2017 Acura RLX Sport Hybrid SH-AWD Advance Review by Carey Russ

Innovative technology combined with luxury comfort

DRIVING DOWN THE ROAD WITH CAREY RUSS

               • SEE ALSO: Acura Research and Buyers Guide

"Sport" and "hybrid" together, in one car? Believe it. Top-level competition cars in endurance racing and Formula 1 now use sophisticated internal combustion plus electric hybrid systems for efficiency and power. Acura's new NSX uses a hybrid system similar to the RLX’s, modified for a mid-engined sports car. Other supercars are headed in the same direction, following their competition relatives.

The RLX’s all-wheel drive system can be thought of as the first version of the system used in its new NSX, with the same basic architecture but for a front-engined sedan instead of a mid-engined sports car. It uses the same 310-horsepower V6 as in the front-wheel drive, non-hybrid version to drive the front wheels. But here it’s assisted by a 47-horsepower electric motor, with a pair of 36-hp electric motors driving the rear wheels on demand. Front power is delivered through a computerized seven-speed dual-clutch transmission, and the whole system works seamlessly via computer control.

Acura’s claim for differentiation in the luxury classes has always been technology. And while that word has been appropriated to mean the latest in electronic gadgetry for entertainment, information, and safety — and plenty of that can be found in the RLX — there is and has been more. Technology for performance, efficiency, and handling ability is also part of the Acura corporate character -- this is the company that brought us the original NSX and Integra GS-R and Type R. The maximum performance for the sake of maximum performance character of those cars is most definitely not missing in action, see the new NSX for an emphatic demonstration. In the RLX Sport Hybrid, performance is covered with the veneer of luxury comfort that is necessary for success today. No demerits for that, as Acura’s sedan flagship RLX competes in the heart of the luxury sedan class, against the best from around the world. And goes one-up on them in the form of the Sport Hybrid SH-AWD model.

As with the regular RLX, the Sport Hybrid SH-AWD model is offered in two trim levels, Technology Package and Advance Package. Changes for 2017 are to standard equipment levels, with AcuraWatch standard in all. No, that’s not something you wear on your wrist. It’s a suite of electronic safety equipment including Adaptive Cruise Control, Collision Mitigation Braking System, Forward Collision Warning, Lane Departure Warning, Lane Keep Assist, Road Departure Mitigation, and Blind Spot Information with Cross Traffic Monitoring.

My test car was the Advance version, so nearly every contemporary electronic comfort, safety, and convenience item was standard equipment. There is likely more circuitry and computing power in this one car than there was used for the entire Mercury through Apollo space program long ago… but it works, and works well. It’s quiet inside, and composed on all roads, and seriously quick when that’s needed or desired. Technology here is not merely for its own sake, it improves performance, economy, and safety. With real-world mileage in the high 20s with more use of fun roads than highways and plenty of performance, the 2017 Acura RLX Sport Hybrid SH-AWD is a 21st Century luxury-performance sedan.

APPEARANCE: Differences between the regular RLX and Sport Hybrid are minimal. The standard wheels are different, and the hybrid has “Hybrid” badges behind the front wheels and an “SH-AWD” badge on the trunk, under the right taillight. Otherwise, it’s quickly recognized as an Acura, size large. Well, more long than bulky, with graceful proportions, the latest iteration of the corporate grille, and LED lighting wherever possible, from the Jewel-Eye headlamp clusters through convenient lighting in the door handle pockets to the taillights.

COMFORT: Inside as well, there are few differences from the regular RLX with the Advance Package. Meaning that it’s a handsome contemporary design with all of the expected luxury comforts, and then some. Also meaning that interior space is closer to that of a full-size rather than mid-size sedan. The most notable difference from the non-hybrid is Acura’s first head-up display, a useful feature. Because of the rear motors and associated hardware trunk space and fuel capacity are decreased, trunk size by three cubic feet and fuel tank by about three gallons — not enough to worry about.

SAFETY: Nearly all existing electronic safety systems are either standard or available in the RLX Sport Hybrid. Its "Advanced Compatibility Engineering™ II unibody structure and full suite of airbags form a solid base for passive passenger protection, while antilock disc brakes with brake assist and electronic brake-force distribution plus regenerative braking and the maneuverability advantages of the torque-vectoring SH-AWD and Agile Handling Assist systems take care of active safety. A multi-angle rearview camera and standard AcuraWatch technology add further convenience and safety.

