Lexus RX350 vs Lexus RX450H

What's the difference?

The RX is a big SUV that doesn't always look, or drive, like one, and – in 500h guise especially – can put a smile on a driver's face, too.

Gone are the cabin quirks and the polarising design elements (well, mostly...), and in their place you'll find a solid, premium-feeling family offering without much in the way of drawbacks.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

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 The media/sat nav system is hopelessly outdated and the drivetrain fails to deliver a significant performance or fuel benefit (although, given its 2.2 tonnes, perhaps it delivers a miracle).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.

Honestly, the Lexus RX looks far more powerful, and cohesive, in the metal than it does in some photos, and in the right colour (we're fond on the deep black or the copper-rose hues), it looks downright fetching.

That Predator-shaped front-end is massive, but the way the Spindle grille kind of bleeds in the body work at the nose of the vehicle is a neat trick, and the whole design ethos gives the RX a sportier, more modern, and more intimidating, energy from almost every angle.

Perhaps the most clever element though is the wave-like design piece that links the rear window with the boot, somehow managing to shrink almost-five-metre SUV (visually, at least), and leaving the RX looking more sporty than hulking.

The door handles are cool, too. They’re fixed, and you just touch them to open the door, with a similar system used once inside to get out again.

Inside, Lexus has gone for a clean, modern-feeling space, and, thankfully, there isn't a Remote Touch trackpad in sight. Instead, you can choose between two screen sizes – 9.8- or 14.0-inch – which kind of dominate the dash, while the air-con controls are digital and interactive, too.

It must be said, though, some interior treatments feel far more special than others, and while Lexus in Australia isn't spilling on specifics for our market just yet, the top-spec models will almost certainly feel more plush than the cheaper ones.

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.

The entire RX range now rides on Lexus' GA-K platform, which is lighter (-40kg), more rigid, and offers a lower centre of gravity (-15mm) than the model it replaces.

The RX is wider (+25mm to 1920mm), lower (-10mm to 1695mm), but no longer (still 4890mm) than the outgoing model. But Lexus has lengthened the wheelbase (+60mm to 2850mm) to earn some extra backseat space for rear riders.

And it must be said, there is lots of room for backseat riders. Sitting behind my own 175cm driving position I had more than enough knee room, and enough head room, and a general feeling of airy spaciousness.

Elsewhere you get the usual practicality perks, with two cupholders up front, two more in the pull-down seat divider that splits the rear seat, and there are two ISOFIX attachment points in the back seat, too.

Charging is handled by a four USB ports, and depending on the trim/spec balance Lexus in Australia shoots for, you should at least find vents with temp controls for backseat riders, too.

Lexus is yet to confirm the luggage space specs for the new RX, but given it’s only being offered with five seats, and that there’s been no change to the vehicle’s length, you can expect a fair bit of room for bags in its auto-opening boot.

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.

Let’s start with what we’re not getting at launch. Internationally, there's a new plug-in hybrid variant that pairs a 227kW hybrid system with a 18.1kWh lithium-ion battery for an EV driving range of more than 65kms, but fight though Lexus in Australia did, it couldn't secure the model for our market at launch. It wants it though, and badly. So watch this space. 

Instead we get three options, including the RX 350h, which pairs a 2.5-litre petrol engine with Lexus' existing hybrid system to produce a total 180kW and 316Nm. It's paired with a constantly variable transmission and will be offered in two- or all-wheel drive.

There’s also a turbocharged 2.4-litre petrol engine on offer in the RX 350, good for 205kW and 430Nm, and paired with an eight speed automatic and AWD.

But the powertrain I really, really like lives in the RX 500h F Performance, and pairs a 2.4-litre turbocharged petrol engine with an electric motor up front, and a second at the rear axle, for a total of 273kW and 551Nm.

The all-new hybrid system has been designed with turbocharged engines in mind, and features a single electric motor at the front, and a bigger rear motor, with the latter able to provide real driving power to the rear tyres - and contribute to a sprint to 100km/h of just 5.9secs.

Lexus calls it an 'eAxle' motor, and it can deliver some 76kW to the rear tyres. It pairs with a 'DIRECT4' all-wheel drive system which the brand says improves "handling, controllability, and feel."

Fitting, then, that it features on the RX 500h F Performance, which also introduces a new go-fast tier for the Lexus brand (though one you can expect to see more frequently in the near future), and which sits between the existing F Sport and the top-tier, full-fat F models.

The brand says things like bigger brakes, performance components and the highest power outputs will be reserved for the F Performance models. And so it is with the RX 500h F Performance, which welcomes six-piston front brakes, adaptive variable suspension, dynamic rear steering and 21-inch wheels.

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.

Let’s start with the pure-petrol RX 350, which will sip a claimed 8.8 litres per hundred kilometres on the combined cycle, and will demand premium petrol. The RX 350h is more fuel efficient, demanding 6.4 to 6.7 litres per hundred kilometres on the combined cycle.

But the most impressive is the RX 500h, which Lexus says will need 8.2 to 8.5 litres per hundred kilometres — making it more efficient than the petrol-powered RX 350, despite producing an extra 68 kilowatts of power and 121 newton metres of torque.

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).

Right, let’s cut to the chase here. I like the way the all-new RX family drives, pretty much across the board. If that’s all the information you want or need, feel free to check out here and move on to the next sub-heading.

Still here? Ok, then let’s go a little deeper.

None of the powertrains on offer feel under-powered in the RX range, which is a good start, but they all do their jobs a little differently. 

The RX 350 is probably the most familiar, with a traditional automatic and that well-known petrol-powered punch. It’s not the most powerful engine on offer here, but it’s more than enough to get the RX up and moving — but, for mine, it can feel a little thrashy (or like it’s straining a little too hard), when you really start to push it, but such is the price you pay for a four-cylinder engine pushing a large SUV.

Next up is the RX 350h, which Lexus reckons will be the best-selling model in Australia. Lexus and Toyota have been doing hybrid powertrains for some time now, and the system fitted to the new RX is predictably solid-feeling, though it too has its drawbacks – namely that the constantly variable transmission can drone on and on under constant acceleration, and even the commendably insulated cabin can’t block it out completely.

So if this is a Goldilocks’ scenario, then the just right has to be the RX 500h, which blends its powerful powertrain with a traditional-feeling automatic to deliver plenty of performance and a tight, engaging drive experience that makes it feel as though the big SUV is somehow shrinking around you from behind the wheel, courtesy of the best performance kit (brakes, adaptive suspension, etc).

But to be honest, no matter the RX, the thing that really stands out here is its on-road dynamics. The car doesn’t really wobble about, there’s not much in the way of body roll, and it feels tight and confidence inspiring, no matter the model - but especially the rear-wheel-steering equipped 500h.

The RX also does a commendable job of locking the outside world outside of the cabin. Where you want it to be a calm and sedate family hauler, it can be that. But it can also put a smile on your face on the right road, too.

And that, I think, is something to be celebrated. And also not something we’ve come to associate with Lexus over the years. But that’s now beginning to change. Long live F Sport Performance, then.

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.

The Lexus family is covered by a five-year, unlimited-kilometre warranty, which is about bang-on in the premium-vehicle space. 

While servicing details are yet to be confirmed, the previous RX required a trip to the service centre every 12 months or 15,000kms, and it will fall under the brand’s capped-price servicing program, and the Lexus Encore program, which offers all sorts of perks to owners.

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.