Lexus NX300H vs Lexus RX450H

What's the difference?

The all-new NX is a massive step forward over its popular predecessor.

In every way, it is an improvement, with better refinement, comfort, performance, efficiency, safety and choice.

Indeed, look out, Audi, BMW, Mercedes and Volvo: the NX has finally come of age. If we were in the market for a luxury medium-sized SUV, we'd definitely have the Lexus on our shortlist, especially the incredibly efficient hybrids.

Europe, you've been warned.

The RX is a little frustrating - it's going after Mercedes and BMW and Audi in a hotly-contested space and falls over in a couple of key areas. The media/sat nav system is hopelessly outdated and the drivetrain fails to deliver a significant performance or fuel benefit (although, given its 2.2 tonnes, perhaps it delivers a miracle).

It does come with a rock-solid, scandal-free reputation, a reputation for spectacular customer service, it has a lovely cabin and it's certainly an individual looker. For plenty of people, that's quite enough.

UX, NX, RX, LX, RZ... Lexus' nonsensical naming strategy can be quite flummoxing.

Just remember that the NX sits above the smaller UX but below the larger RX in the brand's burgeoning SUV stable. It's also closely related to the wildly-popular Toyota RAV4 – though you'd never know by looking at them side-by-side.

At first it may look much like the old model, but the new NX has switched to the latest RAV4's advanced Toyota New Global Architecture, known as GA-K in Lexus' lexicon.

Basically, it allows for a vehicle that's between 20 and 30 mm larger than before, to help improve overall proportions. And with this considerably bigger canvas to work on, it also means that Lexus's stylists have had more freedom to evolve the brand's design language. Albeit at a glacial pace from an exterior point of view.

Starting from the front, the controversial 'spindle' grille has been toned down a bit and the headlights have a neat Lexus 'lightning rod' tick motif, while – looking at the side profile – a startlingly cab-backward shape gives it a surprisingly sleek silhouette.

The extra length and stretched wheelbase let the design to breathe more than before, bringing with it a more graceful and elegant aesthetic.

Finally – and this is a brand first – the new NX's rather nondescript rear has 'LEXUS' spelled out in letters, with no sign of the company logo.

There's a lot of RX and there's a lot going on in that creased, folded and teased sheetmetal. It's a unique design, with a huge 'spindle grille', big lights and the fast glass both front and rear.

It positively screeches Lexus DNA and was a polarising force on our driveway for the week. Most weren't sure, but knew for certain it was a Lexus.

Aggressively flared wheelarches like this aren't common on SUVs (although the squared-off ones are). It's right up on stilts, but the 20s you find it rolling on help to reduce its visual bulk.

That wacky rear quarter glass reminds me of the BMW i3's but it's a Lexus SUV signature. It's quite striking. Do I like it? Not really, but that's completely subjective. You can tell, though, it's built tight as a drum.

Inside is a bit calmer, beautifully laid-out and built to last. The materials are almost all top notch, with lovely switchgear and the real leather is really nice.

There is absolutely nothing avant-garde in there (apart from maybe the pinstripe effect on the centre console), it's all terribly comfortable and easy on the eye. But not exciting, though not all Lexuses are.

This particular car is very US-centric and, if I may, a particularly sunny and humid part, so it can't be too wacky.

For the really big design step-change, you'll need to step inside...

Hallelujah! Lexus has finally forsaken its weird, futuristic dash design elements for a simpler and far-more intuitive look that finally banishes unnecessary complication while still appearing progressive.

Somehow, there are now 33 fewer switches than before, aided by permanent virtual short-cut buttons on both of the touchscreens on offer.

Lexus has clearly been listening!

So, now, what we have here is an attractive, functional and superbly built interior (save for a couple of very-atypical Lexus rattles in these early production cars we drove), boasting quality materials that rate highly on all the important sensory metrics: lush to the touch, easy on the eyes and lovely to breathe in... and breathe out again!

Other plus points include a gorgeous steering wheel, attractive instrument dials, endless storage and climate control that's so effective it pretty much creates a microclimate within your personal space.

Brilliant seats, with ample adjustability, provide comfort and support even after hours ensconced within them, while the driving position is enhanced by thoughtful placement of most major controls - including the natty little gear lever and big old paddle shifters.

It's also worth pointing out a couple of surprise-and-delight features – starting with the 'e-latch' electric door handles, with sensors that delay opening if there are cyclists or pedestrians on approach to prevent striking them, as well as a manual override should the battery go flat.

There's more, like the wireless phone charger tray that also slides to reveal a hidden cubby area; centre-console lid that opens sideways FROM BOTH DIRECTIONS – what sort of sorcery is this?? – and optional digital rear-view mirror that works like X-ray vision in seeing through obstructions... handy for when back-seat passengers' beehives block the back view out.

