Review: Lexus LS600hL hybrid

With the LS600hL, Lexus has given the hybrid propulsion system popularized by the Toyota Prius some serious muscle and cloaked it in luxury robes. The "h" stands for the hybrid V8/electric motor powerplant that drives all four wheels and the "L" is for the long wheelbase, which describes the expansive but not quite Maybachian rear passenger area.

Perhaps unsure about whether to flaunt the power delivered to the wheels or the vehicle's claim to greenness, Lexus has chosen to affix "hybrid" badges so small and out of sight (on the bottom of the rear doors) that they border on invisible. The trunk deck spells out LS600hL, but its message is probably lost on most.

Speaking of messages, one has to wonder what this car's statement is. A luxury hybrid will strike some people as absurd, given the premise that a $120,000, 438-hp, 2.5-ton vehicle can't be seen to be treading lightly on the planet. Another perspective is to view this vehicle as providing the ride of a luxury guzzler on the energy budget and atmospheric footprint of a lowlier vehicle. Another verdict might be, "It's new, it's the top Lexus, it's clever as sin and I want one."

Compared with a similarly equipped LS460L that comes only with a gasoline-fueled V8, the LS600hL hybrid carries a premium of $32,660, so clearly this vehicle will not recoup its higher cost in gas savings. My local Lexus dealer told me his first LS600hL buyer wanted the car for three reasons: it is the most expensive Lexus; it has all-wheel drive; and his would be the first in the neighborhood. The dealer predicted that the thought process behind most LS600hL sales would be similar.

Over the course of three days in a prototype LS600hL that Lexus lent me in August, I searched for this undeniably ingenious car's message by driving it 900 miles. Since our household includes a 2007 Prius, a 2002 LS430, and a 1991 LS400, I was able to compare the LS600 hybrid with both its propulsive inspiration and its forebears in the luxury sedan lineage.

Much as I admire how the Prius fulfills its mission, it is of course a lumpy little wheezer beside the LS600, but after a slow start it has suddenly become mainstream because its unique body style needs no badges to proclaim its greenness. As of late summer, Toyota has sold more than 110,000 Priuses in 2007, and it was the best-selling car in the U.S. in July, with sales of 16,062, up 44 percent over the same month last year. How mainstream is the Prius? The other day, I saw a black one sporting skull-and-bones and flame decals. Behold, the eco-badass.

As a driving experience, the LS600 is a marked improvement over the already silky and adequately powerful (290-hp V8) LS430. The new car's electronic steering is more precise, and its three suspension modes offer taut ("sport"), the bland LS430 standard (a nameless intermediate switch setting), or "comfort" (which produces a more wallowing motion than the masterfully damped original LS400). As the driver, I preferred the LS600's sport mode; a dozen people who rode as passengers in the car unanimously preferred the intermediate mode over the comfort mode.

A BMW enthusiast hoping to convince me to buy his 530i recently dismissed the Lexus LS as being "designed by Japanese anesthesiologists." Granted, the BMW is more exhilarating to drive, but there should also be no disputing how difficult it is to engineer a car as smooth and silent as an LS and how well Lexus has succeeded in its mission.

The right rear seat in the LS600 is for the alpha passenger since its comforts (once the front passenger seat has been motored fully forward) include a retractable leg-rest, swiveling table, recline, and massage. The left rear seat offers recline, and either throne is comfortable for watching a DVD on the screen that swings out of the headliner. With the touch of a button, sunshades emerge from the door structure and parcel shelf to cover the glass to the sides and rear. The interior appointments in our test car-from the alabaster leather and ash woodwork to the buttons and chromed handles-were flawless, making this passenger compartment a fine place to cover the miles to and from a business jet's cabin.

Brilliant Systems

The driver has at his disposal the expected array of gadgetry, plus some peculiar to this hybrid. As well as such brilliant systems as distance-maintaining cruise control (alerted by a signal transmitted through the radar-transparent Lexus grille emblem) and self-parking, the LS hybrid presents the driver with pictograms and bar charts that show what is driving the wheels and how efficiently. In a nutshell, the "hybrid synergy drive" captures energy that would otherwise be lost overboard during coasting and braking and stores it in nickel metal hydride batteries behind the rear seats that not only drive the electric propulsion motor but also encroach significantly on trunk space.

Each 50 watt-hours of recaptured energy earns an E on the consumption bar graph, which is updated every minute (every five minutes in a Prius). Long stretches of powered cruising on the level earn no Es, but the coasting and braking of driving in traffic do create energy to be recaptured. In the absence of downhill coasting or braking, the gas engine will occasionally drive the motor as a generator to top up the NiMH batteries.

Even on the gas-powered LS, the engine is inaudible when idling, with only the tach to confirm that it is running. Pull up at a stoplight in the Prius, however, and the noticeable automatic shutting down of the gas engine screams "engine failure" to the pilot in you. Like the gas LS, the hybrid Lexus keeps its mechanical noises to itself, too.

Both the hybrids initially move from a standstill on electric propulsion, but the kicking in of the gas engine with sufficient demand from the right foot is prominent only in the Prius. In the LS, it is so subdued as to pass almost unnoticed were it not for the rev counter jumping off the pin and a stronger push in the back. The Prius has no tachometer, sending word of internal combustion to its occupants' ears instead.

The LS600hL is ingenious, spacious, and luxurious, but its "hybridness" somehow seems less relevant than the Prius'. On a quiet Sunday night, I was able to set the cruise control of the LS600hL to 60 mph in Syracuse, New York, and maintain that speed for almost the entire 287 miles to home in central New Jersey. The car returned 31.01 mpg, beating only narrowly the 30.5 mpg my LS430 achieved from its 4.3-liter, 290-hp V8 when left to saunter along the same trip undisturbed at the same speed. The difference is that the LS600hL is hauling more weight (5,049 pounds versus the LS430's 4,000) and has a lot more power to unleash if mpg is of secondary interest.

For the whole test, which included one 126-mile round-trip commute to work (some high-speed segments, some crawling in traffic) and local stuff running errands and scouting photography locations in upstate New York, the LS600hL returned an average of 24.52 mpg, again about the same as  my LS430 manages on similar runs.

One of the pleasures of driving a Prius is the feeling of being in a small sailboat rather than a powerboat and getting some free propulsive help (a debatable point given the mystery surrounding the price of replacement NiMH batteries). The reward for a light touch with your right foot is instantaneous, displayed on the energy consumption/ regeneration screen. While it was satisfying on the LS600 to see the mpg-per-minute bars peg out at 40 for eight or nine consecutive minutes, the hybridness was less apparent than the superb comfort of the ride.

The most direct comparison of all is with the LS460L, which is almost the same car with a 4.6-liter, 380-hp V8 solo under the hood, driving only the rear wheels through an eight-speed transmission. The hybrid weighs 717 pounds more, is 0.1 seconds quicker from zero to 60, gets 20/22 mpg EPA city/highway versus the non-hybrid's 16/24, and costs $32,660 more. According to the EPA's standard formula, the LS600hL hybrid and (in parentheses) LS460L compare thus: the cars will burn 16.3 (18.0) barrels of oil a year and emit 8.7 (9.6) tons of greenhouse gases. Perhaps this explains the tiny, obscurely positioned "hybrid" badges. The LS600hL is a fiendishly clever and comfortable car, but its hybridity makes it the greenest luxury car by only a surprisingly small margin.