The 4.6-liter V8 can propel the LS 460 from 0-60 mph in a mere 5.4 seconds, according to Lexus, yet it gets an EPA-rated 24 mpg Highway.The eight-speed automatic is super smooth and plays a big role in the fuel-economy story.The electrically powered steering system adjusts according to speed.The ride quality and handling are exemplary.It doesn't get any smoother than the Lexus LS and it meets every expectation for refinement and luxury.

The Lexus LS 600h L employs a hybrid powertrain using a 5.0-liter V8 and electric motors rated at 438 total system horsepower.The LS 600h L delivers EPA fuel economy ratings of 20/22 mpg City/Highway.The LS 600h L is certified as a Super Ultra-Low Emission Vehicle (SULEV).The LS 600h L comes with all-wheel drive and rides on the long wheelbase.

For 2009, all-wheel drive is available on the LS 460 and LS 460 L for enhanced traction and stability.The all-wheel-drive system features a Torsen limited-slip center differential to distribute torque between the front and rear tires.Normally, the front-to-rear torque split is set at 40:60 but it can vary between 30:70 and 50:50 depending on driving conditions.

The LS is packed with luxury and bristles with technology.The Lexus LS 460 was the first car in the world with a computer-controlled eight-speed automatic transmission.The LS 460 L is a long-wheelbase version that offers reclining heated bucket seats, a cool box, dual-zone rear HVAC controls, a folding table, an ottoman, a shiatsu massager and, of course, DVD with wireless headphones.The list goes on.

The 2009 Lexus LS lineup is largely unchanged from the previous year.The LS 460 was launched for the 2007 model year and the LS 600h joined the line for 2008.

Lexus surpasses other luxury brands in terms of quality, durability, reliability, and desirability among American buyers, an astounding performance.The flagship sedan that started out as the LS 400 and then grew up as the LS 430 is now the Lexus LS 460.The Lexus LS challenges all comers as the best luxury sedan in the world.It competes with the Mercedes-Benz E-Class and S-Class, BMW 5 Series and 7 Series, and a few others.

The standard equipment list is long and the list of optional features is extensive.Options include Comfort Packages; the Navigation system packaged with the Advanced Parking Guidance Parking Package, or the Mark Levinson audio system, or with both the Parking Package and the Mark Levinson audio; a Pre-Collision System; One-Touch power operation of the trunk lid with power door closers; and numerous other conveniences.For the long-wheelbase versions there is an Executive Class Seating Package and a Rear-Seat Upgrade Package.

Safety equipment includes eight standard air bags to ABS (anti-lock brakes), electronic brake assist, ESP (electronic stability program), adaptive headlights, and tire-pressure monitoring.With the optional two-seat rear compartment, there is an additional air bag in the mix.Safety options include a pre-collision system that moves seats to a neutral position, closes the windows and sunroof, and tightens belts when the computers detect an impending collision.

As the flagship, the Lexus LS gets the most finesse of any of the Lexus L-finesse designs thus far.Its lines flow smoothly from its amazingly complex, crystal-like headlamp units, under the car, up over the roof and around the mirrors, with a short trip over the short rear deck to the integrated rear spoiler.After all that detail work on the exterior, they gave the car a drag coefficient of 0.26, tied with the best in the industry for a four-door sedan.Reducing aerodynamic drag not only helps fuel economy, it also contributes to reduced interior noise levels.

The headlights are automatic-leveling and also aim themselves to the left or right to better illuminate around corners, and the taillamps are LED units which deliver enhanced visibility to other drivers.

Optitron is the name used by Lexus to describe its electroluminescent gauges and displays, and they are lit by bright white LEDs for excellent readability, day or night.Almost all of the needles illuminate, dominated by the large tachometer and speedometer needles.Every single switch on the car is lighted for ultimate convenience.A new thin-film-transistor (TFT) multi-information color display delivers as many as 13 information and setting displays during driving.

New four-spoke tilt-and-telescope leather-and-wood steering wheels (heated on the uplevel versions) feature redundant controls for audio, information, cruise control, radar cruise control option, telephone, and a new brake-hold feature.To use the brake-hold feature, just come to a stop, push down the brake pedal, touch the button on the steering wheel, and the brakes stay on regardless of vehicle attitude until you touch the gas pedal.

The center stack of controls is beautifully integrated, as is every single piece of interior trim, and though there are lots of buttons, they are clearly marked in large type and lighted, so there will be little confusion after a couple of drives.The navigation display is large and bright, and the graphics are crisp and sharp.An auxiliary input is provided for MP3 players, such as the Apple iPod.The standard ten-speaker audio system sounds wonderful until you try the optional Mark Levinson Reference Surround Sound system, with 19 speakers and 450 watts, which we think might just be the single best automotive sound system on the market.

