Mercedes-Benz E400 vs Lexus RX

What's the difference?

A convertible that doesn't feel like one when the roof is in place is no easy task to build, but it's one Merc's engineers have pulled off with the E400 4Matic Cabriolet. Effortless power, a tonne of technology and a comfy, leather-wrapped cabin all make Merc's drop-top E-Class a strong proposition.

It’s hard to look past the value equation of the RX350h Luxury 2WD when comparing it to almost all its competitors. The pricing is on point, but there are some features missing.

However, there are very few (if any) rivals with a true hybrid powertrain (sorry, mild hybrids do not count), so the RX will capture buyers looking for environmental credentials and efficiency without going full EV.

The drive experience is much better than before and it’s all wrapped up in a very stylish package. The Lexus RX should not be ignored.

Elegance. That's the word that springs to mind when you first clamp eyes on the E400 Cabriolet. While the Coupe version has a crouched-over sportiness about its exterior design, the convertible is all about big and boat-like proportions, especially with the fabric roof opened.

Like nearly all drop-tops, the E400 looks best with the cabin open to the elements, and the side profile especially paints a picture of well-heeled wafting, with only the AMG alloys and body styling hinting at the performance on offer under the bonnet.

Inside, expect perfectly executed modern luxury, with soft leather seats, touchpoints that melt under the fingers and a sprinkling of woodgrain trim. All of which feel like old-world luxury, nicely juxtaposed by the huge twin-screen display that dominates the dash.

Across its five generations, the RX has held significant visual appeal - especially the still-handsome second-gen version that was the first RX sold Down Under. The first-gen model skipped Australia.

The new model that launched in 2023 is a clear evolution of the car that came before, but it’s been softened and sharpened in the right areas, giving it one of the most appealing designs in its segment.

The proportions and design elements like the squat stance, unique C-pillar treatment, slimline headlights and nicely sloping roofline give it a sporty look.

In fact, I reckon it might be the best looking Lexus available today - not including the jaw-droppingly beautiful LC coupe and convertible, of course.

The interior is modern and feels like an evolution of Lexus’ previous cabin design - but elevated. The gloss black section of the dash helps here.

Levels built into the dash break up the bulk, but the interior is very grey. It could do with a dash of colour.

The synthetic leather seat trim doesn’t look premium. If you want a more expensive feeling RX, you need to pay more for a higher grade.

It's a two-door, four-seat convertible, so practicality isn't at the very top of its list of strengths.

That said, life is peachy for upfront riders, both of whom will travel in spacious luxury. There are two cupholders hidden beneath a woodgrain cover underneath the climate controls - also home to a power outlet - as well as a clever double-hinged central storage bin that can be opened by either the passenger or driver, and which opens to reveal two USB points.

There's room in the doors for bottles, too, and the entertainment system can be controlled via a touchpad controller mounted above the traditional click wheel - although, to be honest, using it is harder and more time consuming than simply pretending it doesn't exist.

Climbing into the back (and we mean climb - there are no rear doors) is made easier by the fact you can fold and slide the front seats automatically by pulling a lever mounted near the headrest. Once there, though, you'll find space is a little tighter, and you feel weirdly cocooned, owing to the huge raised tunnel that runs through the middle of the cabin, and the low roof line.

There are two cupholders that live in the space where the middle seat would normally go, and there's a little bottle-holder cubby to the left of both backseat riders. There are air vents back there, too, but no temperature controls.

The front doors are huge and really very heavy, requiring considerable heft to open them.

The boot space is predictably a little limited, with 385 litres on offer. There's also a little flip-down separator, which shows you how much room the roof will need to come down, reducing boot space to 310 litres. Speaking of which, the soft-top can be lowered in just 20 seconds, and at speeds up to 50km/h.

One practicality quirk, though. The front (and only) doors are huge and really very heavy, requiring considerable heft to open them, especially if you're parked on a slight angle. Honestly, I was reduced to kind of pushing them open with my foot at times.

The RX is a five-seat only proposition in this generation - the previous model had a seven-seat option - so if you need a third row you can look at the Lexus LM people mover or massive LX 4x4 SUV, or at any number of other three-row lux SUVs like the Volvo XC90 or new Mazda CX-90.

That doesn’t mean the cabin isn’t practical. 

Up front the seats offer excellent comfort levels and ample upper body support, but not a lot of hip support.

Lexus has changed up the door handles for the new RX and it can be complicated - initially.

The interior handles bamboozled every new person that got in my press car over the three week loan. But once you realise it’s a simple push of the thumb on the handle’s thumbpad and a gentle push, it all makes sense.

Lexus calls the electrically activated door handles an ‘e-latch’. Is it tech for tech’s sake? Probably. 