RIDE AND HANDLING: The RLX's double-wishbone front, multilink rear suspension is tuned in the European luxury manner for a good balance between comfort and cornering ability. Comfort prevails, but maneuverability is good as well. Understeer is reduced and turn-in sharpened by the SH-AWD system (and remember, controllability and maneuverability aren't merely enjoyable aspects of driving, they are important to safety). Steering effort is moderate, never too light or too heavy. Interestingly, the more assertively the SH-AWD RLX is driven, at least to sane street limits, the better it feels. I suspect that the rear torque vectoring gets credit for that. Braking is improved by the electric motors’ regenerative abilities. Because of the extra weight of the hybrid system components, the hybrid weighs about 350 pounds more, but more of that weight is at the rear so it’s very well balanced. At over two tons, it’s hefty — but it’s light on its feet.

PERFORMANCE: The goal in developing the complex Sport Hybrid SH-AWD system was to combine V8-equivalent power with four-cylinder fuel economy. That’s a tough order, and equating performance with the number of cylinders is not necessarily accurate. Still, nearly 30 mpg overall in a roomy two-ton luxury sedan capable of a 0-60 time in the 5.0-second range is impressive, although much use of all of the system power to reach that figure will see mileage drop significantly — as with any vehicle. The 3.5-liter V6 is nearly identical to that used in the regular RLX, and makes 310 horsepower at 6500 rpm and 273 lb-ft of torque at 4700 rpm. Mounted transversely in front, it uses the single overhead cam version of Acura’s i-VTEC valve management system to optimize power and efficiency, with direct fuel injection for further gains in efficiency. Here it’s matched to a seven-speed dual-clutch automated sequential transmission with an integrated electric motor that is used as the starter motor, charges the hybrid system Li-Ion battery, and provides extra power during hard acceleration. Think of the 47 hp (at 3000 rpm) and 109 lb-ft (500-2000 rpm) as an electric turbocharger. There is a noticeable surge when pressing the accelerator hard. It also provides regenerative braking when slowing. The rear wheels are purely electrically-driven, so there is no driveshaft. The two rear motor-generator units assist in acceleration, braking (by regenerative braking), and cornering by differential application of power and/or braking (“torque vectoring”) as determined by the control software and sensors. The SH-AWD system adds about 350 pounds to the RLX’s weight but produces more power, so the hybrid is noticeably quicker than the regular RLX.

Except when cold, the system is smooth and transparent in operation. The dual-clutch transmission, like others of that type, is slow to shift when cold and needs to warm up. Under low acceleration, when the hybrid battery is charged adequately, the car runs for a short while in rear-drive EV mode. Throttle response can be tricky at times, depending on which electric motor does what, and because of three motors worth of regenerative braking, lifting the accelerator can feel like compression from the olden days before emissions equipment. That said, I adapted quickly. Hey, high-tech cars can have character!

CONCLUSIONS: The 2017 Acura RLX Sport Hybrid SH-AWD adds innovative technology to luxury comfort.

SPECIFICATIONS

2017 Acura RLX Sport Hybrid SH-AWD Advance

Base Price $ 65,950

Price As Tested $ 66,890

Engine Type SOHC 24-valve aluminum alloy V6 with i-VTEC valve control and direct fuel injection

Engine Size 3.5 liters / 212 cu. in.

Horsepower 310 @ 6500 rpm

Torque (lb-ft) 273 @ 4700 rpm

Electric Motors:

Front Horsepower 47 @ 3000

Front Torque (lb-ft) 109 @ 500-2000

Rear Motors Horsepower 36 + 36 @ 4000

Rear Motors Torque (lb-ft) 54 + 54 @ 0-2000

Lithium-Ion Battery Pack

System Maximum Combined Horsepower 377

System Maximum Combined Torque 341 lb-ft

Transmission 7-speed DCT

Wheelbase / Length 112.2 in. / 196.1 in.

Curb Weight 4359 lbs.

Pounds Per Horsepower 11.6

Fuel Capacity 15.1 gal.

Fuel Requirement 91 octane unleaded premium gasoline

Tires 245/40 R19 98W m+s Michelin Primacy mxm4

Brakes, front/rear vented disc / solid disc plus regenerative braking

Suspension, front/rear independent double wishbone / independent multilink

Drivetrain Transverse front engine and electric traction motor, separate rear traction motors for all-wheel drive

PERFORMANCE

EPA Fuel Economy - miles per gallon city / highway / observed 29 / 30 / 27

0 to 60 mph est 5 sec

OPTIONS AND CHARGES

Destination Charge $ 940