The Insurance Institute for Highway Safety tests front crash prevention systems. With a score of 6 points, IIHS rates the Collision Prevention Assist Plus in the C-Class Sedan as “Superior.” The IS Series scores only 4 points and is rated only “Advanced.”
The C-Class Sedan’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The IS Series doesn’t offer a driver alert monitor.
Both the C-Class Sedan and the IS Series have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, front parking sensors, available all wheel drive, lane departure warning systems, blind spot warning systems and rearview cameras.
The National Highway Traffic Safety Administration does 35 MPH front crash tests on new vehicles. In this test, results indicate that the Mercedes C-Class Sedan is safer than the Lexus IS Series:
C-Class Sedan |
IS Series |
|
Driver |
||
STARS |
5 Stars |
4 Stars |
HIC |
138 |
274 |
Neck Injury Risk |
24% |
36% |
Neck Stress |
203 lbs. |
339 lbs. |
Leg Forces (l/r) |
421/449 lbs. |
271/602 lbs. |
Passenger |
||
STARS |
4 Stars |
4 Stars |
HIC |
246 |
264 |
Chest Compression |
.6 inches |
.6 inches |
Neck Stress |
147 lbs. |
197 lbs. |
Leg Forces (l/r) |
311/161 lbs. |
426/505 lbs. |
New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.
The National Highway Traffic Safety Administration does side impact tests on new vehicles. In this test, which crashes the vehicle into a flat barrier at 38.5 MPH and into a post at 20 MPH, results indicate that the Mercedes C-Class Sedan is safer than the Lexus IS Series:
C-Class Sedan |
IS Series |
|
Front Seat |
||
STARS |
5 Stars |
5 Stars |
HIC |
76 |
99 |
Abdominal Force |
147 G’s |
193 G’s |
Hip Force |
452 lbs. |
474 lbs. |
Into Pole |
||
STARS |
5 Stars |
5 Stars |
Max Damage Depth |
12 inches |
15 inches |
HIC |
248 |
295 |
Hip Force |
769 lbs. |
806 lbs. |
New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.
There are over 58 percent more Mercedes dealers than there are Lexus dealers, which makes it much easier should you ever need service under the C-Class Sedan’s warranty.
The C-Class Sedan has more powerful engines than the IS Series:
Horsepower |
Torque |
|
C300 Sedan 2.0 turbo 4 cyl. |
241 HP |
273 lbs.-ft. |
C450 AMG 3.0 turbo V6 |
362 HP |
384 lbs.-ft. |
IS 200t 2.0 turbo 4 cyl. |
241 HP |
258 lbs.-ft. |
IS 300 3.5 DOHC V6 |
255 HP |
236 lbs.-ft. |
IS 350 3.5 DOHC V6 |
306 HP |
277 lbs.-ft. |
As tested in Car and Driver the C450 AMG is faster than the IS 350:
C-Class Sedan |
IS Series |
|
Zero to 60 MPH |
4.5 sec |
5.6 sec |
Zero to 100 MPH |
11.2 sec |
13.5 sec |
5 to 60 MPH Rolling Start |
5.4 sec |
6.2 sec |
Quarter Mile |
13.1 sec |
14 sec |
Speed in 1/4 Mile |
108 MPH |
102 MPH |
On the EPA test cycle the C-Class Sedan gets better fuel mileage than the IS Series:
C-Class Sedan |
IS Series |
|||
RWD |
C300/Auto |
25 city/34 hwy |
22 city/33 hwy |
200t/Auto |
n/a |
19 city/28 hwy |
350/Auto |
||
AWD |
C300/Auto |
24 city/31 hwy |
19 city/26 hwy |
300/Auto |
C450 AMG/Auto |
21 city/29 hwy |
19 city/26 hwy |
350/Auto |
In heavy traffic or at stoplights the C-Class Sedan’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 IS Series doesn’t offer an automatic engine start/stop system.
