By Samuel Ee

IT has been called the most successful luxury SUV ever - and it's not difficult to see why.

The Lexus RX has all the qualities of an SUV - good visibility and spacious interior - plus the car-like handling and premium positioning that comes with the Lexus name plate. Perhaps because it is more crossover than SUV, in excess of one million RX units have been sold worldwide since the original RX300 was introduced in 1998.

The Japanese car maker says the RX is the most successful luxury product in Asia. It is also the company's biggest-selling model in the US. So it isn't a surprise that Lexus has placed a great deal of emphasis on the new RX350.

The 2010 Lexus RX350 is longer (by 35mm) and slightly taller than the car it replaces, with a longer wheelbase (plus 20mm). This third-generation RX also sports a new version of Lexus's L-finesse design. Otherwise, the exterior styling appears more evolutionary than revolutionary. But under the sheet metal of this pretty crossover, there has been a sea change.

The biggest transformation is the way the RX drives. The previous model was a competent performer but could hardly be called exciting. Like all Lexus vehicles, it was efficient, reliable and silent operation - and that was about it. The new RX350, however, will surprise you.

Basically, the front suspension has been optimised for the new platform and features new coil springs, while the rear struts from the previous car have been replaced by double wishbones.

The latter not only result in greater cargo space but much-improved handling. At a media launch in California's Napa Valley last month, the RX350 was so much fun to drive. It attacked the winding mountain roads enthusiastically, with the rear suspension keeping things tidy when going fast through the S-bends.

Even when you enter a curve too quickly you can reel in the RX350 safely just by easing off the gas pedal. But if you don't and you continue to gun the engine, the big crossover will yield in a very gentle, controllable drift. It helps that the new RX350's track is 70mm wider and there are bigger brakes. It is all very entertaining, though you will need some great roads like those in Napa County.

But more interesting is the fact that it can be accomplished in a relatively tall car. The RX350 is 1.725 metres high. Yet you don't get a sense of that because of the excellent driving position. Unlike with other Japanese makes, tall drivers should have no complaints about this particular Lexus. Besides the suspension, the all-new RX also boasts other enhanced features.

Power from the revised 3.5-litre V6 has risen five hp to 275 hp but the 346 Newton-metres of torque have been maximised, with 90 per cent available from 2,300 rpm. The engine is mated to a new six-speed multi-mode automatic transmission, which makes for quicker shifting and better fuel economy than the old five-speeder. The new gearbox, which has a manual shifting mode, is also six kg lighter.

Amid heightened consciousness over fuel economy, the RX350 has a new Eco Driving indicator light, along with an Eco zone to display a current fuel economy bar graph and to alert the driver when they are achieving low fuel efficiency.

Another new feature is the Head-Up Display. HUD projects the speed reading and navigation symbols on the windscreen, but sadly this slick gizmo will not be available in Singapore when the RX350 is launched here next month. Neither will the new Remote Touch console-mounted controller.

But other improvements we will enjoy are the standard 10 airbags and doors that extend over the side sills to keep legs and clothing clean when entering or exiting.

In addition, there is a new rear wiper that is neatly concealed in the roof spoiler and a new SmartAccess keyless entry system that replaces the usual rubber button on the door handle with an unobtrusive touch sensor.

All of this should mitigate the somewhat bland-looking cabin and thick A-pillars that can affect forward visibility in built-up areas, or an engine that may lose its usual Lexus hush under heavy acceleration. Ultimately, those who buy an RX350 are attracted by a premium product with a high level of comfort and useability. And now that it offers an entertaining drive, too, things are all the more interesting.

samuelee@sph.com.sg

» More shots of Lexus RX350