Mercedes-Benz S-Class vs MG Im5

What's the difference?

Mercedes-Benz set out to restore the S-Class' place amongst the greatest sedans in the world.

In the heavily-optioned, near-$250K-plus S450 as well as the extended S450L at $300K as tested (the sweet spot of the range for now), we reckon the Germans have succeeded, pushing safety, comfort and technology boundaries, in a package that is true to the heritage of the series.

Tax-fuelled sky-high prices will certainly keep the S-Class niche in Australia, but the car is more than good enough to dominate its tiny corner of the upper-large luxury car sphere.

The best new car in the world? We reckon it's highly likely. Mission accomplished, Mercedes.

The MG IM5 Performance is fast, comfortable, quiet and super refined. Putting some minor spec and active safety niggles to one side, it offers the features, tech and price to match it with its well-credentialled and already popular mid-size EV sedan competitors. Is there room for one more? We think there should be.

Most Mercedes models have followed the Russian Doll-style cookie-cutter styling theme, and the heavy family look continues with the W223.

Still, the flush door handles do add a touch of Tesla-esque modernity, while the elegant silhouette and clean lines are in keeping with the luxury aspirations. Larger in every dimension compared to the old W222, the S450 is some 71mm-longer in wheelbase (3106mm) than before while the LWB's has stretched out by 51mm (3216mm), benefiting proportions as well as interior packaging.

AMG-branded wheels look sporty but – in the S450 at least – they're perhaps a tad too gangster. A set of flush alloys would give it a more-modern and techier appearance, in our opinion.

Overall, however, the S-Class ‘7' possesses the prerequisite richness of design. It isn't as bold and mould-breaking as models like the W116 were back in their day, but the styling is still a success.

By the way, the latest S-Class is the first Mercedes to employ the MRA2 longitudinal platform, which is rich in lightweight steels (50 per cent aluminium), is correspondingly stronger than before but also 60kg lighter.

With a drag co-efficiency rating as low as 0.22Cd on some overseas grades, the W223 is one of the most aerodynamic production vehicles in history.

Playing spot the straight line on the outside of the MG IM5 is like an automotive design version of Where’s Wally? There aren’t many, in the midst of an unrelentingly curvaceous exterior treatment.

At close to five metres long and two metres wide the IM5 is appreciably longer (+211mm), a little wider (+27mm) and a bit taller (+33mm) than a Tesla Model 3. Think BMW 5 Series in terms of overall size.

And the soft-form shape is functional; the swoopy liftback boasting an ultra-slick 0.24 drag coefficient.

That said, I’m not convinced by the ‘Periscopic’ cameras informing the driver assistance systems from the front guards. They scream tacked-on afterthought. But a touch-only initial opening function for the flush door handles is cool and makes life easier.

The curves continue inside with soft-padded surfaces around the dash and doors, but the straight edge obviously came out for the 10.5-inch central media screen and vast 26.3-inch upper display. There are next to no buttons; even exterior mirror adjustment is directed from the screen to a multi-function steering wheel control.

System software (powered by a Qualcomm ‘Snapdragon’ chip) is lightning fast with a two-finger up and down swipe shortcut function on the central screen for ventilation and other functions.

The interior is light and bright thanks to the enormous panoramic sunroof. It’s been fine in cooler winter conditions during this test but it could be interesting to revisit in the heat of an Aussie summer

There are two interior colour schemes available - the ‘Highland Grey’ of our test car or ‘Dover Beige’ for those brave enough to live life with the threat of scuff marks on your shiny new car’s glamorous but vulnerably light interior.

For the beginning of our day with the S-Class, we were chauffeured from home to a mansion in Kew, a blue-chip Melbourne suburb. Our heavily-optioned S450L featured most of the aforementioned extras – including the Business Class Package and Rear Entertainment Package – and the experience was predictably, sumptuously memorable.

Reclining individual rear seats with easy-reach tablets, armrests offering access to all multimedia and available climatised and massaging cushions and backrests... we're no longer in our normal ride, Toto.

Yet, all these trinkets and gizmos are mere add-ons, that can turn a stretched Caprice into a flash hen's night carriage if enough money and glitz is thrown at it.

No, the new S-Class must impress in an altogether less tangible and more philosophical manner, involving all the senses, and not just what we see, hear and touch. It must appeal beyond the superficial. Otherwise, it is not a large Mercedes-Benz luxury sedan in the classic manner.

This is a Herculean task for the Stuttgart designers and engineers. By and large, though, the Three-Pointed Star has succeeded in achieving something special.

In its perception of peerless quality and engineering, the W223 is striving to move forward and look back simultaneously to the glory days of the seminal W126 (1980-1991). This is through meshing traditional virtues like solidity and quality materials while dazzling its passengers with technology that is still friendly enough to want to enhance your experience.