For better stopping power the C450 AMG’s front brake rotors are larger than those on the IS Series:
C450 AMG |
IS Series |
|
Front Rotors |
14.2 inches |
13.1 inches |
Rear Rotors |
12.6 inches |
12.2 inches |
The C-Class Sedan stops much shorter than the IS Series:
C-Class Sedan |
IS Series |
||
70 to 0 MPH |
160 feet |
177 feet |
Car and Driver |
60 to 0 MPH |
108 feet |
128 feet |
Motor Trend |
For better ride, handling and brake cooling the C-Class Sedan offers optional 19-inch wheels. The IS Series’ largest wheels are only 18-inches.
Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the C-Class Sedan can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The IS Series doesn’t offer run-flat tires.
The C-Class Sedan has a standard automatic load leveling suspension to keep ride height level with a heavy load or when towing. The IS Series doesn’t offer a load leveling suspension.
The C-Class Sedan’s drift compensation steering can automatically compensate for road conditions which would cause the vehicle to drift from side to side, helping the driver to keep the vehicle straight more easily. The IS Series doesn’t offer drift compensation steering.
For a smoother ride and more stable handling, the C-Class Sedan’s wheelbase is 1.6 inches longer than on the IS Series (111.8 inches vs. 110.2 inches).
For better handling and stability, the track (width between the wheels) on the C-Class Sedan is 2.1 inches wider in the front and .1 inches wider in the rear than the average track on the IS Series.
The C450 AMG 4MATIC handles at .93 G’s, while the IS Series AWD pulls only .81 G’s of cornering force in a Car and Driver skidpad test.
The C300 Sedan 4MATIC executes Motor Trend’s “Figure Eight” maneuver quicker than the IS Series (26.3 seconds @ .7 average G’s vs. 27.1 seconds @ .65 average G’s).
The front grille of the C-Class Sedan uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The IS Series doesn’t offer active grille shutters.
The C-Class Sedan has .2 inches more rear headroom and 3 inches more rear legroom than the IS Series.
The C-Class Sedan has a much larger trunk than the IS Series (12.6 vs. 10.8 cubic feet).
To make loading and unloading groceries and cargo easier when your hands are full, the C-Class Sedan’s trunk can be opened just by kicking your foot under the back bumper, leaving your hands completely free. The C-Class Sedan also offers an optional power trunk, which opens and closes automatically by pressing a button or just by kicking your foot under the back bumper. The IS Series doesn’t offer a power or hands-free opening trunk.
Unlike the driver-only memory system optional at extra cost in the IS Series, the C-Class Sedan offers an optional passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position and outside mirror angle and the front passenger seat also adjusts to the new passenger’s preset preferences.
The C-Class Sedan’s standard easy entry system raises the steering wheel and glides the driver’s seat back, making it easier for the driver to get in and out. An easy entry system costs extra on the IS Series.
The C-Class Sedan offers an optional heads-up display which projects speed and navigation instruction readouts in front of the driver’s line of sight, allowing drivers to view information without diverting their eyes from the road. The IS Series doesn’t offer a heads-up display.
The power windows standard on both the C-Class Sedan and the IS Series have locks to prevent small children from operating them. When the lock on the C-Class Sedan is engaged the driver can still operate all of the windows, for instance to close one opened by a child. The IS Series prevents the driver from operating the other windows just as it does the other passengers.
The C-Class Sedan’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 IS Series’ standard manually variable intermittent wipers have to be constantly adjusted.
To help drivers see further while navigating curves, the C-Class Sedan offers optional adaptive headlights to illuminate around corners automatically by reading vehicle speed and steering wheel angle. The IS Series doesn’t offer cornering lights.
The C-Class Sedan’s optional Active Parking Assist can parallel park or back into a parking spot by itself, with the driver only controlling speed with the brake pedal. The IS Series doesn’t offer an automated parking system.
J.D. Power and Associates rated the C-Class Sedan second among compact premium cars in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner’s expectations. The IS Series isn’t in the top three.
Strategic Vision rates overall owner satisfaction with vehicle quality. The Mercedes C-Class Sedan is ranked above average in the Near-Luxury Car category. The Lexus IS Series is ranked below average.
The C-Class Sedan was chosen as one of Automobile Magazine’s “All Stars” in 2015. The IS Series has never been an “All Star.”
The Mercedes C-Class outsold the Lexus IS Series by 80% during the 2015 model year.
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