Son's Automotive Group Compares 2015 Mercedes Benz M-Class VS 2015 Cadillac SRX Near Buford, GA

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2015 Mercedes Benz M-Class

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2015 Mercedes Benz M-Class

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2015 Cadillac SRX

Safety Comparison

For enhanced safety, the front and rear seat shoulder belts of the Mercedes M-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 Cadillac SRX doesn’t offer pretensioners for the rear seat belts.

The M-Class’ front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The SRX doesn’t offer pre-crash pretensioners.

An active infrared night vision system optional on the M-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 SRX doesn’t offer a night vision system.

The M-Class offers an optional Surround View System to allow the driver to see objects all around the vehicle on a screen. The SRX only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.

The M-Class’ 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 SRX doesn’t offer a driver alert monitor.

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

The National Highway Traffic Safety Administration does 35 MPH front crash tests on new vehicles. In this test, results indicate that the Mercedes M-Class is safer than the Cadillac SRX:




5 Stars

4 Stars



5 Stars

5 Stars




Neck Injury Risk



Neck Stress

336 lbs.

396 lbs.



5 Stars

4 Stars




Neck Injury Risk



Neck Stress

154 lbs.

203 lbs.

Neck Compression

115 lbs.

131 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 M-Class is safer than the Cadillac SRX:



Front Seat


5 Stars

5 Stars

Abdominal Force

150 G’s

168 G’s

Hip Force

256 lbs.

370 lbs.

Rear Seat


5 Stars

5 Stars




Spine Acceleration

29 G’s

43 G’s

Hip Force

427 lbs.

498 lbs.

Into Pole


5 Stars

4 Stars

Max Damage Depth

15 inches

16 inches




Spine Acceleration

29 G’s

60 G’s

Hip Force

593 lbs.

901 lbs.

New test not comparable to pre-2011 test results. More stars = Better. Lower test results = Better.

For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and its standard front crash prevention system, the Insurance Institute for Highway Safety grants the M-Class its highest rating: “Top Pick Plus” for 2014, a rating granted to only 48 vehicles tested by the IIHS. The SRX has not been fully tested, yet.

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 Mercedes M-Class V6 Gas’ reliability will be 6% better than the SRX.

J.D. Power and Associates’ 2014 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that Mercedes vehicles are more reliable than Cadillac vehicles. J.D. Power ranks Mercedes second in reliability, above the industry average. With 3 more problems per 100 vehicles, Cadillac is ranked third.

Engine Comparison

The ML350’s standard 3.5 DOHC V6 produces 8 lbs.-ft. more torque (273 vs. 265) than the SRX’s 3.6 DOHC V6. The ML400’s standard 3.0 turbo V6 produces 21 more horsepower (329 vs. 308) and 89 lbs.-ft. more torque (354 vs. 265) than the SRX’s 3.6 DOHC V6.

The M-Class’ 2.1 turbo diesel produces 104 lbs.-ft. more torque (369 vs. 265) than the SRX’s 3.6 DOHC V6.

As tested in Consumer Reports the ML350 is faster than the Cadillac SRX:



Zero to 30 MPH

2.5 sec

2.7 sec

Zero to 60 MPH

6.8 sec

7.1 sec

45 to 65 MPH Passing

4.9 sec

5 sec

Quarter Mile

15.2 sec

15.7 sec

Speed in 1/4 Mile

93 MPH

90.6 MPH

Fuel Economy and Range Comparison

On the EPA test cycle the ML350 RWD gets better fuel mileage than the SRX FWD (18 city/24 hwy vs. 17 city/24 hwy).

In heavy traffic or at stoplights the M-Class (except 350)’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 SRX doesn’t offer an automatic engine start/stop system.

The M-Class has 3.6 gallons more fuel capacity than the SRX (24.6 vs. 21 gallons), for longer range between fill-ups.