You can sink into the soft lounge seats, watch the world pass by silently outside and never be aware of the road underneath or the engine ahead. Double glazing, exquisite and aromatic fabrics and materials and lush tactile surfaces work their magic inside the car, while an airtight and aero body, solid platform, air suspension and a muted yet muscular powertrain all do their thing underneath. The atmosphere is special and rarefied. That's what an S-Class needs to be and that's what is happening in our $299,000 (as tested) S450L.

The same more-or-less applies up front, as the same trim, leather, wood and technology surrounds the driver and passenger. The spectre of the car that is surely The Car of the Last Decade – Tesla's Model S – is evident in the portrait touchscreen and sparse, almost wallflower dashboard design and layout. No big imposing architectures here.

Yet, while the American upstart actually takes stuff away, the S-Class packs the cabin with subtle features that – like when the planes stopped flying last year and the birdsong subsequently returned – only become obvious once the cabin's design simplicity clears all the white noise for you to be in a better frame of mind to enjoy them.   

Take the haptic interface, for example, as it is perhaps the best we've experienced; the sense of well-being garnered from the cumulative effects of profound seat comfort (the massaging function was never switched off), cocooning micro climate environmental control, orchestral levels of audio entertainment and the theatre of light and vision performed by the two available screens; it is an automotive experience like no other. And the eye-tracking 3D-effect navigation set within the electronic instrumentation. No need for cinematic glasses to get the effect. The driving position itself, by the way, is also first class.

Room to stretch and grow for sure, and in every direction. But room for improvement? You betcha.

Your tester had a headache after a little while staring at that woozy 3D map. The central vents – four at the front, two in the rear – look and feel cheap, leaving us mentally redesigning them; they are frightfully out of place here; the carryover column-stalk auto lever should have been binned in 2005. And, even though the digital instruments have a number of options, none are elegant enough for the S-Class. That's an especially subjective criticism, clearly, but one that – in the context of classic Mercedes luxury sedan contenders – is justified given how timeless the Bruno Sacco era of Daimler design was. Look him up, kids.

Still, after a couple of hours behind the wheel, with our senses reset to calm, it is obvious that the S-Class cabin is a unique and wonderful place – as it should be at a cool quarter-of-a-million dollars.

Job done.

PS At 550 litres (20L more than before), the boot is massive and luxurious enough to sleep in.

There’s plenty of breathing room up front and in terms of storage one of the first things worth calling out are the long but relatively narrow door bins. No good for anything above unusually slender bottles, even if they’re lying down.

No conventional glove box in the dash, but there is a large lidded box (cooled and heated) between the seats that doubles as a centre armrest. It’s supplemented by a big stowage area underneath the flying buttress style centre console.  

There are two cupholders in the centre console as well as a wireless device charging pad in front of them with a vaguely phone-shaped oddments bin alongside it.  

Move to the rear and the IM5’s 75mm wheelbase advantage over the Tesla Model 3 is clear. Heaps of knee and headroom for me at 183cm sitting behind the driver’s seat set to my position. 

But… the seat sits low which pushes your knees up into the air to the point where my thighs are not contacting the seat cushion. Even though the rear seat reclines to a certain degree it’s a problem compounded by a chronic lack of room for your toes under the front seat. Awkward.

There are map pockets in the front seatbacks, modest bins in the doors and a fold-down centre armrest with two cupholders. Adjustable ventilation in the rear of the front centre console always makes life in the rear seat more pleasant.

The car also houses ‘Strong Magnets’ at various points around the cabin and boot, with a configurable adapter able to lock a phone or tablet into place for the entertainment of, in our case, back seaters. 

Speaking of devices for entertainment, there are two USB-C sockets and a 12-volt outlet in the front and another USB-C and 12V in the back, so charging isn’t an issue. 

The IM5 is a liftback so the boot aperture is generous and a capacity of 457 litres with the rear seats up is decent for a car of this size, although that’s less than the Tesla Model 3 (594L) which has an additional well under the floor. 

Still, enough room for the largest (124L) and smallest (36L) suitcases from the CarsGuide three-piece luggage set with some room to spare.

The power tailgate can be operated hands-free via the key or an always welcome under bumper kick function.

Volume expands to 1290 litres with the rear seats folded and there’s a modest 18-litre ‘frunk’ under the bonnet.

The bad news is a repair-inflator kit rather than a physical spare wheel, but the better news is the IM5 Performance can tow a 1500kg braked trailer (750kg unbraked).

The IM range also features the ‘MG iSmart’ app allowing remote control of various functions including charging, checking vehicle location and route planning. 

At $80,990, drive-away, the IM5 Performance sits at the top of a three-grade line-up that starts with a 75kWh RWD Premium model at $60,990, followed by a mid-spec 100kWh RWD Platinum for $69,990, both drive-away.

Its most prominent competitor is arguably the Tesla Model 3 Dual Motor AWD ($80,900), with others including the BYD Seal Performance AWD ($68,798), Hyundai Ioniq 6 AWD Epiq ($86,500) and Polestar 2 Long Range Dual Motor Performance ($80,380).