I recently reviewed the Lexus LM and commented on how much I like Lexus steering wheels and that’s true of the RX, too.

It has clearly identifiable controls and feels nice in your hands. Thankfully, the cruise control buttons are housed on the wheel too, so no annoying stalk on the wheel.

There’s plenty of space across the front row so you should avoid the awkward driver-passenger elbow bump on the centre armrest.

Under the armrest is a huge central bin that opens on the driver and passenger side. There’s also a big covered storage nook forward of the shifter and another ledge above that, as well as a sizeable glove box. 

The doors have ample storage room for bottles, but the space is almost too wide. My bottle slid around when driving so I had to lay it down.

The centre console houses two big cupholders with adjustable depth in one of them. Clever touches like this and the central bin add to the appeal.

As with the Lexus LM, I am a fan of the new Lexus multimedia set-up. It has an easy-to-navigate menu along the side, easy wireless Apple CarPlay connection, and visually appealing graphics.

It’s a world away from Lexus’ previous system. That frustrating touchpad is, thankfully, in the bin.

I quite like the gear shifter with its unusual gate and even the indicator feels and sounds premium.

Small rear windows make for a rear three quarter blind spot, but visibility is otherwise good.

On a side note, the RX has very strong air conditioning - perfect for an Australian summer.

Jumping into the second row, there’s plenty of space all around and no shortage of head, leg, knee and shoulder room. Although foot room under the front seats is tight.

As with the front seats, the rear row offers comfortable seating. Kids should be happy back there.

There’s only a small transmission tunnel so middle-seat legroom is good. And in great news for passengers, the rear backrests recline. 

Lowering the 40/20/40 split-fold rear seats for more cargo space is done via a lever on the side of the outboard seats, or by a button in the boot area. There are ISOFIX clips on the two outboard seats.

Other amenities in the second row include map pockets, two USB-C ports, knee-level air vents, climate control, and a pull-down armrest with pop-open cupholders.

Open the power tailgate and you’ll find cargo space of 612 litres with all seats in place, or 1678L with the second row stowed.

That’s a decent amount of space but not class leading. The Mercedes-Benz GLE has 630L and the VW Touareg can swallow 810L.

There’s no under-floor storage because that’s where some hybrid hardware is housed. You will find audio speakers, nice carpet, a cargo blind, two 4.0kg hooks and three top tethers. No spare, only a tyre repair kit.

The range-opening RX350h Luxury 2WD petrol-electric hybrid starts at $86,904, before on-road costs, and for that amount, the standard specification list is healthy. But it doesn’t include everything.

As well as a long list of standard safety gear (see section below), the RX350h comes with three-zone climate control, heated and eight-way adjustable power front seats, electric steering wheel adjust, rain-sensing wipers, a 14-inch multimedia set-up with wired Android Auto and wireless Apple CarPlay, digital radio, sat nav, a 12-speaker audio system, five USB-C (and one USB-A) ports and more.

It is missing a few items, however, that should be standard, such as a head-up display and wireless device charging. Those features are available as part of an options pack - or 'Enhancement Pack' in Lexus speak.

For $5000 more you get those two things and a panoramic sunroof, ventilated seats, a more digital instrument cluster and other goodies. 

You can opt for an all-wheel drive version of the 350h and that adds just over $3500 to the price. If you want the same powertrain but more gear then you’ll need to step up to the $110,575 Sports Luxury.

There’s also the petrol-only RX350 in F Sport and Sports Luxury guise, as well as the flagship RX500h F Sport Performance hybrid that tops out at $124,675.

Looking at the opening price of some of its rivals, Lexus has most of them beat.

The Mercedes-Benz GLE300d starts from $144,900, the BMW X5 xDrive30d is $134,900, Porsche Cayenne starts at $138,700 and the Volvo XC90 B5 Ultimate Bright kicks off from $100,990.

Only the Volkswagen Touareg 170TDI ($89,240) and Jaguar F-Pace P250 R-Dynamic ($83,700) are close on price.

It's a fabulous engine, this twin-turbocharged V6 - even if it doesn't feel quite so lively in Cabriolet form as it does in the hardtop equivalents.

The 3.0-litre unit produces 245kW/480Nm, sending it to all four wheels via a nine-speed automatic transmission, linked to the standard 4Matic all-wheel drive system.

Powering the RX350h is a series parallel hybrid system consisting of a naturally aspirated 2.5-litre four-cylinder petrol engine, a front-mounted motor and a nickel-metal hydride battery. 

Lexus doesn’t provide combined torque outputs for the hybrid, but total power for the system is pegged at 184kW.

This drives the front wheels only via a continuously variable transmission (CVT).

