Lexus will soon enter the mid-size SUV
segment – and it’s leading owith a full hybrid powertrain
Lexus started developing a compact SUV in
2009. The NX 300h will hit the market later this year with a hybrid powertrain
that will help keep emissions to around 120g/km of CO2.
The
all-new Lexus NX SUV has been given an early unveiling this week, courtesy of
new leaked images appearing on an enthusiast forum overnight.
As part of an ongoing huge expansion of its
product portfolio, Lexus will later this year launch its first compact SUV to
rival the likes of the BMW X3 and Audi Q5. But while drivers will have to wait
until February 2015 to get their hands on the NX 200t – the derivative that
will sport the Japanese manufacturer’s brand-new 2-liter twin scroll
turbocharged petrol engine – the NX will launch with the 300h, a full hybrid
model capable of churning out 197ps/145kW, while targeting emissions of less
than 120g/km of CO2and offering fuel efficiency of 5.2 l/100km (54.3mpg).
Power for the NX 300h comes from Lexus’s
2.5-liter Atkinson cycle IC motor, generator, electric motor and battery. A
front-wheel-drive version will include one electric motor, while the
all-wheel-drive option will add a second e-motor.
The architecture, developed in Japan, is
largely tried-and-tested, according to the NX’s chief engineer, Takeaki Kato.
“The front-wheel drive system is basically carried over from the IS 300h,”
confirms Kato, whose previous credits include the IS and RX. “But the all-wheel-drive
hybrid system is developed for this vehicle, especially for this Lexus.
Development of that system started at the same time as development of the
vehicle itself, back in 2009.”
Kato says that the blend of low emissions
and impressive power output will ensure that the NX 300h surpasses its segment
competitors, which, in addition to Q5 and X3 includes the Volvo XC60 and
Mercedes GLK. The company is expecting strong sales from the new SUV – internal
predictions are that the NX will make up one-third of Lexus’s European sales in
2015 – and with the hybrid taking the place of a diesel option, the OEM is
expecting a strong uptake for this particular model.
The
2015 NX comes with a second powertrain, though: the predictable hybrid, which
puts out a total of 194 horsepower (against the 235 hp from the standard
2.0-liter turbo engine).
Although much of the hybrid technology is
familiar, there have been some interesting developments made for the NX. In the
all-wheel-drive offering, the two-motor system will be capable of optimizing
torque delivery. “According to your driving situation, if the engine decides
that sending torque to the rear would be the optimum driving situation, then it
would do that,” Kato adds. “But what’s different from the RX is that, with this
car, we tried to change the control so that it uses the rear motor more than
you would have done in the RX.”
Battery Integration
The situation of the battery for the NX
300h was also considered in the design of the vehicle’s silhouette. “We put the
hybrid battery under the rear seats,” Kato explains. “If we keep the same head
clearance, you end up increasing the vehicle height. Usually the highest point
is the front passenger’s head, but this particular design means that the rear
passenger’s head point is the highest. It’s a very unique roofline silhouette.”
According to the chief engineer, the vehicle’s appearance and powertrain
structure had to be considered in tandem. “We started off by saying that we’re
going to have the battery underneath the rear seats,” he adds, “So what’s the
roofline that will give us the design that we want? It was a trial and error
process.” The 230.4V, 192-cell battery comes from Primearth EV Energy while the
NX’s e-motors were developed in-house.
The
NX 300h uses the latest version of the company’s venerable hybrid drive system
consisting of a 2.5-liter Atkinson-cycle engine, generator, motor and battery.
Total system horsepower is 194.
The NX 300h includes sprung-weight damping
control to reduce pitching on uneven surfaces, as well as during heavy braking
and accelerating. The compact SUV’s all-electric range is limited to 2.4km (1.5
miles) at speeds up to 48km/h, although Lexus insists that the exact distance
will depend on terrain and state of charge.
