Turbo is faster than the G55 (automatics tested):



Zero to 30 MPH

1.4 sec

1.6 sec

Zero to 60 MPH

4.3 sec

4.7 sec

Zero to 80 MPH

7.1 sec

7.8 sec

Zero to 100 MPH

10.6 sec

12.5 sec

Quarter Mile

12.8 sec

13.2 sec

Speed in 1/4 Mile

108.9 MPH

103.2 MPH

Fuel Economy and Range Comparison

On the EPA test cycle the Cayenne Hybrid gets better fuel mileage than the G550 (20 city/24 hwy vs. 11 city/15 hwy).

On the EPA test cycle the Cayenne gets better fuel mileage than the G-Class:





16 city/23 hwy



16 city/22 hwy

11 city/15 hwy


Turbo V8/Auto

15 city/22 hwy

11 city/13 hwy


Regenerative brakes improve the Cayenne Hybrid’s fuel efficiency by converting inertia back into energy instead of wasting it. The G-Class doesn’t offer a regenerative braking system.

In heavy traffic or at stoplights the Cayenne Automatic’s engine automatically turns off when the vehicle is stopped, saving fuel and reducing pollution. The engine is automatically restarted when the driver gets ready to move again. (Start/Stop isn’t accounted in present EPA fuel mileage tests.) The G-Class doesn’t offer an automatic engine start/stop system.

The Cayenne’s optional fuel tank has 1 gallons more fuel capacity than the G-Class (26.4 vs. 25.4 gallons).

Brakes and Stopping Comparison

For better stopping power the Cayenne’s brake rotors are larger than those on the G-Class:


Cayenne Turbo



Front Rotors

13.8 inches

16.14 inches

12.3 inches

13.8 inches

Rear Rotors

13 inches

14.57 inches

10.7 inches

13 inches

The Cayenne’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs standard on the G550 are solid, not vented.

The Cayenne 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 G-Class doesn’t offer ceramic brake rotors.

The Cayenne stops much shorter than the G-Class:



60 to 0 MPH

106 feet

129 feet

Motor Trend

Tires and Wheels Comparison

The Cayenne’s standard tires provide better handling because they have a lower 55 series profile (height to width ratio) that provides a stiffer sidewall than the G550’s standard 60 series tires. The Cayenne’s optional tires have a lower 50 series profile than the G55’s 55 series tires.

For better ride, handling and brake cooling the Cayenne offers optional 21 inch wheels. The G-Class’ largest wheels are only 19 inches.

Suspension and Handling Comparison

The Porsche Cayenne’s independent front suspension is much lighter than the Mercedes G-Class’ solid front axle, which allows the Cayenne’s wheels to react more quickly and accurately to the road’s surface, improving both ride and handling.

For superior ride and handling, the Porsche Cayenne has fully independent front and rear suspensions. An independent suspension allows the wheels to follow the road at the best angle for gripping the pavement, without compromising ride comfort. The Mercedes G-Class has a solid rear axle, with a non-independent rear suspension.

The Cayenne has standard front and rear stabilizer bars, which help keep the Cayenne flat and controlled during cornering. The G-Class’ suspension doesn’t offer a rear stabilizer bar.

The Cayenne (except Hybrid) offers active sway bars, which help keep it flat and controlled during cornering, but disconnect at lower speeds to smooth the ride and offer greater off-road suspension articulation. This helps keep the tires glued to the road on-road and off. The G-Class doesn’t offer an active sway bar system.

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

The Cayenne 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 or off-road. The G-Class’ suspension doesn’t offer adjustable shock absorbers.

For much better steering response and tighter handling the Cayenne has rack and pinion steering, like Formula race cars, instead of the recirculating-ball type steering of the G-Class.

The Cayenne offers optional 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 G-Class doesn’t offer variable-assist power steering.

For a smoother ride and more stable handling, the Cayenne’s wheelbase is 1.8 inches longer than on the G-Class (114 inches vs. 112.2 inches).

For better handling and stability, the track (width between the wheels) on the Cayenne is 5.6 inches wider in the front and 6.1 inches wider in the rear than on the G-Class.

The Cayenne Turbo handles at .95 G’s, while the G55 pulls only .65 G’s of cornering force in a Motor Trend skidpad test.

