Lexus RX 450h Continues Hybrid Firsts
The Lexus RX 450h hybrid will debut an all-new 3.5 litre Atkinson cycle V6
engine as part of the Lexus Hybrid Drive system
19th May, 2009
The debut of all-new Lexus RX 450h will herald another
hybrid world-first for Lexus, the introduction of the world's only Atkinson Cycle V6 engine in a
The Lexus RX 450h remains the only hybrid SUV available in Australia.
Since 2005, Lexus has been the only manufacturer to offer a range of luxury hybrid vehicles - and
its advances have led to the widespread adoption of hybrid technology worldwide.
The GS 450h luxury sedan was the first Lexus hybrid model in Australia.
Launched in May 2006, GS hybrid established a tradition of Lexus hybrid advances that has continued
with RX 400h and flagship LS 600hL.
The Lexus GS 450h set numerous world firsts - notably the first hybrid-powered rear-wheel-drive
vehicle and the first hybrid luxury sedan.
It featured a unique Electronic Continuously Variable Transmission (E-CVT), with two sets of
planetary gears and a two-stage planetary gear set to reduce the motor revolutions of the electric
drive motor at high road speeds.
The Lexus GS 450h also featured an all-new sequential shift function, to provide petrol engine
braking when required.
The Lexus RX 400h, launched in Australia in September 2006, was the world's first hybrid
petrol-electric luxury SUV.
It was designed to offer a major alternative to conventional petrol vehicles and the growing number
of diesels in the luxury SUV segment.
The Lexus RX 400h employed three electric motor/generators and a 3.3-litre VVT-i Quad Cam V6 to
develop 200 kW of power and return fuel economy of 8.1 litres per 100km*.
A compound planetary gear set in the Lexus RX 400h's hybrid transaxle acts both as a power-split
device and electronically controlled continuously variable transmission to drive the front wheels.
The rear wheels are electrically driven for vehicle take-off and acceleration to ensure optimum traction.
The flagship of the Lexus range - LS 600hL - employs a hybrid system layout similar to GS 450h, including the
two-stage gearing for the electric drive motor and sequential shift feature.
However, it provided more breakthroughs as it is the world's first all-wheel drive V8 hybrid. It has a gear
drive system to power the front axle permanent all-wheel drive.
The Lexus RX 450h has a 3.5-litre dual VVT-i V6 engine in lieu of RX 400h's 3.3-litre VVT-i V6 petrol
The new Lexus RX 450h's new 2GR-FXE petrol engine employs the Atkinson, or high-expansion, cycle for improved
It has a higher compression ratio than a conventional Otto Cycle engine.
The Atkinson cycle design makes full use of combustion energy, by keeping the exhaust valves closed until the
end of the expansion stroke.
The expansion stroke is extended, converting more of the combustion energy into torque on the crankshaft.
Lexus has combined the Atkinson Cycle with direct ignition, Quad-Cam Multi-valves and dual Variable Valve
Timing with intelligence (VVT-i) to optimise efficiency.
* Fuel consumption will vary depending on driving conditions/style, vehicle conditions and options/accessories.
Source of fuel consumption data: ADR81/02 combined cycle.