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Acura RLX Sport Hybrid conquers the turns, and the pump (hands-on)

Twin rear-drive motors help Acura's high-tech model handle in the turns, while its hybrid drivetrain scores an average 30 mpg.

Wayne Cunningham Managing Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
Wayne Cunningham
7 min read

2014 Acura RLX Sport Hybrid
The new RLX Sport Hybrid gets more power, and better fuel economy, than the standard RLX model. Wayne Cunningham/CNET

With its flagship sedans, formerly the RL and now the RLX, Acura has struggled to maintain parity with the likes of rivals Lexus and Mercedes-Benz. That difficulty had to do with Acura's insistence on a front-wheel-drive platform fitted with a V-6 engine, pitted against rear-wheel-drive V-8 cars, and relative size. Acura's flagship sedans tended to compare with second-tier cars from the competition. Despite the large cabin and impressive Krell audio system, Acura stuck to its guns with the 2014 Acura RLX model.

The 2014 Acura RLX Sport Hybrid, however, sets itself apart through high-tech power and economy.

Sport and hybrid are two words that don't generally sit together comfortably in the automotive world. The underpowered Lexus CT 200h and Honda CR-Z attempted the combination, but only the Porsche Cayenne Hybrid really hit the mark. On an early winter day, Acura gave me the opportunity to see if the 2014 RLX Sport Hybrid lived up to its extended name.

To give you an up-front precis, the hybrid performance was excellent, and the sport enjoyable.

Acura turns to hybrid drivetrain for new RLX flagship sedan (pictures)

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Three motors and an engine
Acura can claim some real innovation with the RLX Sport Hybrid's drivetrain, as it features a 3.5-liter direct-injected V-6 engine driving the front wheels, like the standard RLX, then three electric motors and a seven-speed dual-clutch transmission rounding out the formula. One of the motors adds thrust to the front wheels, and the other two independently drive the rear wheels. That system is similar to what Acura has been developing for its new NSX sports car, although reversed, with the twin motors driving the front wheels and the gasoline engine at the rear.

By itself, the V-6 engine generates 310 horsepower and 273 pound-feet of torque. In the standard RLX, that's all you get. The front motor in the RLX Sport Hybrid, situated between the engine and seven-speed dual-clutch transmission, mixes in its 35 kilowatts. What Acura calls the Twin Motor Unit sits between the rear wheels, putting 27 kilowatts of power on each side. Acura specs total system output at 377 horsepower and a matched 377 pound-feet of torque.

Even with that big power output and an extra 350 pounds over the standard RLX, the RLX Sport Hybrid earns EPA fuel economy of 28 mpg city and 32 mpg highway.

2014 Acura RLX Sport Hybrid
Buttons take the place of a conventional shifter. Wayne Cunningham/CNET

Settling into the cushy driver's seat, two elements I hadn't seen in the standard RLX stood out: a head-up display showed power flow and other graphical information, and a set of buttons took the place of a conventional shifter.

I'm all for doing away with shifters in modern automatics, as these legacy pieces of hardware merely engage electronics, a job just as well done with buttons or dials. The RLX Sport Hybrid's drive buttons were big and easy to comprehend, and the only time I had to look at the console was when I wanted to put the car in Park. With familiarity, using the buttons would become second nature. As part of its sportiness, the car also featured steering-wheel-mounted paddles for manually shifting the transmission. And along with the P, R, N, and D buttons was a Sport button, affecting transmission and throttle response.

When I tipped in the throttle, the RLX Sport Hybrid rolled out onto San Francisco city streets fully under electric power, emphasizing the gas-saving nature of the car. And I appreciated that Acura did not bother with an Eco mode; when it's not in Sport, Eco is the default.

Fiddling around with the steering-wheel-mounted controls for the HUD, I found a tachometer graphic, not so useful while suffering through city traffic, but it would prove its worth later in the day.

The electric power steering was tuned for luxury lightness, making it easy to spin the wheel around for parking maneuvers or a quick lane change. The luxury feel was enhanced with a couple of sound-insulation measures. Acura uses laminated glass for the windows and passive acoustic dampers in the wheels, both of which knocked down outside noise to a low murmur. The noise control set the stage for the Krell audio system, which makes use of 14 speakers to deliver very balanced music reproduction with a slightly fat sound, similar to that of classic Fender guitars.