Mercedes claims 7.4L/100km on the combined cycle (but you can expect to be pushing nine litres in real-world conditions), with emissions pegged at 170g per kilometre of CO2.

The 66-litre tank will only accepts 95RON fuel.

The official combined cycle fuel consumption figure for the RX350h 2WD is 5.0 litres per 100 kilometres, with CO2 emissions of 114g/km. You won’t get figures like that in a petrol or diesel competitor.

Over three weeks of mixed city, country, urban and freeway driving, I recorded 6.8L/100km which is not too bad given some of my spirited driving. The trip computer said 7.0L which is close to my figure.

The RX350h takes premium unleaded petrol and has a 65-litre fuel tank, so expect a range of around 950km based on our real-world consumption number.

Sure, the E400 Cabriolet can drive itself, but we’re equally pleased to note that it’s still a lot more fun handling the steering duties yourself.

And that is mostly due to that fabulous engine; quiet and effortless at city speeds, rorty and enthusiastic at pace, and genuinely angry with the drive setting switched to their most hardcore Sport+ mode.

We’ve already spent time in the sedan version, and while this Cabriolet is heavier (1935kg vs 1820kg) and slightly slower to 100km/h (5.5sec vs 5.2sec) it doesn’t immediately feel it behind the wheel, with a similar and satisfying lurch into the future when you plant your foot.

But hard charging is not what this car is about, and the E 400 is at its peachy best when rolling about the city or the ‘burbs with the top down, and the warm summer air washing through the cabin.

In its normal drive settings, the steering is light but engaged, and the ride on offer from the standard air suspension is outstanding, cosseting the cabin from all but the very worst road imperfections, while the torque from the V6 serves up effortless, unobtrusive acceleration.

With the roof up, Merc’s designers have done a stellar job of hiding the fact this thing is a convertible at all. It’s a solid-feeling cabin with the fabric roof fastened, and the cabin is quiet and free from wind noise.

The old RX was competent and even nice to drive but not a patch on the likes of the BMW X5. The new-gen RX improves on that in a big way.

It offers solid acceleration from a standing start. Lexus says 8.1sec from 0-100km/h - without giving you chills. The sportiest RX is the 500h Performance hybrid and that covers the same distance in 6.2sec.

The transition from electric power to petrol propulsion is more evident in this model than it was in the LM350h people mover I tested recently - the RX is a little noisier. The CVT doesn’t help this, offering up an uninspiring engine note.

It is, however, a much more fun car to push into tight bends than the previous RX. It remains reasonably flat in corners, and pulls out of tem with ease, but can’t compare to the dynamics of the dearly departed IS sedan.

The 19-inch tyres have large sidewalls and as a result soak up harsh bumps on the road. The non-adaptive suspension is tuned for better dynamism, meaning the ride quality is on the firm side.

The front-wheel drive RX lost traction for a second on a sweeping uphill section of my drive route, but the electronic traction systems otherwise kept the big SUV in check. 

But around town in urban areas, there is very little to complain about behind the wheel of the RX350h.

The RX comes packed with standard safety gear and the SUV was awarded a maximum five-star crash safety rating from ANCAP in 2022.

Just some of the inclusions are auto emergency braking with pedestrian (day/night), cyclist (day/night) and motorcyclist (day) detection, intersection assist, emergency steering assist, driver monitoring, lane keeping aid and lane departure warning, adaptive cruise control, front and rear parking sensors, blind spot monitor (including stationary) with rear cross-traffic alert and safe exit assist to avoid 'dooring' incidents. 

I must say, Lexus’ (and parent company Toyota’s) driver assistance tech has come a long way.

In the early days of the pandemic during a rare non-lockdown period in Melbourne, I drove from Melbourne to Sydney in the previous-generation Lexus RX200 Sports Luxury.

The lane keeping system and adaptive cruise control were shockingly underdone. The cruise control would simply stop working when you encountered even a slight downhill section. 

Not anymore. The new, smoother lane keeping set-up uses subtle wheel adjustments, unlike the ping pong effect of the previous RX, and the cruise system is now very much in control of the speed.

The Lexus safety suite now operates without too much intervention and is hard to beat among its key rivals.

Expect the usual three-year, unlimited-kilometre warranty, with service intervals pegged at 12 months or 25,000km. Mercedes' capped-price servicing scheme limits maintenance costs to $2280 for the first three years of ownership.

The RX350h is covered by a five-year, unlimited-kilometre warranty, and the servicing schedule is every 12 months or 15,000km.

There’s a capped-price servicing plan lasting five years and it will cost $695 per service. That's significantly less than some rivals like the Mercedes GLE.

The RX is covered by the 'Lexus Encore' loyalty program and includes complimentary service loan cars, fuel offers as well as discounts and other offers with Lexus partners.