Mercedes-Benz E400 vs Lexus IS300

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.

The new-look Lexus IS takes several steps forward over its predecessor - it’s safer, smarter, sharper to look at and still pretty well priced and equipped.

It is feeling its age inside, and the competition has moved on in terms of engines and EV tech. But even so, if I was buying a 2021 Lexus IS, it would have to be the IS350 F Sport, which is just the most fitting version of this car, though the IS300h Luxury does have plenty to like for the money, too.

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.

You either get the Lexus look or you don’t, and I think this latest version is possibly more agreeable than the IS in years gone by.

That’s partly because the brand has finally done away with the odd spider-eyes twin-section headlights and daytime running lights - now there are more traditional headlight clusters, which look a lot more resolved than before.

The front end still features a bold ‘spindle’ grille, which gets different treatment depending on the grade, and the front, to my eye, looks better than before but still very much stuck in its ways. 

At the side you’ll notice the giveaway windowline hasn’t changed, despite the chrome trim line having broadened as part of this facelift, but you can tell the haunches have muscled up a bit, with the new IS now 30mm wider overall, and the wheel sizes are 18s or 19s, depending on the grade.

The rear accentuates that width, with an L-shaped lighting signature now spanning the entire re-sculpted boot lid, giving the IS a pretty tidy rear end design.

Overall dimensions for the IS are 4710mm long, making it 30mm longer nose to tail (on an unchanged 2800mm wheelbase), while it now spreads across 1840mm (+30mm) and is 1435mm tall (+5mm).

The exterior changes really are impressive - I think it is a more purposeful but also more pleasant looking car now than it ever has been in this current generation. 

The interior? Well, there’s not a whole lot to talk about in terms of design changes, aside from the repositioned and larger media screen - which sits 150mm closer to the driver because it’s now a touchscreen with the latest smartphone mirroring tech. Otherwise it’s a carryover affair, as you can see from the interior pictures.

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 interior design of the IS, as mentioned, hasn’t changed dramatically, and it is starting to feel old compared to some of its contemporaries.

It’s still a nice place to be, with comfortable front seats with electric adjustment and heating across all grades, and cooling on many variants, too. 

The new 10.3-inch touchscreen media system is a nice unit, and means you can essentially do away with the silly trackpad system that still resides near the gear selector, so you may still end up bumping it accidentally. And the fact the IS now has Apple CarPlay and Android Auto (though neither are wirelessly connectable) does further its appeal on the multimedia front, as does the standard 10-speaker Pioneer stereo - though the 17-speaker Mark Levinson unit is an absolute blinder!

The centre stack below the media screen retains a CD player, and still has the electromagnetic temperature adjustment sliders as well. That part of the design is dating it just as much as the transmission tunnel console area, which looks a bit out of touch by modern standards, though still incorporates a pair of cup holders and a reasonably large centre console bin with soft armrest padding.

The front doors feature trenches with bottle holders as well, while in the rear doors there is still no drink storage - a carryover annoyance from the pre-facelift model. However, the middle seat in the back doubles as an armrest with pop-out cupholders, and there are rear air vents too.

Speaking of that middle seat, you wouldn’t want to sit in it for long, as it has a raised base and uncomfortable backrest, plus there’s a huge transmission tunnel intrusion eating into leg and foot space.

Outboard passengers also miss out on toe room, which - for my size 12s - is an issue. And it’s hardly the roomiest second row in this class for knee room and headroom, as my 182cm frame was a touch squished behind my own driving position.

Children will be better catered for in the back, and there are two ISOFIX anchorages and three top-tether attachment points for baby seats.

The boot capacity varies on the model you buy. Choose an IS300 or IS350 and you score 480 litres (VDA) of cargo capacity, while the IS300h has a battery pack that robs it of some boot space, with 450L available. 

The updated 2021 Lexus IS range has seen a number of pricing changes, and a reduction of variants, too. There are now five IS models available, down from seven prior to this update as the Sports Luxury model has been axed, and you can only get the IS350 in F Sport trim now. However, the company has expanded its “Enhancement Pack” strategy across the different variants.

Opening the range is the IS300 Luxury, which lists at $61,500 (all prices listed are the MSRP - not including on-road costs, and are correct at time of publishing). It has the exact same equipment as the IS300h Luxury model, which is $64,500, and that ‘h’ stands for hybrid, which will be detailed in the engines section. 

