The RL comes standard with all wheel drive, giving the RL excellent stability and traction in all conditions.With all-wheel drive and electronic stability control, the RL delivers surefooted handling with little chance of a spinout in a slippery turn.This is an easy car to drive well.

Acura's latest Collision Mitigating Braking System warns the RL driver of an impending pileup with audible tones and flashing indicators, then jerks the seat belt, then hits the brakes.This is useful when everyone slams on the brakes at the very moment you're adjusting the radio.The system can reduce the severity of the collision or help the skilled driver avoid it altogether.

Real time traffic reporting is available in major metropolitan areas, providing the driver with traffic conditions and suggesting alternative routes to avoid jams.The system provides weather reports and forecasts for a planned driving route and is integrated into the navigation system.

The 2010 Acura RL boasts significant power increases over pre-2009 models.The RL comes with a 3.7-liter V6, not a V8, and we found its 300 horsepower delivered strong, smooth thrust on the freeway.We found the brakes to be excellent, with a good, firm pedal.

The interior is comfortable and functional, with controls that are easy to operate.Build quality, fit and finish put the Acura RL near the top of its class.Creature comforts abound, including cooling for the front seats and an impressively comprehensive navigation system.

Simply put, anyone shopping for a four-door, five-passenger luxury sedan in this price range should have the Acura RL on the shopping list.

The Technology Package ($3,620) adds a satellite-linked navigation system with voice recognition, rearview camera and Zagat ratings for listed restaurants; three-month trial subscription to real-time traffic and traffic re-routing information for 76 metropolitan areas in the 48-contiguous states and current weather conditions and forecasts not only locally, but also for an intended destination and the selected driving route; active front lighting system; heated and cooled front seats; and upgraded genuine wood interior trim.

Acura-approved accessories include back-up sensors ($530), deck lid spoiler ($485), car cover ($254), nose mask ($162), engine block heater ($66), wheel locks ($81), door edge trim ($39), first aid kit ($30).The All-Season Package ($334) includes floor mats, trunk tray and wheel locks.The Protection Package ($342) includes splash guards, trunk tray and wheel locks.

Safety features include frontal, side impact and curtain airbags; electronic stability system with traction control; antilock brakes, electronic brake-force distribution and brake assist; front seat active head restraints; and tire pressure monitoring system.

The optional Collision Mitigation Braking System Package includes adaptive cruise control and a crash-anticipating system that, depending on a computer's evaluation of the likelihood of the RL colliding with a car ahead, activates one of three levels of visual and audible warnings, automatic pretensioning of the driver's or the driver's and front seat passenger's seatbelts and light or hard braking.The system, which can be turned off, operates only at speeds in excess of 10 miles per hour and only when the speed differential between the RL and the other car is at least 10 miles per hour.

Alongside the bright, pentagonal grille, are compound headlight units slotted into the leading corners of the fenders and wrapping around to a point on a perfect vertical from the front wheelwells, a styling device intended to mask the front overhang and visually pull the front wheels forward.Squarish fog lights are recessed at each end of a secondary air intake extending across the lower fascia split by an raised segment continuing the geometry of the grille through the front bumper.Similar lines flow back from the top of the grille across the hood, ending at the junction with the A-pillars (the side frames of the windshield).

There's a bit of wedge to the side profile, but not as severe as in the Honda Accord, which allows the RL to skirt some of the Accord's uncomfortable resemblance to the Chrysler Sebring sedan.Smooth flanks show the barest trace of a character line picking up just aft of the front wheelwell and running through the recessed, full round side door handles to end at the forward most tip of the taillights.Polished metal strips outline the side windows.A horizontal bump strip along the lower door panels defines the architectural break below which the sheet metal tucks inward toward the brightwork topping the rocker panel.Gently creased bulges give the wheelwells a touch of sportiness.

The hindquarters present something of a bustle look, in large part attributable to a kick up, aerodynamic lift-reducing lip running the width of the trunk lid.Multi-hued taillights bracket the inset cupping the lower trunk opening.A satin finish bar tops the indent housing the license plate.Squashed hexagonal exhaust tips fill spaces carved out of the lower edge of the rear bumper.

Seats are plush without being over-stuffed.The perforated leather breathes enough to keep the seats from being clammy in cold weather or sticky in hot.The cooling capability that comes with the Technology Package should make checking that box automatic in any state where sunny days outnumber cloudy ones.Acura seems finally to have backed down from what to some drivers has been an overly aggressive baseline lumbar configuration.Thigh support could stand improvement, but as it is, it's adequate, although the extendable pad on some of the competition (BMW 5 Series, for example) would be welcome.Rear seats, though, could definitely benefit from deeper bottom cushions.And praise be to the gods of equal treatment, the front passenger seat also comes with height adjustment.