For better maneuverability, the Cayenne’s turning circle is 4.4 feet tighter than the G-Class’ (39.1 feet vs. 43.5 feet).

For greater off-road capability the Cayenne has a greater minimum ground clearance than the G-Class (8.7 vs. 8.1 inches), allowing the Cayenne to travel over rougher terrain without being stopped or damaged. The Cayenne Turbo’s minimum ground clearance is 2.65 inches higher than on the G-Class (10.75 vs. 8.1 inches).

Chassis Comparison

The Porsche Cayenne may be more efficient, handle and accelerate better because it weighs about 800 to 1200 pounds less than the Mercedes G-Class.

The Cayenne is 8.6 inches shorter in height than the G-Class, making the Cayenne much easier to wash and garage and drive (lower center of gravity).

Unibody construction makes the Cayenne’s chassis much stiffer, which contributes to better handling, and enables softer springs to be used for a better ride. Unibody construction’s stiffness also contributes to better durability and less body squeaks and rattles. The G-Class doesn’t use unibody construction, but a body-on-frame design.

The design of the Porsche Cayenne amounts to more than styling. The Cayenne has an aerodynamic coefficient of drag of .35 Cd. That is significantly lower than the G-Class (.54). A more efficient exterior helps keep the interior quieter and helps the Cayenne get better fuel mileage.

For excellent aerodynamics, the Cayenne has standard flush composite headlights. The G-Class has recessed headlights that spoil its aerodynamic shape and create extra drag.

Passenger Space Comparison

The Cayenne has 4.8 inches more front shoulder room and .4 inches more rear shoulder room than the G-Class.

For enhanced passenger comfort on long trips the Cayenne’s rear seats recline. The G-Class’ rear seats don’t recline.

Cargo Capacity Comparison

The Cayenne’s liftgate lifts up in one piece, completely out of the way of loading and unloading, while sheltering the cargo loading area. The G-Class’ swing out door blocks loading from the driver’s side.

The Cayenne’s rear cargo window opens separately from the rest of the liftgate door to allow quicker loading of small packages. The G-Class’ rear cargo window doesn’t open.

To make loading and unloading groceries and cargo easier, especially for short adults or children, the Cayenne has a standard power rear liftgate, which opens and closes completely automatically by pressing a button on the key fob. The G-Class doesn’t offer a power left swing out.

Ergonomics Comparison

The Cayenne’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 G-Class does not have an oil pressure gauge.

The Cayenne’s front and rear power windows all open or close with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside of the car. The G-Class’ power windows’ switches have to be held the entire time to close them fully.

Porsche Entry and Drive optional on the Cayenne allows the driver to unlock the doors, cargo door 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 G-Class doesn’t offer an advanced key system.

While driving with high beams on, sensitive light sensors available for the Cayenne detect other vehicles which could be blinded and automatically switch to low beams. The G-Class doesn’t offer automatic dimming high beams.

The G-Class’ cornering lamps activate a lamp on the front corner when the turn signal is activated. The Cayenne’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.

To better shield the driver and front passenger’s vision, the Cayenne has standard dual-element sun visors that can block glare from two directions simultaneously. The G-Class doesn’t offer secondary sun visors.

To shield the driver’s vision over a larger portion of the windshield and side window, the Cayenne has a standard extendable sun visor. The G-Class doesn’t offer extendable visors.

The Cayenne’s standard power mirror controls are mounted on the armrest for easy access. The G-Class’ standard power mirror controls are on the dash, hidden behind the steering wheel, where they are awkward to manipulate.

The Cayenne has a standard center folding armrest for the rear passengers. A center armrest helps make rear passengers more comfortable. The G-Class doesn’t offer a rear seat center armrest.

To keep a safe, consistent following distance, the Cayenne offers an optional Adaptive Cruise Control, 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 G-Class doesn’t offer an adaptive cruise control.

To help keep rear passengers entertained, the Cayenne offers optional rear seat controls for the radio which can play a separate audio source. The G-Class doesn’t offer rear seat audio controls.

Economic Advantages Comparison

The headlight lenses on the Cayenne are made of plastic to be lighter, more resistant to damage and less expensive to replace than the glass headlight lenses on the G-Class.

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