The Luxury trim is equipped with items such LED headlights and daytime running lights, 18-inch alloy wheels, proximity keyless entry with push-button start, a 10.3-inch touchscreen multimedia system with satellite navigation (including live traffic updates) and Apple CarPlay and Android Auto smartphone mirroring tech, plus a 10-speaker sound system, eight-way power-adjustable front seats with heating and memory settings for the driver, and dual-zone climate control. There’s also auto headlights with auto high beam, rain sensing wipers, power steering column adjustment, and adaptive cruise control.

Indeed, there’s a raft of safety technology included - more on that below - and there’s also a number of Enhancement Pack options.

Luxury spec models can be equipped with a choice of two Enhancement Packs: the $2000 Enhancement Pack adds a sunroof (or moonroof in Lexus speak); or Enhancement Pack 2 (or EP2 - $5500) further adds 19-inch alloy wheels, a 17-speaker Mark Levinson sound system, cooled front seats, high-grade leather-accented interior trim, and a power-operated rear sunshade.

The IS F Sport trim line is available across the IS300 ($70,000), IS300h ($73,000) or the V6-powered IS350 ($75,000), and it adds a number of additional features over the Luxury grade.

As you can probably tell, F Sport models get a sportier look, with a body kit, 19-inch alloy wheels, standard fit adaptive suspension, sports front seats with cooling, sports pedals, and five drive modes to choose from (Eco, Normal, Sport S, Sport S+ and Custom). The F Sport grade also includes a digital instrument cluster with an 8.0-inch display, as well as leather-accented trim, and scuff plates.

Buying the F Sport grade allows customers to add further goodies by way of the Enhancement Pack for that grade, which costs $3100 and includes the sunroof, 17-speaker sound system and rear sunshade.

What’s missing? Well there’s no wireless phone charging in any grade, and no USB-C connectivity either. Note: the spare wheel is a space saver in the IS300 and IS350, but there is only a repair kit in the IS300h as there are batteries where the spare wheel would go.

There’s no go-fast IS F model sitting at the top of the tree here, nor is there a plug-in hybrid to compete against the circa-$85K BMW 330e and Mercedes C300e. But the fact the IS models all come in below $75K means it’s a pretty decent value proposition.

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.

The engine specs depend on the powertrain you choose. And at a glance there’s no variance between the earlier version of the IS and the 2021 facelift.

That means the IS300 model still runs a 2.0-litre turbocharged petrol motor producing 180kW of power (at 5800rpm) and 350Nm of torque (at 1650-4400rpm). It has an eight-speed automatic transmission, and like all IS models, it is rear-wheel drive (RWD/2WD) - there is no all-wheel drive (AWD/4WD) model here.

Next up the spectrum is the IS300h model, which has a 2.5-litre four-cylinder Atkinson cycle petrol motor teamed to an electric motor and nickel metal hydride battery pack. The petrol engine is good for a 133kW (at 6000rpm) and 221Nm (at 4200-5400rpm), and the electric motor produces 105kW/300Nm - but the combined total maximum power output is 164kW, and Lexus doesn’t provide a maximum torque figure. The 300h model runs a CVT automatic transmission.

The big horsepower offering here is the IS350, which runs a 3.5-litre petrol V6 engine, producing 232kW of power (at 6600rpm) and 380Nm of torque (at 4800-4900rpm). It runs an eight-speed auto.

All models have paddle-shifters, while the two non-hybrid models have seen tweaks to the transmission software that is said to “estimate driver intentions” for better enjoyment. 

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.

There’s still no diesel model, no plug-in hybrid and no full electric (EV) model - which means that while Lexus was at the forefront of electrification with its so-called “self-charging” hybrids, it is falling behind the times. You can get plug-in versions of the BMW 3 Series and Mercedes C-Class, and the Tesla Model 3 plays in this space in full-electric guise.

As for the fuel-sipping hero of this trio of powertrains, the IS300h is said to use 5.1 litres per 100 kilometres on the combined cycle fuel test. In reality, our test car’s dashboard showed 6.1L/100km across a mix of driving.

The IS300 with its turbocharged 2.0L engine is next best for fuel use, claiming 8.2L/100km. On our short launch drive of that model, we saw 9.6L/100km on the dashboard.

And the full-fat IS350 V6 petrol claims consumption of 9.5L/100km, while on test we saw 13.4L/100km.