The center stack is well laid out with creature comfort controls.The learning curve for what's where for what function is more like a gentle slope than a cliff face.On BMWs, for example, it's easy to push the wrong button or pressure a knob the wrong direction, but that's not the case on this Acura.In spite of its sophistication, it's not hard to master the navigation system with real-time traffic and weather.That can't be said of the Audi A6 and Mercedes-Benz E-Class.

The RL cabin feels roomy.Roominess is comparable to the others in the class when measured by the tape.Front-seat head room is slightly less but comparable to that of the other cars in the class.Rear-seat head room tops the Lexus, trails the BMW, the Mercedes and the Audi and equals the Infiniti G37x.Leg room, front and rear, comes in about the same, with the RL besting only the Mercedes.Similarly, in hip room, it tops only the Lexus in the rear seat; otherwise, it at best equals but more often trails the others.It has the most shoulder room in the front seat but splits the difference in back, with the BMW and the Mercedes ahead by as much as an inch and the Infiniti, Lexus and Audi behind, also by as much as an inch.

Storage space for stuff is plentiful, with a couple cool twists on old standards.Besides the usual complement of cup holders, magazine pouches and the like, all four doors get map pockets, with the ones on the front doors hinged so they flip out for easy access but snap back against the lower panel for better control of contents.The arm rest covering the center console storage is split longitudinally and hinged on each outboard side, allowing access by either the driver or the front seat passenger without interfering with the other's resting elbow.Even with the bustle-like trunk lid, the RL ranks below average for hauling suitcases, golf bags and gardening supplies; all but the Lexus hold more, with the Mercedes and the Audi the most, and by nearly two full cubic feet.

Like many luxury cars, the RL comes with a keyless start/stop feature, eliminating the need to take your keys out.We find the disadvantages to these systems outweigh their advantages.

The 3.7-liter V6 is rated 300 horsepower at 6300 rpm and 271 pound-feet of torque at 5000 rpm, the former a benefit of its double overhead-cam, 24-valve V6.Fuel economy is an EPA-estimated 16/22 mpg City/Highway.Engine displacement, horsepower and torque put the V6-powered RL solidly in the mainstream of the competition, although the EPA pegs its fuel economy estimates below all but the Mercedes-Benz.

Throttle response is prompt.The power curve felt linear to us save for a barely perceptible surge around 4000 rpm, when the engine's electronics transition between low-speed and high-speed algorithms.Shifts from the five-speed automatic are smooth and certain, whether left to the transmission's computer or managed by the steering wheel mounted paddle shifters.Using the Sequential SportShift can be fun, but we preferred to put the transmission in Drive and let it do the job it does so well, allowing us to concentrate on braking, steering and accelerating.

Body lean is almost non-existent through tight turns and high speed sweepers.Acura's electronically managed all wheel drive system that vectors power to the outside rear wheel in corners contributes to remarkably responsive steering for a car of the RL's mass.Turn in is precise, and transit through a turn, from entrance to apex to exit, especially under power, is delightfully controllable.

The driver can sense the front-wheel-drive bias of the RL.With its rear-wheel-drive architecture and taut suspension, the BMW 535xi feels livelier than the RL, making the BMW more fun to drive.However, the RL is easier to push to the limit in unfamiliar corners.

The Collision Mitigation Braking System and Adaptive Cruise Control systems work together and are impressive.Picture yourself commuting to work in heavy traffic: You glance away for just a moment.Then, for no apparent reason, everyone ahead slams on the brakes.The system senses this is happening and, in stages, warns the driver with audible tones and flashing indicators, then jerks the seat belt, then backs off the throttle, then hits the brakes.It won't completely stop the car, but it will apply the brakes hard enough to induce the ABS.The driver needs to step in and hit the brakes.But this is exactly what your instincts will tell you to do.We found the system works well, meshing perfectly with the driver's instincts, helping avoid an accident.The system can be fooled, however, and we saw one instance when it slammed on the brakes unnecessarily causing an unplanned moment.Of course, the driver can switch the system off.In more typical usage, the adaptive cruise control maintains pre-set following distances behind other cars by adjusting your speed with the throttle and the brakes.

NewCarTestDrive.com correspondent Tom Lankard filed this report based on his test drive of the Acura RL outside Sacramento, California; with reports by Mitch McCullough in Los Angeles.