LEXUS has launched its third-generation medium luxury SUV, the RX350 – a bigger, more sophisticated model that is also more than 10 per cent dearer than its predecessor.

The RX350 is an important model for Lexus, as it accounts for more than a third of all Lexus Australia sales. The new model arrives just three months after its international debut at the Los Angeles show in November.

The fresh-bodied RX has a revised engine, new transmission, new suspension, new all-wheel-drive system and has new features such as active radar cruise control, proximity card locking and starting system and sophisticated central controller. It is marginally bigger and heavier than before, but slightly more fuel-efficient.

The new RX350 will arrive with three model grades – Prestige, Sports and Sports Luxury.

The new model costs around $10,000 more than its Sports and Sport Luxury predecessors, while even the new entry level Prestige model costs $4000 more than the previous entry-level Sports model.

The new Lexus central controller, Lexus Remote Touch, is similar to BMW’s iDrive.

The device features a mouse, menu and map buttons, along with a side-mounted display and dual enter switches to assist driver or passenger operations.

Lexus says the control screen is easier to see due to changes such as a higher-mounted screen resulting in a 30 per cent reduction in eye movement over the previous RX.

The system uses adjustable feedback to assist the driver in selecting the appropriate function.

The Sports Luxury has a Smart Entry and Card Key system, similar to those on various Renaults.

The Smart Entry design, replacing the previous black button on the doorhandle, uses a 3.35mm-thick Card Key slightly smaller in area than credit card. Like the Renault keycard system, a conventional key is included in the card to fit a conventional lock barrel on the car in case of system failure.

The Smart Entry system also employs a proximity set-up, which requires a touch on either the top, or bottom, of the door handles to unlock and lock the vehicle’s doors when the key card is between 0.7 and 1.0 metres from the locked door.

The RX350 also retains the power tailgate which has been redesigned to offer greater jam protection, and now features separate lock and unlock switches, replacing the previous model’s single button.

Improvements to safety include a two-stage driver’s SRS airbag, a newly adopted twin-chamber front passenger SRS airbag and full-length side curtain-shield airbags and rear-seat side SRS airbags.

The RX350 also has new active front-seat head restraints and rear-outboard seat pre-tensioning seatbelts with force limiters.

Sports and Sports Luxury models feature the Pre-Collision System, which relies on millimetre-wave radar technology to recognise a possible frontal collision and prime the brake assist, retract the driver's and front passenger's seat-belt in anticipation of the crash.

The improved petrol 2GR-FE 3.5-litre dual VVT-i V6 engine now delivers 90 per cent of its peak torque from 2300rpm to 6100rpm and is linked to a six-speed sequential-shift automatic (in place of the previous model’s five-speed unit), and a new active all-wheel-drive system.

There are myriad minor changes to the engine, such as a re-designed induction system, a re-designed exhaust system, new valves and new camshaft profiles and the new engine has 204kW of power at 6200rpm and 346Nm of torque at 4700rpm

There are minimal peak output gains: maximum torque has been increased by just 4Nm, and maximum power by 1kW.

The engine revisions and other improvements allow a 3.5 per cent increase in fuel efficiency, according to Lexus.

The RX350, like its predecessor and most of its competitors requires a minimum of 95RON premium unleaded fuel to run most efficiently.

Fuel consumption is 10.8L/00km, compared with 11.2 litres per 100km for the previous model. The new model emits 254g/km of C02.

The new six-speed Lexus U660F automatic features improved technology for the torque converter, planetary gear set, solenoid, bearing and clutch piston and is 6kg lighter and 19mm shorter than the five-speed transmission.

Key aspects of the auto’s improvements include electronic control software that has increased the range of low-speed torque-converter lock-up control to save fuel.

Greater use of aluminium for more bulky components and a new asymmetrical differential case are key contributors to the weight reduction.

Other changes include a new transmission casing that lowers the engine output shaft by 16mm, aiding to lower the centre of gravity.

The RX350’s new Lexus Active Torque Control all-wheel-drive system controls torque distribution between the front and rear axles by using an electromagnetic coupling in the rear differential housing. The system only drives the front wheels when the vehicle is cruising, and shuttles torque to the rear axle on demand to a maximum ratio of 50:50 front/rear.

The all-wheel-drive system also can be locked 50:50 manually by the driver up to speeds of 40km/h.

The new Lexus has electric power steering for the first time. The steering ratio has been lowered from 16.3 to 14.8:1, while turning circle remains identical to the previous model at 11.8m.

The new RX350 body is longer, wider and lower than before and wheelbase has been increased by 25mm, front track by 55mm and the rear track by 65mm. Ground clearance is down 10mm to 180mm.

Kerb weight of the new model is up 120kg, from 1855kg in the previous model to a minimum of 1975kg.

The RX350’s suspension and brakes have been improved. The new four-link rear suspension allows the coil springs and dampers to be positioned under the floor for increased luggage room, the net result being a 30mm lower luggage floor and 150mm more usable luggage width.

Ventilated front brake disc diameter has increased from 319mm to 328mm and twin-piston front callipers have replaced single-piston calipers.

At the rear, 309mm diameter solid discs have replaced 288mm solid discs and the braking system also has a new, lighter, more compact brake actuator.

Wheels are 18x7.5 alloy (Prestige) 19x7.5 (Sports and Sports Luxury) and tyres are 235/60R18 (Prestige) and 235/55R19 (Sports and Sports Luxury).

The RX350 continues with a 1500kg braked (750kg unbraked) towing capacity.

The Prestige has as standard equipment a Head-Up Display (HUD), Remote Touch navigation system, Bluetooth and iPod connectivity, satellite navigation, HID headlights, Lexus Rear Guide assist with camera, 10 SRS airbags and Lexus Vehicle Dynamic Integrated Management (VDIM) traction control.

The VDIM package combines vehicle stability control with co-operative steering function (VSC+), Traction Control (TRC), ABS, Electronic Brake-force Distribution (EBD) and Lexus Brake Assist.

The Sports model has the additional features of sunroof, shadow chrome 19-inch alloy wheels (instead of 18-inch), Pre-Collision System (PCS) and radar Adaptive Cruise Control (ACC).

The top-of-the-range Sports Luxury also gets bright chrome 19-inch alloy wheels, intelligent adaptive headlamps (i-AFS), heated electro-chromatic exterior mirrors with memory, side-view camera, and clearance/reversing sonar, leather and wood-rim steering wheel with controls for voice recognition, side-view camera and ACC, power driver and passenger front seats (with lumbar adjustment and memory), heated and air-cooled driver and passenger front seats and Mark Levinson sound system. The Mark Levinson 15-speaker sound system is a delete option for Sport Luxury, which takes $3000 off the $97,900 price.

All Lexus RX350 models have a temporary spare wheel as standard equipment, although customers can request that a full-size spare be fitted instead.

New RX350 will be available in a choice of nine exterior colours, including four new colours: Blue Pearl, White Pearl, Sapphire and Metallic Silver. Other colours include Graphite, Onyx (black) and Metallic Beige, Vermillion (red).