Used 2014 Acura RLX Sedan

It's not the blind crests, lack of shoulders or even our own unfamiliarity with California State Route 121, also known as Monticello Road here in Napa Valley, that's curtailing our fun. In fact, those things actually enhance the experience. Rather, it's the occasional frost-covered shady patch and the fact that the 2014 Acura RLX's thermometer hovers between 32 and 34 degrees that's got us nervous.

There is no room for error.

Underneath us there's a new all-wheel steering system and a new suspension design. Power is sourced from a direct-injected version of the Accord's 3.5-liter V6 driving a paddle-shifted, rev-matching six-speed transmission.

We settle into a quick but prudent pace that keeps both our confidence and the RLX on solid footing. Push too hard and the big Acura's dampers can't keep up. It's not slow exactly, but we can't avoid the notion that our confidence isn't peaked. Driving the RLX harder than seven-tenths rapidly exceeds its comfort zone. And ours.

What the Acura RLX Isn't
It's possible that Acura's 2014 RLX sedan will be more widely remembered for what it doesn't offer than for what it does. With a transverse power plant driving the front wheels, the RLX (as it's being introduced) flies in the face of conventional midsize luxury layouts, where a longitudinal engine driving either the rear or all four wheels is the status quo.

Later this year, the flagship RLX (a hybrid all-wheel-drive version with electric motors powering the rear wheels) will be available. For now, though, this big Acura is all about the front wheels, and in more ways than one.

But according to Acura representatives and simple reasoning, most buyers aren't purchasing these sedans for the dynamic benefits offered by a rear-drive platform. These sedans aren't, after all, sports cars.

"We learned with the [all-wheel-drive] RL, which was among the best handling cars in the class, that having the best handling car doesn't mean you have the best-selling car," one Honda executive told us.

True. But maybe rear-drive, or at least a rear-drive philosophy, does.

Whether sales are a product of philosophy or function is irrelevant because Acura desperately needs a winner in this class. Last year it sold fewer than 400 RLs, while Lexus and BMW both sent more than 12,000 rear-drive GS 350s and 535is to new homes.

Though Acura isn't keen to predict sales, it's clear that it intends for the 2014 Acura RLX to fix that problem.

But Will the RLX Succeed Where the RL Failed?
Power won't be an issue. Certainly the RLX can't pump iron with the V8-powered competitors in the segment, but this Acura is not underpowered. Though its engine is downsized relative to the outgoing RL's 3.7-liter power plant, the new mill is both more powerful and more efficient. Cranking out 310 horsepower and 272 pound-feet of torque, the engine adds 10 hp and 1 lb-ft of torque to the sedan's résumé.

Variable Cylinder Management (VCM in Honda-speak), in conjunction with direct injection, yields a big bump in efficiency to 20 city/31 highway/24 combined mpg, up from the RL's 17 city/24 highway/20 combined mpg ratings. Contrary to most fuel-saving strategies, Acura lowered the ratios of all six gears and the final drive in the RLX, which should improve acceleration.

There's a Sport mode that increases throttle and transmission response and increases gain on the rear-wheel steering system, though the transmission still won't hold gears at redline.

More puzzling is a lack of optional adjustable or adaptive suspension, which is available on the RLX's biggest competitors. We're big fans of a single suspension calibration, but aren't convinced that the RLX delivers the driving experience luxury buyers want in this segment.

What's Holding the RLX Back?
Three words: Front-wheel drive. Despite being a capable front-drive sedan, there's no escaping front-drive dynamics.

Acura made a 2013 BMW 535i and 2013 Mercedes-Benz E350 available to drive back to back with the RLX on a small handling course where body control, transitional stability and the ability to power out of low-speed corners were priorities. But thanks to the 535i's adjustable damping, this was not the demonstration Acura had hoped for. We preferred the BMW and would put money on it being quicker through the course. The Benz, however, was clearly not as controlled.