The emissions for the three models are 191g/km (IS300), 217g/km (IS350) and 116g/km (IS300h). All three are Euro 6B compliant. 

Fuel tank capacity is 66 litres for all models, meaning your mileage range for the hybrid model could be considerably longer.

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.

With the engine at the front and drive to the back, it has the ingredients for a pure driver’s car, and Lexus made a bit of a big deal about the new-look IS being more focused thanks to chassis adjustments and track width improvements - and it does feel a pretty nimble and tied-down car in the twisty stuff. 

It is competent at stitching together a series of corners, and the F Sport models are particularly adept. The adaptive suspension in those models includes both anti-dive and anti-squat tech, which is designed to make the car feel solid and flat on the road - and it does, thankfully without feeling twitchy or uncomfortable, with good suspension compliance even in the most aggressive Sport S+ drive mode.

The 19-inch wheels on F Sport models are fitted with Dunlop SP Sport Maxx rubber (235/40 front, 265/35 rear) and there’s plenty of tarmac tenacity.

The grip from Luxury-spec models on 18s could be better, with those Bridgestone Turanza tyres (235/45 all around) proving not quite the most enthralling. 

Indeed, the IS300h Luxury I drove felt very different in character to the F Sport IS300 and 350 models. It was surprising how much more of a plush-focused model the Luxury grade feels, and likewise it wasn’t as impressive in dynamic driving due to the tyre grip and less-enthusiastic drive mode system. The non-adaptive suspension is a touch more jittery too, and while it’s not to the point of discomfort, you might expect better for a car on 18s.  

Across all models the steering is accurate and direct enough, with predictable response and decent feel to the driver’s hands for this electric power steering setup. The F Sport models have even further retuned steering for “an even sportier drive experience”, though I found at times it could feel a little numb for rapid changes of direction. 

As for engines, the IS350 is still the pick. It has the best zest, and feels the most fitting powertrain for this model. It sounds good, too. The auto transmission is pretty clever, there's easily enough pulling power, and it's probably going to be the last of the non-turbo V6s in Lexus's line-up when this cars life-cycle is up.

The IS300's turbo engine was the most disappointing, lacking some urge and constantly feeling bogged down by turbo lag, transmission confusion, or both. It felt underdone in enthusiastic driving, though in dull day-to-day commuting circumstances it came across as more acceptable, though the remapped transmission software was far less impressive in this application than in the IS350.

The IS300h was a lovely, quiet and refined experience all around. It’s the one you should go for if you don’t really care about all that go-fast stuff. The powertrain is proven, it accelerates with nice linear delivery, and at times it’s so hushed I found myself looking down at the instrument cluster to see if the car was in EV mode or if it was using the petrol engine. 

Safety equipment and technology has been upgraded for the IS 2021 model range, though it is expected to carry over its existing five-star ANCAP crash test rating from 2016.

The facelifted version scores auto emergency braking (AEB) with day and night pedestrian detection and daytime cyclist detection (from 10km/h to 80km/h) and car detection (10km/h to 180km/h). There’s also all speed adaptive cruise control with low speed following.

The IS also has lane keeping assistance with lane departure warning, lane trace assist, a new system called Intersection Turning Assist which will brake the car if the system judges the traffic gap isn’t big enough, and there’s also road sign recognition.

Plus the IS has blind-spot monitoring on all grades, as well as rear cross-traffic alert with auto braking (below 15km/h).

And beyond that, Lexus has added new Connected Services features, including an SOS call button, automated collision notification if an airbag deploys, and stolen vehicle tracking. 

Where is the Lexus IS built? Japan is the answer.

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.

On paper, Lexus’s ownership offer isn’t quite as enticing as some other luxury car brands - but it has a strong reputation for blissful ownership.

The Lexus Australia warranty period is four years/100,000km, which is better for duration than Audi and BMW (both three years/unlimited km) but not as accommodating as Mercedes-Benz or Genesis, each of which offer five-year/unlimited km warranty.

The company has a three-year capped price servicing plan, with maintenance every 12 months or 15,000km. The first three visits cost $495 each. That’s okay - but Lexus doesn’t offer free servicing like Genesis, and nor does it offer prepaid service plans - for three to five years for a C-Class, and five years for Audi A4/A5, for instance.

There is complimentary roadside assistance for the first three years, too.

That said, the company has its Encore ownership benefits program that allows a number of experiences and deals, and the service team will collect your car and return it, leaving you with a loan car if you need it.