Certified Benz & Beemer Compares 2008 Mercedes Benz S-Class VS 2008 Acura RL Near Scottsdale, AZ

For enhanced safety, the front and rear seat shoulder belts of the Mercedes S Class have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Acura RL doesn’t offer pretensioners for the rear seat belts.

For enhanced safety, the front and rear seat shoulder belts of the Mercedes S 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 Acura RL has only front height-adjustable seat belts.

The S Class has standard whiplash protection, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the whiplash protection system moves the headrests forward to prevent neck and spine injuries. The RL doesn’t offer a whiplash protection system.

An active infrared night vision system optional on the S Class helps the driver to more easily detect people, animals or other objects in front of the vehicle at night. Using an infrared camera and near-infrared lights to detect heat, the system then displays the image on a monitor in the dashboard. The RL doesn’t offer a night vision system.

The S Class has standard Tele Aid, 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 RL doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies.

Both the S Class and the RL have standard driver and passenger frontal airbags, front side-impact airbags, head airbags, height-adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding and available all-wheel drive.

There are over 20 percent more Mercedes dealers than there are Acura dealers, which makes it easier to get service under the S Class’ warranty.

The camshafts in the S Class’ engine are driven by a hardened steel chain, with no maintenance needs. The RL’s camshafts are driven by a rubber belt, which eventually needs to be replaced. If the RL’s cam drive belt breaks the engine could be severely damaged when the pistons hit the opened valves.

J.D. Power and Associates rated the S Class first among large premium cars in their 2007 Initial Quality Study. The RL isn’t in the top three in its category.

J.D. Power and Associates’ 2005 Initial Quality Study of new car owners surveyed provide the statistics that show that Mercedes vehicles are better in initial quality than Acura vehicles. J.D. Power ranks Mercedes fifth in initial quality, above the industry average. With 19 more problems per 100 vehicles, Acura is ranked 17th, below the industry average.

The S550’s standard 5.5 DOHC V8 produces 92 more horsepower (382 vs. 290) and 135 lbs.-ft. more torque (391 vs. 256) than the RL’s 3.5 SOHC V6. The S600’s standard 5.5 turbo V12 produces 220 more horsepower (510 vs. 290) and 356 lbs.-ft. more torque (612 vs. 256) than the RL’s 3.5 SOHC V6. The S63’s standard 6.2 DOHC V8 produces 228 more horsepower (518 vs. 290) and 209 lbs.-ft. more torque (465 vs. 256) than the RL’s 3.5 SOHC V6. The S65’s standard 6.0 turbo V12 produces 314 more horsepower (604 vs. 290) and 482 lbs.-ft. more torque (738 vs. 256) than the RL’s 3.5 SOHC V6.

As tested in Car and Driver the Mercedes S Class is faster than the Acura RL:

For more instantaneous acceleration and better engine flexibility in any gear, the S Class’ engines produce their peak torque at lower RPM’s than the RL:

The S Class has 4.4 gallons more fuel capacity than the RL (23.8 vs. 19.4 gallons), for longer range between fill-ups.

For better stopping power the S Class’ front brake rotors are larger than those on the RL:

The S Class stops much shorter than the RL:

For better traction, the S Class has larger standard tires than the RL (255/45R18 vs. 245/50R17). The S Class’ optional tires are larger than the largest tires available on the RL (F:255/40R19 & R:275/40R19 vs. 245/50R17).

The S550’s standard tires provide better handling because they have a lower 45 series profile (height to width ratio), which provides a stiffer sidewall than the RL’s standard 50 series tires. The S63/65’s tires have a lower 35 series profile than the RL’s 50 series tires.

For better ride, handling and brake cooling the S550 has standard 18-inch wheels. Smaller 17-inch wheels are standard on the RL. The S63/65’s 20-inch wheels are larger than the 18-inch wheels optional on the RL.

The front and rear suspension of the S Class uses air springs for a smoother, controlled ride than the RL, which uses coil springs. Air springs maintain proper ride height and ride more smoothly.

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

The S Class offers an optional continuously variable suspension system. Using sensors on steering angle, speed and other driver inputs, the shocks soften to improve ride, or stiffen when appropriate to aid handling on tricky roads. The RL’s suspension doesn’t offer adjustable shock absorbers.

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

For a smoother ride and more stable handling, the S Class’ wheelbase is 14.4 inches longer than on the RL (124.6 inches vs. 110.2 inches).

For better handling and stability, the track (width between the wheels) on the S Class is 1.2 inches wider in the front and .8 inches wider in the rear than on the RL.

The S Class’ front to rear weight distribution is more even (51.5% to 48.5%) than the RL’s (58% to 42%). This gives the S Class more stable handling and braking.

The S65 handles at .90 G’s, while the RL pulls only .86 G’s of cornering force in a Car and Driver skidpad test.

As tested by AutoWeek, the interior of the S600 is quieter than the RL:

Because it has more passenger and cargo room, the S Class is rated a Large car by the EPA, while the RL is rated a Mid-size.

The S Class has 10.3 cubic feet more passenger volume than the RL (109.4 vs. 99.1).

The S Class has 5.7 inches more front hip room, .6 inches more front shoulder room, 1.3 inches more rear headroom, 6 inches more rear legroom, 6.9 inches more rear hip room and 2.6 inches more rear shoulder room than the RL.

For enhanced passenger comfort on long trips the S Class’ available rear seats recline. The RL’s rear seats don’t recline.

The S Class has a much larger trunk than the RL (16.3 vs. 13.1 cubic feet).

A low lift-over trunk design makes loading and unloading the S Class easier. The S Class’ trunk lift-over height is 27.5 inches, while the RL’s liftover is 30 inches.

Unlike the driver-only memory system in the RL, the S 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, climate settings and radio stations and the front passenger seat also adjusts to the new passenger’s preset preferences.

The power windows standard on both the S Class and the RL have locks to prevent small children from operating them. When the lock on the S Class is engaged the driver can still operate all of the windows, for instance to close one opened by a child. The RL prevents the driver from operating the other windows just as it does the other passengers.

If the windows are left down on the S 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 RL can only operate the windows from inside the vehicle, with the ignition on.

The RL’s power locks don’t automatically lock the doors. The S Class’ standard power locks automatically lock the doors when a certain speed is reached. This is an important feature for occupant safety. Locked doors are proven to open less often in collisions, and they are also effective in preventing crime at traffic lights. (The power lock’s automatic feature may have to be activated by your dealer.)

The S Class’ 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 RL’s intermittent wipers change speed with vehicle speed, but can’t turn on and off or change speed based on changing rainfall.

Heated windshield washer nozzles are standard on the S Class to prevent washer fluid and nozzles from freezing and help continue to keep the windshield clear in sub-freezing temperatures. The RL doesn’t offer heated windshield washer nozzles.

In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The S Class has standard headlight washers to keep headlight output high. The RL doesn’t offer headlight washers.

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

The S Class has standard automatic dimming rear and side view mirrors which automatically darken quickly when headlights shine on them, keeping following vehicles from blinding or distracting the driver. The RL has an automatic rear view mirror, but its side mirrors don’t dim.

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

The S Class will cost the buyer less in the long run because of its superior resale value. Kiplinger’s estimates that the S Class will retain a greater percentage of its original price after two and four years than the RL.