The concept of frugality and an $115k luxury SUV would at first seem as far apart as Santa Claus and a suntan. But what may seem an oxymoron to most of us, Lexus sees as an opportunity for hybrid innovation. Back in 2005 Lexus released its first hybrid SUV offering the RX400h, its ‘have cake and eat it too’ appeal proved popular, especially in the North American market. For the 2010 model year Lexus has sparked up its second generation RX hybrid with the RX450h. The new model boasts increases to both power and economy but is it set to attract buyers to adopt hybrid technology? Or is it simply too big and expensive for the difficult kiwi market? Car and SUV spent a week with the hybrid Lexus to find out more.
Under the RX450h’s sheet metal lays a complex drive train system that makes use of a conventional petrol-powered V6 engine and also two electric motors. The 3.5-litre V6 engine produces 183kW of power and 317Nm of torque, and makes use of the Atkinson engine cycle to further improve fuel economy. The engine is matched to two electric motors, one in each axle, along with a power pack up front and Nickel Metal-Hydride (Ni-MH) batteries beneath the rear seats. With the three motors combined the RX450h has a total system power output of 220kW.
Further gains in efficiency have been made with improvements to the cooling and heat transfer of the engine and lightening the power pack and batteries. The Lexus Hybrid Drive system integrates with the petrol engine seamlessly and while the petrol motor takes care of open road/motorway driving the electric motors handle stop/start traffic duties. Gearshifts are worked by a CVT transmission that is aloof in its changes adding to the RX450h’s overall leisurely demeanor. So, what’s the result of all this modern technology?
In terms of performance the RX450h has seen a 10% increase over the outgoing model and will make the 0-100kmh sprint in 7.8 seconds, an impressive figure considering its burly 2,205 kg weight. However, there is a slow gain in momentum from standing till about 30km/h, dampening any plans of drag racing glory. After 30km/h acceleration is much brisker and the RX450h offers plenty of mid-range grunt for overtaking.
Fuel economy is quoted at a very frugal 6.4l/100km but we only managed an average of 8.9l/100km from a combination of motorway and round town driving. Our figure could probably be improved with more suburban driving that would make greater use of the electric motors.
Handling on the RX450h is impressive thanks largely to double wishbone independent rear suspension at the back and an active stabiliser bar system. An understandable level of body roll remains evident but the RX450h is dynamically competent on twisty roads. Unfortunately the electric steering is lacking in feel and feedback, this may suit some drivers but does little to encourage spirited driving.
Ride quality is a strong suit of the RX-series in general and the RX450h excels accordingly. Despite the low-profile rubber on the large wheels very little unsettles the cabins occupants even when driving on broken surfaces. A small amount of wind noise can be heard at higher speeds but when moving under electric power solely it’s completely silent.
Visually the RX450h defies the traditionally boxy stature associated with SUVs, instead maintaining a raked back profile and athletic stance. The overall aesthetic is a clear continuation from the outgoing model with the exception of a restyled nose with more dramatically angular headlamps and a larger, lower-set grille. A high chrome belt-line ascends the vehicle’s flanks tapering off when it reaches the thick rear pillars. At the back, mammoth jeweled tail lights and a sloping rear windscreen with a hidden wiper cap off the bulky muscular proportions. Chrome touches and 19-inch rims add class to what a distinctive and understated exterior aesthetic. Distinguishing the RX450h from its thirstier sibling are blue accents on the front badge and blue hybrid logos on the side skirts.
Step inside and the RX450h has lashings of luxury in a well-designed cabin that has a light and airy ambiance suitable for a top-end SUV. Splashes of woodgrain mix with black and silver high-grade plastics on the uncluttered and functional dashboard. A high-mounted eight-inch control screen sits in a recessed position at the top of the centre stack and displays audio and aircon settings, reversing camera, Sat Nav and a dynamic energy monitor display. It’s not a touch screen and is controlled via Lexus’ Remote Touch control system that could be likened to BMW’s iDrive but is easier to use. The control fits into the palm of your hand and is worked with fingertips and thumb, it navigating a cursor on the screen; it functions flawlessly and is an impressive piece of kit.
The perforated leather seats are soft and feel like they would remain comfortable on even the longest journeys. As you’d expect in a vehicle this size legroom and headroom is generous for all occupants. There are storage bins and cubbies all around and the rear seat can slide, recline and split 40/20/40 for versatility when loading large items. Cargo capacity is very good at 446-litres particularly considering the extra space taken up by the batteries. The RX450h also has a braked towing potential of 1,500kg. The lengthy standard equipment list includes all the usual suspects and a few extras like, IPod connectivity, Smart Entry, memory power front seats, electric tailgate, Bluetooth phone capability and a 9-speaker audio system.
Any safety questions are answered with 10 airbags in total including curtains and side airbags for rear passengers. Anti-lock brakes, stability and traction control plus a hill-hold feature are all standard as is a clever pre-collision radar system.
Overall, the RX450h is a practical and comfortable high-end SUV that handles well and can offer good pace once it’s off the mark. Will it attract buyers to adopt hybrid technology? Probably not, but it offers a green option in the SUV segment, albeit with a hefty price tag. Most RX-series buyers will still favour the petrol-only powered RX350 with its cheaper price tag and similar specification. There may however be some who desire a decreased carbon footprint while still benefitting from SUV safety and spaciousness. Those buyers will quickly move past the contradictory concept of a hybrid SUV and enjoy what is an impressively high-tech luxury vehicle.
Click through to the next page for a list of specifications
Price: from $114,990
What we like:
- Passenger comfort
- Equipment level
- Handling ability
What we don’t like:
- Initial take-off lag
- Price tag
- Slow evolution in exterior styling
Words and Photos: Adam Mamo
Lexus RX450h – Specifications
ENGINE – RX450h 5 Door SUV
Engine type Petrol
Engine capacity (cc) 3456
Engine description V6/DOHC/4v
Maximum Power 183kW @ 6000rpm
Maximum Torque 317Nm @ 4800rpm
Configuration V-formation Valvetrain DOHC – Variable valve timing STD
Fuel system EFI
Fuel type 95 RON ULP Recommended
Fuel economy ADR 81/01 Test standard – Combined (L/100km) 6.4
HYBRID SYSTEM – RX450h 5 Door SUV Hybrid Synergy Drive
Total System Output 220kW
Battery Nickel Metal-Hydride (Ni-MH) + 12 volt auxiliary battery
Motor Generator One (MG1) Generator/Engine starter, auxiliary power supply
Motor Generator Two (MG2) Generator/Drive power to front wheels
Maximum Power 123kW
Maximum Torque – MG2 (at motor) 335Nm
Motor Generator Rear (MGR) Generator/Driver power to rear wheels
Maximum Power — MGR 50kW
Maximum Torque — MGR 139Nm
4WD System Electronic All Wheel Drive
Driven Wheels 4WD
Transmission description E-CVT.
Steering type Rack and pinion
Steering operation Electronic Power assisted