However, after lavishing such intricate attention to detail, why does the instrument cluster's digital trip computer use the same cheap style and font as found in a lowly Yaris? It takes you completely out of the Lexus state-of-mind.

And, like me, you might lose your mind with the infuriatingly fiddly capacitive touch controls on models with the HUD. While it does provide a broad range of functionality that's displayed on the windscreen view, it's difficult to modulate accurately, and doesn't operate intuitively. Remnants of the fiddly old touchpad from the previous NX. Why can't Lexus just abandon such needless complexity? After a while I worked it out – but it's deeply distracting to use.

Oh well. At least the rear seat area is an improvement over the old NX, with more space, comfort and convenience features. Entry/egress is easy, with wide apertures that ought to make fitting in child seats less of a chore than before.

Most adults should find sufficient leg, knee, shoulder and head room back there, though a trio of adults might result in a very tight fit.

Rear facing air vents (with climate control functionality on higher grades), 12V power outlets, twin USB ports and a wide centre armrest with cupholders are included.

Further back, there's a handy (though not class-leading) 520 litres of luggage space regardless of powertrain, expanding to 1411L when the rear backrests are folded. Access is easy thanks to the wide door and flat floor, where a bit of extra storage and even space for the cargo blind are provided. Thanks, Lexus.

Note, though, that runflat tyres take the place of any spare wheel – a bummer if you're out on deserted country road late at night with no help in sight.

There is plenty of room inside this big unit, which is very welcome. Front seat passengers have lots of storage, such as a deep central bin under the armrest, dual cupholders and big door pockets with bottle holders.

Step into the rear and there is a ton of leg and headroom although the transmission tunnel intrudes slightly for the middle passenger. Chuck them out, drop the armrest and you have two more cupholders and each door has pockets and bottle holders.

The boot is pretty big considering the angle of the rear glass. You start with 453 litres (but an expanse of flat floor), which rises to 924 litres with the split-fold seats down. That seems conservative given just how much space you appear to have.

The RX450h F Sport lightens your bank account of $102,460 before on-road costs, the only hybrid SUV within cooee of this price.

That nets you 20-inch alloys, a 15-speaker stereo, dual-zone climate control, heated and cooled electric front seats, reversing camera, that ever rare CD player, keyless entry and start, a solid safety package, reversing sensors, active cruise control, sat nav, a massive sunroof, auto LED headlights, head-up display, partial leather interior, power tailgate, auto wipers and a space-saver spare.

The Lexus media system is run from the gigantic dash-mounted screen that is shamed only by those massive Tesla units.

Sadly, the joystick-style control remains as does the very confusing software system that is less than delightful to use. It's such a shame that a tech-laden machine is let down by the world's most baffling entertainment system.

Once you get it working and understand it, it's okay, I guess, but several years into this job I still can't easily fathom how it works. And that naff analogue clock...

F Sport cars also pick up adaptive suspension and a several driving modes to liven things up.

Here is where the NX shines, with clear options that provide very obvious benefits according to wants, needs and budgets. And there are even fundamental differences compared to the RAV4 powertrain, further justifying that premium 'L' badge experience.

Let's divide these into petrol and petrol-electric hybrid models, with petrols first.

The NX 250 is powered by a 2487cc 2.5-litre naturally aspirated direct-injection twin-cam four-cylinder engine, producing a healthy 152kW of power at a heady 6600rpm, and 243Nm of torque from 4000rpm to 5000rpm.

Drive is sent to the front wheels only, via an eight-speed torque-converter automatic. Tipping the scales at 1705kg, it's the lightest NX on offer, and thus delivers 89.1kW per tonne.

The NX 350 turbo version, meanwhile, uses a somewhat different four-cylinder engine as well as a variation of the eight-speed auto. A 2393cc 2.4-litre turbo unit, it pumps out 205kW at 6000rpm and 430Nm from a low 1700-3600rpm. It's also AWD only, which adds kilos. That said, coming in at 1860kg, its power-to-weight ratio is a stirring 110.2kW/tonne.

Moving to the series/parallel hybrids, both the expected-bestselling NX 350h and the intriguing new NX 450h+ PHEV are based on that 2487cc 2.5-litre four-cylinder atmo unit, tuned this time to offer 140kW and 136kW (at 6000rpm) and 239Nm/227Nm (from 4300-4500rpm and 3200-3700rpm) in the NX 350h and NX 450h+ respectively.

The NX 350h uses either a single synchronous permanent magnet 134kW/270Nm electric motor in the front-drive version, or two electric motors (adding a 40kW/121Nm generator on the rear, double wishbone axle) to create the AWD alternative. Their combined total power rating is 179kW. The NX 450h+ ups that to 227kW.