Two displays and a dial
Acura's hard-drive-based navigation system comes standard in the RLX Sport Hybrid, featuring live traffic along with plan and perspective map views. The car also suffers from Acura's new cabin tech interface, which I haven't liked in any of my testing. The interface consists of an LCD at the top of the dashboard, a touch screen within easy reach of the driver, and another set of physical controls below the touch screen. This oddball system duplicates some controls and diverges on others. As one example, when I cabled my iPhone to the car, the touch screen only let me browse through albums in a Cover Flow format, while the physical controls let me browse a traditional music library interface on the upper LCD.

2014 Acura RLX Sport Hybrid
This dual display and dial setup makes controlling cabin tech difficult. Wayne Cunningham/CNET

Acura should have done away with the physical controls, and configured the touch screen, which has haptic feedback, to control all the navigation, audio, and phone functions shown on the upper LCD.

The RLX Sport Hybrid featured the usual audio sources, adding Pandora and Aha Radio app integration to the mix. One thing that surprised me, and which I need to explore further, was that the cabin tech interface seemed to let me choose albums, artists, and tracks from a Bluetooth-connected iPhone. That is a capability I had not previously seen through a Bluetooth connection.

Somewhat mitigating the luxury character of the car, a small pothole on a city street sent a big jolt into the cabin of the RLX Sport Hybrid. Acura cautioned me that I would be driving a preproduction model, but said that the driving dynamics were all production-ready. The car uses a fixed suspension, a fairly typical configuration for higher-end vehicles, and the tires were not particularly low-profile, so I was surprised by the jolt, but I didn't encounter any repeats of that severity.

Throughout my city driving, the engine tended to kick in when I took off from a stop, but it was barely noticeable, muffled by good vibration and sound deadening. When I watched the tach, I could see the engine shutting down as the car reached a steady speed, giving good hybrid performance.

The real value of this hybrid system came among the tight turns on Highway 1 north of San Francisco. Acura uses the Twin Motor Unit at the rear wheels to enact torque vectoring, twisting the outside rear wheel in a turn harder than the inside wheel, and sometimes even applying negative torque to the inside wheel. Getting on the throttle and pushing the car hard in a turn, I could feel this system bringing the back end of the car around, helping negotiate the turn.

This torque vectoring is a very cool and unique feature, and involved some insanely complicated development from Acura.

The seven-speed dual-clutch transmission also did its part to justify the car's Sport label. Using the paddles, it gave me quick, snappy gear shifts. Leaving it in automatic Sport mode, it downshifted when I hit the brakes ahead of a turn to keep the engine power up.

2014 Acura RLX Sport Hybrid
The RLX Sport Hybrid shows some handling chops, but doesn't thrill with acceleration. Wayne Cunningham/CNET

However, holding the RLX Sport Hybrid back from competing with the AMGs and Ms of the world were its somewhat floaty suspension and the anemic power delivery from the drivetrain. That latter piece will be something of concern for those anticipating the upcoming NSX model. Acura remained vague about the actual zero-to-60 mph time in its presentation and materials, only seeming to put it on par with the BMW 535i.

When I stepped into the throttle, the engine gave forth an enjoyable growl but the actual progress forward felt sedate. I wasn't pinned to my seat back and I didn't feel like there was an elephant sitting on my chest. The RLX Sport Hybrid happily took off down the road with very little drama, the dual 377 power specifications making themselves little felt.

Seven-day driver
Only a few Type A personalities really look for hard-core aggressive performance from a large sedan, and their needs are well taken care of by BMW, Mercedes-Benz, and Audi. The 2014 Acura RLX Sport Hybrid's appeal comes more in its high-tech features and fine fuel economy than in any track day fantasies. The complex drive system should certainly help out in slippery conditions, and there is little arguing with a 30 mpg average for a large sedan. The available power works well enough for average traffic conditions and roads.

Acura includes a host of driver assistance features in models equipped with the Advance package, such as adaptive cruise control, a blind-spot monitor, and lane-departure warning. But none of these features breaks new ground.

As a luxury roller, the ample space in the RLX Sport Hybrid's cabin is very notable. A solid package of cabin tech features incorporates some rudimentary app integration, while the Krell audio system remains a highlight. However, I could never see myself growing to like the oddly complicated cabin tech interface.

The 2014 Acura RLX Sport Hybrid will be hitting showrooms by next summer. Pricing is not available yet, although Acura suggested it would fall somewhere between $55,000 and $65,000.