A BOOST gauge displayed proudly in the centre of its instrument panel signals the turbo-engine tech that headlines Lexus’s conventionally powered compact SUV.
The NX200t – sibling to the hybrid NX300h and $2500 cheaper, with the same features and equipment – ushers in the brand’s first turbocharged engine and, refreshingly, the technically interesting unit takes precedence over the brand’s more usual ‘premium this’ or ‘sports-luxury that’ message.
Lexus is late to the turbo party. Up until now, hybrids have hogged all its engineering efforts, though it spent nine years developing the 2.0-litre fourcylinder 8AR-FTS engine. And there’s cleverness to show for it.
The turbo four, already the subject of a Japanese SAE paper, brings a newly developed VVT-iW system. The ‘W’ appended to the faithful variable valve timing acronym stands for ‘wide’ – an inlet-valve-timing operating range wide enough that the mill can operate on both the conventional Otto and more efficient Atkinson combustion cycles.
No off-the-shelf unit, the turbo’s exhaust turbine housing is part of a single cylinder head/exhaust manifold casting. The twin-scroll snail – each scroll is fed exhaust gas by its own pair of cylinders – boasts a variable wastegate that’s opened not just to control boost pressure, but to minimise engine pumping losses. The turbo pumps boosted air to the engine via a liquid-to-air intercooler, sited close to the engine for throttle responsiveness.
The idle-stop system cranks the engine on throttle application.
The engine delivers its first power stroke in less than 180 degrees of crankshaft rotation and that can be felt in its immediacy.
Not a brand to leave room when it comes to refinement and reliability, Lexus gave the 175kW/350Nm engine balance shafts for smoothness and piston oil jets for cooling. The Euro-6 donk would be brilliant in something sporty, but this RAV4- derived luxo-SUV isn’t that car.
While the NX200t is smooth and brisk, with a hint of rortiness, the engine is largely over-refined into the background. And the six-speed auto refuses to let the driver tap into the bottom end of the engine’s repertoire (torque kicks off at 1650rpm, while power peaks at 5600rpm), preferring to drop a couple of ratios and use the revs, even in manual mode.
Despite a different suspension calibration to the hybrid, you will be disappointed if you’re hoping for profound dynamic improvements to go with the turbo-petrol’s extra performance.
Lexus might be blazing a snail trail, but more time is needed to sort the NX’s one-dimensional chassis, over-cautious ESC and numb electro-steering.
Model Engine Max power Max torque Transmission Kerb weight 0-100km/h Economy Price On sale Lexus NX200t Luxury AWD 1998cc 4cyl, dohc, 16v, turbo 175kW @ 4800-5600rpm 350Nm @ 1650-4000rpm 6-speed automatic 1755kg 7.1sec (claimed) 7.9L/100km $57,000 Now
Dynamics; polarising styling; auto is belligerent in manual mode Engine is a cracker; quicker and cheaper than hybrid NX; interior
THE NX200t’s official economy figure of 7.7L/100km for the front-drive model is decent for the class, but can’t match turbo-diesel rivals, and is about 2L/100km more than the hybrid. At 7.3sec for 0-100km/h, it’s a worthwhile two seconds quicker than the 300h. If you’re wondering how the new engine would go in something lighter, there’s a good chance we’ll find out because it’s being considered for other models, including the IS sedan.