The LS is a big, roomy and comfortable luxury sedan, with generous interior dimensions and 18 cubic feet of trunk space, enough for four sets of golf clubs.

The long-wheelbase L versions offer more almost five inches more legroom, by virtue of their greater length, and the option of a luxurious rear-seat setup with two reclining heated bucket seats, a cool box, sunshades, additional climate ducting, and dual-zone rear HVAC control.Yet another configuration, the Executive-Class Seating Package, adds a folding table and a right rear seat with a built-in ottoman section, shiatsu massager, an extra air bag, and a rear roof-mounted 9-inch DVD screen and two sets of wireless headphones.No car manufacturer this side of a $350,000 Maybach offers this kind of rear-seat setup.

The LS 460 has a base curb weight of 4350 pounds, and its engine is smaller than those in some of the German competitors.Yet it can accelerate from 0-60 mph in a mere 5.4 seconds, and it's good for an EPA rating of 24 mpg Highway.But acceleration is only a tiny part of the story here, and the engine is only a part of that.

The LS 460 is the first car in the world with a computer-controlled eight-speed automatic transmission, a transmission that offers great acceleration with nearly imperceptible upshifts and downshifts, manual or automatic shift control, and that great highway mileage in eighth-gear overdrive.

Moving off from rest with authority and acceleration seems like child's play for the LS 460.The engine, transmission and driveline set the standard for quietness and smoothness.We found the LS 460 to be very, very quiet and nearly vibration-free.It seems much quieter than the competition, whether at 30 mph or 130 mph, its regulated top speed.

The electrically powered steering system is terrific.It doesn't feel any different than hydraulically powered steering, and it has progressive assist that decreases with speed.The steering, brakes and engine are linked together into electronic stability control, which Lexus calls Vehicle Dynamic Integrated Management (VDIM), and which includes all the functions of anti-lock brakes, traction control and stability control to help keep the vehicle going where the driver intends and thus to reduce the chance of a spin on a slippery surface.

All-wheel drive is available on all models.The operation and driving feel of the Lexus all-wheel drive system is about as transparent as it can be.There is no sense that it is searching between the front and rear wheels, and has none of the torque steer that accompanies just about all front-drive vehicles and many with all-wheel drive.

Parking and maneuvering are surprisingly easy given the size of the LS 460 L and LS 600h L.Thanks goes to a relatively short turning radius and electronic power steering.The Intuitive Park Assist feature can be used to allow the car to park itself.We tested the Intuitive Park Assist system, thinking anyone who knows how to parallel park will consider this an unnecessary, slightly insulting adornment.However, it really works.Actually, it works great.We found ourselves using it over and over.The trick is to scan in the exact size of the parking space, then keep a foot on the brake while the car automatically maneuvers itself into the spot.It takes about 10 seconds.

The LS 600h L, if anything, is even smoother.The hybrid system, in which the 5.0-liter V8 and the electric motor can work together, can provide performance equivalent to other V10 or V12 powerplants, and smoothness to match.The 389 horsepower of the engine, matched with the enormous torque of the electric motor, means that this car that weighs 5049 pounds can, according to Lexus, accelerate from 0-60 mph in just 5.5 seconds, and it is rated at 20 mpg City, which is more than what you might expect from a mid-size sedan with a V6.While hybrid powertrains deliver excellent fuel economy, their strongest forte lies in reduced emissions.According to Lexus engineers, the LS 600h L produces exhaust emissions nearly 70 percent cleaner than the cleanest competitors.

The hybrid drive system uses two powerful electric motors and a newly developed battery pack that is lighter and stores more electricity than previous systems.The system is capable of driving the car in electric only mode, or with a combination of gas engine and electric motor.The battery system consists of 288-volt DC Nickel Metal Hydride pack located behind the rear seat.In the trunk is a 12-volt auxiliary battery to power the audio system, navigation and lighting.The electric motors, MG1 and MG2, perform specific functions.Each can operate as both a motor and generator.MG2 is the drive motor.MG1 is used as a starter motor and acts as an engine-driven generator to charge the battery pack or provide additional power to the drive motor, MG2, as needed.

The LS 600h can operate in EV Mode, in which the vehicle will stay in electric-only mode at speeds below 25 mph for about a half mile.This feature might be useful to glide into the garage silently if you get home late, or get to a gas station if you ran out of fuel or maybe for use in stop-and-go commuter traffic.

Even though the hybrid is equipped with regenerative brakes, which recharge the battery as the brakes are applied, brake feel is typical of a standard car equipped with strong disc brakes, an impressive engineering achievement.

NewCarTestDrive.com correspondent Jim McCraw reported from Detroit, with John Stewart reporting from Southern California.