None are light, however. While the NX 350h 2WD weighs a reasonable 1810kg, the twin-motor AWD system bumps that up to 1870kg, while the NX 450h+ is a portly 2050kg. Result? The power-to-weight ratio for all three are 98.9kW/tonne, 95.7kW/tonne and 110.7kW/tonne – almost identical to that of the NX 350 turbo.

The hybrids' gearbox in question is an 'e-CVT' electronic continuously variable transmission, working with a lithium-ion high-voltage battery, while the NX 450h+'s EV drive's battery is an 18.1kWh unit.

So, no prizes for guessing which one is the most frugal...

You can choose three different powertrains in the RX - a 3.5-litre V6, a 2.0-litre turbo four-cylinder, or this one, the 3.5-litre V6 with hybrid.

As a series hybrid it can run for short distances on electric only before firing up the V6 to supply charging and motivation.

The 3.5 produces 193kW/335Nm along with the electric motor. That torque figure seems low and it probably is, but that's a function of the weird way of measuring torque from a hybrid unit. The combined power figure, however, is 230kW.

The hybrid system is hooked up to Lexus' CVT auto and sends power to all four wheels. Lexus says the 450h will complete the sprint from 0-100km/h in 7.7 seconds, which isn't bad for a 2210kg SUV.

All NXs require 95 RON premium unleaded petrol, and are emissions rated at Euro6b.

Not surprisingly, on the official combined run, thirstiest of the lot is the NX 350 turbo at 8.1L/100km (for a carbon dioxide emissions rating of 185 grams per kilometre), followed by the NX 250 at 6.9L/100km (158g/km).

The NX 350h cut that down to 5.0L/100km (113g/km for the FWD and 114g/km for AWD), while the NX 450h+, naturally, is the most economical by far, slashing that down to just 1.3L/100km, or 29g/km.

While we can't tell you what the NX 450h+ managed on test, the others didn't quite match their official numbers. Over several hundred kilometres, the NX 350 ranged from 9.3-11.3L/100km, the NX 250 7.5-9.3L/100km and the NX 350h from 5.7-6.8L/100km.

Note that the NX 450h+'s 18.1kW battery can only be charged using an AC outlet, meaning it'll need about 2.5hr to get the job done. Its EV-only range is about 70km on the WLTP score, or 87km using the less-realistic NEDC method.

At 55 litres, the fuel tank will allow the following combined average range between refills: 679km (NX 350 turbo), 797km (NX 250), 1100km (NX 350h) and a barely believable 4231km (NX 450h+, naturally).

The official combined cycle figure is listed as 5.7L/100km. And, uh, yeah, we didn't get that. I did manage 8.9L/100km over the week, which included a long motorway run from Sydney up to the Blue Mountains (a roughly 160km round trip).

The previous NX looked better than it drove.

Based on the previous-gen RAV4, it failed to rise above such humble underpinnings, despite all the extra design, comfort and equipment features Lexus created to help it do just that.

Sure, there were some very appealing things going on, including attractive styling, an intriguing interior, sumptuous seats and lots of kit to play with, but the Toyota's noisy, fidgety and tiring DNA soon became apparent, especially compared to rival luxury midsizers. And some of the dashboard multimedia controls were just down-right madness.

Building on the latest RAV4's set of modern, competent components, however, has fundamentally changed the NX.

For starters, it's much quieter inside. Whether at idle, travelling at speed, or traversing some pretty rough patches of road, the NX at last rides like something you'd expect a Lexus should. And given how noisy and droney most of its European rivals also are on Aussie bitumen, it gives the Japanese contender a handy head-start.

The same applies to how enveloping the soft yet supportive seats are, how settled the suspension feels and how calm the experience is. No previous Lexus SUV has seemed so... refined. Even the really big, expensive ones.

From the driver's point of view, the steering is beautifully balanced, for precise yet reassuring control at speed. This varies according to which grade you're driving, but as a whole, while not sporty like a BMW's nor as fluid as, say, a Mazda CX-5's helm, the Lexus walks that line between easy and involving quite well.

Ditto the handling and roadholding. The lightest of the bunch – the petrol-powered NX 250 and NX 350 turbo – feel ripe and ready for a hustle along a curvy ribbon of road, coming across as taut enough for tight turns yet supple enough to soak up the many bumps and thumps thrown up at them.

Switching to the NX 350h hybrid, there's a greater sense of mass, whether driving the front-drive 2WD or even heavier AWD version. As such, it's still quite dynamic, but not as athletic as the petrol-only models.

In terms of performance, there are no duds – and that's no surprise, as the previous NX's powertrains were pretty sound as well.