Brakes and Stopping Comparison

For better stopping power the ML400’s brake rotors are larger than those on the SRX:



Front Rotors

14.8 inches

13.6 inches

Rear Rotors

13 inches

12.4 inches

The M-Class stops shorter than the SRX:



60 to 0 MPH

121 feet

128 feet

Motor Trend

Tires and Wheels Comparison

For better traction, the M-Class has larger standard tires than the SRX (255/50R19 vs. 235/65R18). The M-Class’ optional tires are larger than the largest tires available on the SRX (265/45R20 vs. 235/65R18).

The ML250 BlueTEC’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 SRX’s standard 65 series tires. The M-Class’ optional tires have a lower 45 series profile than the SRX’s optional 55 series tires.

Suspension and Handling Comparison

The M-Class has standard front and rear gas-charged shocks for better control over choppy roads. The SRX’s suspension doesn’t offer gas-charged shocks.

The M-Class 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 SRX doesn’t offer an active sway bar system.

The M-Class has a standard automatic load leveling suspension to keep ride height level with a heavy load or when towing. The SRX doesn’t offer a load leveling suspension.

For a smoother ride and more stable handling, the M-Class’ wheelbase is 4.3 inches longer than on the SRX (114.8 inches vs. 110.5 inches).

For better handling and stability, the track (width between the wheels) on the M-Class is 1.1 inches wider in the front and 2.2 inches wider in the rear than on the SRX.

The M-Class 4MATIC handles at .81 G’s, while the SRX 4 pulls only .80 G’s of cornering force in a Car and Driver skidpad test.

For better maneuverability, the M-Class’ turning circle is 1.6 feet tighter than the SRX’s (38.7 feet vs. 40.3 feet).

For greater off-road capability the M-Class Airmatic has a 4.2 inches greater minimum ground clearance than the SRX (11.2 vs. 7 inches), allowing the M-Class to travel over rougher terrain without being stopped or damaged.

Passenger Space Comparison

The M-Class has .2 inches more front shoulder room, .1 inches more rear headroom, 2.1 inches more rear legroom and 2.1 inches more rear shoulder room than the SRX.

Cargo Capacity Comparison

The M-Class has a much larger cargo area with its rear seat up than the SRX with its rear seat up (38.2 vs. 29.8 cubic feet). The M-Class has a much larger cargo area with its rear seat folded than the SRX with its rear seat folded (80.3 vs. 61.1 cubic feet).

A low lift-over cargo hatch design makes loading and unloading the M-Class easier. The M-Class’ cargo hatch lift-over height is 29 inches, while the SRX’s liftover is 30.1 inches.

Ergonomics Comparison

Unlike the driver-only memory system optional in the SRX, the M-Class offers an optional driver and 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 M-Class’ 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 SRX’s rear power window switches have to be held the entire time to close them fully.

If the windows are left down on the M-Class the driver can raise them all using the key in the outside lock cylinder or the keyless remote; on a hot day the driver can lower the windows. The driver of the SRX can only raise the windows from inside the vehicle, with the ignition on.

The M-Class has a standard locking fuel door with a remote release located convenient to the driver. A locking fuel door helps prevent vandalism, such as sugar in the tank and fuel theft. The SRX doesn’t offer a locking fuel door.

The M-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 SRX’s standard manually variable intermittent wipers have to be constantly adjusted.

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

The M-Class offers an optional 115-volt a/c outlet in the cargo area, allowing you to recharge a laptop or run small household appliances without special adapters that can break or get misplaced. The SRX doesn’t offer a house-current electrical outlet.

The M-Class’ 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 SRX doesn’t offer an automated parking system.

Economic Advantages Comparison

According to The Car Book by Jack Gillis, the M-Class is less expensive to operate than the SRX because typical repairs cost less on the M-Class than the SRX, including $24 less for an alternator.

Recommendations Comparison

Consumer Reports® recommends the Mercedes M-Class, based on reliability, safety and performance. The Cadillac SRX isn't recommended.

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