2019 Acura RLX vs. 2019 Mercedes S-Class

Detailed Review, Specifications & Comparison

Your buying experience includes...

business_centerProfessional Staff
account_balanceSimple Financing
local_gas_stationFull Tank of Gas
local_car_washFree Car Wash


Both the RLX and the S-Class have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras and available around view monitors.

For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, its standard front crash prevention system, and its headlight’s “Acceptable” rating, the Insurance Institute for Highway Safety grants the RLX the rating of “Top Pick” for 2018, a rating granted to only 100 vehicles tested by the IIHS. The S-Class has not been tested, yet.


Acura’s powertrain warranty covers the RLX 2 years and 20,000 miles longer than Mercedes covers the S-Class. Any repair needed on the engine, transmission, axles, joints or driveshafts is fully covered for 6 years or 70,000 miles. Coverage on the S-Class ends after only 4 years or 50,000 miles.


From surveys of all its subscribers, Consumer Reports’ December 2018 Auto Issue reports that Acura vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks Acura 4 places higher in reliability than Mercedes.

Fuel Economy and Range

On the EPA test cycle the RLX Sport Hybrid gets better fuel mileage than the S 450 4MATIC (28 city/29 hwy vs. 18 city/28 hwy).

On the EPA test cycle the RLX gets better fuel mileage than the S-Class:








3.5 SOHC V6

20 city/29 hwy



Sport Hybrid 3.5 V6 Hybrid

28 city/29 hwy




450 3.0 turbo V6

19 city/28 hwy



560 4.0 turbo V8

17 city/27 hwy



AMG 65 6.0 turbo V12

13 city/22 hwy



Maybach 650 6.0 turbo V12

13 city/21 hwy



450 3.0 turbo V6

18 city/28 hwy



560 4.0 turbo V8

17 city/27 hwy



AMG 63 4.0 turbo V8

17 city/26 hwy



Maybach 560 4.0 turbo V8

16 city/25 hwy

To lower fuel costs and make buying fuel easier, the Acura RLX uses regular unleaded gasoline (premium recommended for maximum performance). The S-Class requires premium, which can cost 20 to 55 cents more per gallon.

The RLX has a standard cap-less fueling system. The fuel filler is automatically opened when the fuel nozzle is inserted and automatically closed when it’s removed. This eliminates the need to unscrew and replace the cap and it reduces fuel evaporation, which causes pollution. The S-Class doesn’t offer a cap-less fueling system.


A 10-speed automatic is standard on the Acura RLX V6, for better acceleration and lower engine speed on the highway. Only a nine-speed automatic is available for the S-Class.

The RLX offers a standard sequential manual gearbox (SMG). With no clutch pedal to worry about and a fully automatic mode, an SMG is much more efficient than a conventional automatic but just as easy to drive. The S-Class doesn’t offer an SMG or a conventional manual transmission.

Brakes and Stopping

The RLX stops much shorter than the S-Class:





70 to 0 MPH

166 feet

190 feet

Car and Driver

60 to 0 MPH

112 feet

119 feet

Motor Trend

Tires and Wheels

The RLX’s tires provide better handling because they have a lower 40 series profile (height to width ratio) that provides a stiffer sidewall than the S-Class’ standard 50 series tires.

For better ride, handling and brake cooling the RLX has standard 19-inch wheels. Smaller 18-inch wheels are standard on the S-Class.

The RLX offers an optional 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 S-Class; it requires you to depend on its run-flat tires, which limits mileage and speed before they are repaired. If a run-flat is damaged beyond repair by a road hazard your vehicle will have to be towed. Some models of the S-Class don’t even offer run-flats.

Suspension and Handling

The RLX handles at .84 G’s, while the S-Class pulls only .81 G’s of cornering force in a Car and Driver skidpad test.


The Acura RLX may be more efficient, handle and accelerate better because it weighs about 600 to 650 pounds less than the Mercedes S-Class.

The RLX is 8.8 inches shorter than the S-Class, making the RLX easier to handle, maneuver and park in tight spaces.

The RLX uses computer-generated active noise cancellation to help remove annoying noise and vibration from the passenger compartment, especially at low frequencies. The S-Class doesn’t offer active noise cancellation.

Passenger Space

The RLX has .9 inches more front legroom and 4.7 inches more rear legroom than the S-Class.


To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the RLX has standard extendable sun visors. The S-Class doesn’t offer extendable visors.

Economic Advantages

Insurance will cost less for the RLX owner. The Complete Car Cost Guide estimates that insurance for the RLX will cost $1830 to $14823 less than the S-Class over a five-year period.

IntelliChoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the Acura RLX will be $36871 to $102489 less than for the Mercedes S-Class.

© 1991-2018 Advanta-STAR Automotive Research. All rights reserved.

How much is your car worth?

Get the best value for your car from an Asbury dealership.

Featured Videos