Though simply a front-drive version of the RAV4 Edge's 2.5-litre unit, the NX 250 seems more muted than the Toyota's application, and yet is willing to rev hard to hit the power band necessary for it to feel alive. At higher speeds, sometimes the raspy engine can sound a tad noisy when extended, but it's never harsh or rough.

Moving on to the NX 350h, it feels like, well, a heavier and quieter RAV4, not unexpectedly. Silent at take-off speeds, the engine chimes in fairly unobtrusively, providing plenty of oomph along the way, while the CVT seamlessly slices through each (artificial) ratios. After the petrol versions, the steering does seem a little more remote, and you can feel the extra heft through turns, but – again – the basics underneath seem right.

Accelerating hard on the open road does reveal that typical Toyota hybrid engine roar and CVT flair, but only when the throttle is prodded hard. Driven normally, the NX 350h is as smooth, swift and sweet as you'd expect. And definitely in keeping with brand performance expectations.

Finally, there's the NX 450h+ F Sport. At over two tonnes, Toyota and Lexus' plug-in hybrid debutante is not a flyweight by any means, yet having all that extra low-down mass does result in a slightly different driving experience.

Take acceleration: having access to 227kW of power and torque together at very low revs equals lots of thrust right from the get-go. And while it's not sports-SUV rapid, there's certainly enough punch to justify the F Sport badge. Similarly, the low centre of gravity that the 18.1kWh battery pack provides seems to promote hunkered-down road-holding attitude through tight turns, with minimal body roll.

Regardless of which NX you're looking at, quibbles are few. Occasional road and tyre roar are still a little evident over some surfaces; the adaptive cruise control and lane-keep technologies could benefit from some local fine-tuning so they behave a little more nuanced in Australian conditions (and that applies to most luxury SUVs nowadays); and the optional head-up display's capacitive controls located on the steering wheel spokes are distracting, difficult to modulate and needlessly complicated. They're so annoying we'd even untick the Sport Luxury option box to avoid it.

If we had to choose a favourite among the new NXs, it would probably be the NX 350h F Sport, since its adaptive sports chassis provides the best compromise between agility and suppleness; the NX 350 turbo is probably the most fun to drive hard and fast, while the base NX 250 is thoroughly competent and sufficiently luxurious to scare most rivals.

Could this really be a medium-sized Lexus SUV we're talking about?

We're not saying that the latest NX is perfect, but it now provides a very compelling argument not to buy European.

Right. So this is a salutary lesson about tyre pressures. The first few days the tyres were only pumped up to 200kpa (29psi). That's an easy 100kpa (14psi) short of the required 300 (43psi).

Every time I, or my wife, went around a corner, the big Dunlop Sport Maxx SPs would squeal and squirm and it was most unsatisfactory.

So check your tyres, because the extra 100kpa makes all the difference. Also, the number of service stations it took to find a working pump was unacceptable. Pull your socks up, Sydney.

Anyway.

Correct tyre pressures enacted, the big Lexus turned into a comfortable, competent cruiser. Its motorway performance is super-impressive, purring along the M4 and it's ridiculously poor surface like it was born to it. Which it sort of was.

The hybrid drivetrain allied to the CVT is mostly whisper quiet. It's not the most responsive combination, the initial step-off of the electric motor's torque soon giving way to the rubber band effect of the transmission.

It doesn't feel as swift as the claimed 7.7 seconds and it would be nice if the drive select dial made a genuine difference to the throttle and transmission's response.

In the city, it's a proper wafter, moving about the broken down city streets of Sydney without fuss and a plush ride that's a bit of a surprise given the huge wheels and substantial weight of RX.

It's all very easy and pleasant but the wild looks do not match the experience. Which is not a criticism, just an observation.

The RX ships with eight airbags (including knee airbags for both front seats), ABS, stability and traction controls, blind spot sensor, reversing camera, forward collision warning, forward AEB and reverse cross traffic alert.

There are three top tether restraints and two ISOFIX points. 

The RX scored a maximum five ANCAP stars in January 2016.

Lexus now offers a five-year, unlimited kilometre warranty with roadside assistance.

Furthermore, NX 350h hybrid and NX 450h+ plug-in hybrid models also feature a 10-year, unlimited kilometre battery warranty.

Service intervals are at 12 months or 15,000km, whichever comes first.

The NX also includes three years and 45,000km of capped-price servicing, with each one costing owners just $495 – and that's highly competitive pricing for a luxury brand.

Plus, there's also Lexus' 'Encore' aftersales subscription program offering myriad offers and services.

Lexus offers a fence-sitting four year/100,000km warranty with roadside assist thrown into the bargain for the same period. 

Service intervals arrive at 12 month/15,000km and there is, sadly, no capped-price servicing.

Lexus will, however, promise you a car for the day or come and get your car from you and drop it back when the service is done. And it will be washed and vacuumed. The website makes a big deal about that.