It's fair to say that most luxury sedan owners won't subject their cars to such a test. Still, it illustrates the confidence Acura has in its new sedan: confidence which is largely a product of the RLX's Precision All-Wheel Steering (P-AWS). The system is capable of independently controlling the rear wheels so it can execute stability-increasing moves like adding toe-in under heavy braking. Otherwise, its behavior is not unlike previous systems, which steer the rear wheels in phase or out of phase with the fronts depending on a number of factors.

In practice, the effects of rear steering are subtle enough that you'll likely never notice. Certainly it enhances the RLX's handling, but you won't find yourself aware of crabbing across lanes during a freeway lane change. Chassis engineers also use the individual brake application to introduce yaw in certain conditions, which they call Active Handling Assist.

Given its size, the 2014 Acura RLX is a respectable-handling front-driver, but its dynamic abilities aren't game-changing.

Its Looks Are Not Deceiving
Let's face it. The RLX isn't the most striking sedan to ever come out of Japan. Or from anywhere. It's been pegging our forgettable meter since its quiet debut last November at the L.A. auto show, which is ironic given that Acura names "elegant and exclusive style" as the No. 1 priority of luxury sedan customers.

But it is big, inside at least.

It's here that the RLX can make some real claims, like best-in-class interior space. Specifically, and maybe most importantly, that means more rear legroom than its rivals from Audi, BMW, Lexus and Mercedes-Benz. At 112.2 inches the RLX's wheelbase is 2 inches longer than the RL's and is identical to the Lexus GS 350.

There's also less narrowing of the greenhouse above the beltline than these competitors, which results in more shoulder room and head space. Indeed, sit anywhere in the RLX and there's no sense of confinement and visibility is good.

Inspired Interior
Despite its interior dimensions, the 2014 Acura RLX encapsulates its driver and front passenger in a warmly personal space. Its 12-way adjustable seats will suit for long stints and its steering wheel is both small in diameter and thick-rimmed, giving the sense that you're controlling a smaller machine. Materials and assembly quality are befitting a car in this segment.

Instrument panel space is split evenly between a large tachometer on the left and a large speedometer on the right, both of which are typically clear in presentation. Otherwise, Acura's strategy for secondary controls is to allow multiple means to access features, which pays off in keeping the button count reasonable.

The RLX's cabin is among the most serene we've experienced thanks to a set of active engine mounts and active noise cancellation through the audio system. And if you're into that sort of thing, there's an available 14-speaker Krell audio system that even makes Paul Simon sound tolerable. Combined, these amenities make the RLX a solid long-haul choice, as good as or better than its competition.

Genuinely Useful Tech
Perhaps the RLX's most impressive feature is its ability to steer itself. Acura calls this feature the Lane Keeping Assist System, and it does just that. Truth is, the car steers itself for about 10 seconds. Then it wants you to steer again, which seems fair.

A forward-looking camera monitors lane position and keeps lane wanderers from wandering too far. On mildly curving roads it's so subtle and effective that we hope every driver in Los Angeles gets one. In longer corners we noticed the system making small corrections against our input. Still, it's worth it most of the time and easily switched off.

Besides being extremely well-calibrated for the inevitable space-cushion thief, the RLX's Adaptive Cruise Control will now comfortably stop the car and requires only a tap of the throttle or "Resume" button to once again begin tracking back to its preset speed.

The Cost/Benefit Ratio
The 2014 Acura RLX will be available with five packages (Base, Navigation, Technology package, Krell Audio package, Advance package) starting at $49,345 including destination when it hits dealers next month. The car we drove here, outfitted with the Advance Package, will cost $61,345, which will get you a BMW 535i with the Technology and Dynamic Handling packages or a loaded rear-wheel-drive Lexus GS 350.

The full verdict on the RLX won't be in until the all-wheel-drive hybrid version shows up. But even then, the ultimate question facing the RLX isn't whether it can be competitive on features and price, but rather if it can be desirable.

All-wheel drive will help, and the RLX needs all the help it can get.

Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.