Worth noting, too, the IM6 range - essentially the same car with a taller SUV body - has the same model walk-up and identical pricing.

Once you’ve crossed the $80K threshold it’s fair to expect a decent basket of standard fruit and aside from the dynamic and safety features we’ll get to shortly, the IM5 Performance comes to the party.

Highlights include a double-glazed panoramic roof, power-adjustable (12-way driver, six-way passenger) heated and ventilated front seats (also heated in the rear), dual-zone climate control, 20-speaker audio (with digital radio), 256 colour ambient lighting, a power tailgate (with hands-free function) and 20-inch alloy rims.

There’s also adaptive cruise control, a heated steering wheel, wireless Android Auto and Apple CarPlay, LED headlights, keyless entry and start, wireless device charging (50W), a 10.5-inch central control screen and a sweeping 26.3-inch upper screen; the right side for instrumentation and car data, the (touch-sensitive) left side for multimedia and other onboard functions.

There’s more and it’s clear this car at least matches or betters its direct competitors for included equipment.

Where are the V8s?

Right now, the only W223 you can buy is powered by an all-new 2999cc 3.0-litre in-line direct-injection six-cylinder turbo petrol engine dubbed the M256, complete with double overhead cams, an electric compressor intercooler and assistance from a 48-volt mild hybrid system and integrated starter-generator, adding 16kW and 250Nm to the 270kW of power at 6100rpm and 500Nm of torque from 1600-4500rpm.

The 9G-Tronic torque-converter automatic transmission and 4Matic all-wheel drive system combination is a first for the S-Class in Australia.

Top speed is limited to 250km/h, while the 0-100km/h sprint-time takes just 5.1 seconds in both models. Impressive for a two-tonne-plus luxury limo.

The MG IM5 Performance is powered by an electric motor on each axle - the rear (372kW/500Nm) more powerful than the front (200kW/300Nm), for overall outputs of 572kW (that’s close to 770hp) and 802Nm of pulling power.

The official term for that amount of grunt is… a lot. And we’ll get to what it means on the road in the Driving section shortly.

With the aid of the mild-hybrid system, the S450 returned a combined average of an impressive 8.2 litres per 100km, which translates to 187 grams of carbon dioxide emissions per kilometre. 95 RON premium unleaded (or higher) is recommended. In the urban run it consumes 11.3L/100km (11.5 for S450L), and just 6.4L/100km (6.5 for S450L) in the extra-urban result.

At 76 litres, the fuel tank will allow a combined average range of about 927km between refills.

The MG IM5 Performance features an 800-volt electrical architecture which means the 100kWh NCM battery can accept a DC peak charge of close to 400kW.

Only snag is the highest you’ll currently find in Australia is 350kW. But even at that rate you’ll still be looking at a 30-80 per cent charge in just over 15 minutes. Maximum AC charge rate is 11kW.

Claimed range is 575km (WLTP) which is less than the Tesla Model 3 Dual Motor AWD at 629km.

Over a week of city, suburban and some freeway running we saw average energy use of 20.6kWh/100km which is on the high side for an EV of this size but maybe not for one with this kind of performance potential. 

In former times, as the Germans say, a ‘450' on the boot indicated V8 power. In the W116 S-Class era it was one of the world's most evocative badges when ‘SEL' was also attached.

As mentioned earlier, though, it's the M256 3.0-litre turbo-petrol with a 48-volt ‘mild hybrid' electrical system that's doing the driving, to all four wheels. The real V8 W223 will probably surface later this year or in early 2022 with the S580L flagship. Bring it on.

This is not to say that S450 isn't good enough. With that electrified assistance, the blown straight six is smooth and swift off the line and rapid as the auto seamlessly steps up through all nine gears. Because it's so hushed and refined, it doesn't feel 5.1s to 100 clicks quick, but watching the speedo says otherwise – acceleration is assertive and strong right up way past the legal speed limit.

All that's missing is the burbling soundtrack of a classic Benz bent-eight. Oh well. Outstanding economy is a price we're literally willing to pay in lieu.

Even more impressive is the S450's ability to hustle along mountain roads like an overgrown sports sedan.

Now, for Australia, all S-Classes are fitted standard with an adaptive ‘Airmatic' air-suspension set-up, including air springs and self-levelling tech. In Comfort up to 60km/h, the ride height can be raised by 30mm, or lowered by 10mm under the standard 130mm baseline in Sport at any velocity, while in Sport+ it falls another 17mm.

With that in mind, yes, the standard air suspension performs a magnificent job smothering out most surface imperfections around town. Yet its real other party trick is to tighten up the chassis when corners get interesting and Sport mode is selected. Aided by progressively weighted and reassuringly responsive steering, the Mercedes tips into turns with precision and poise, slicing through with virtually no discernible body lean or understeer.

Now, we're not talking a leisurely drive on rural highways here, but Healesville's famous Chum Creek Road, where even a Porsche Cayman would feel like it's had a strenuous dynamic workout. The S-Class can be hurried along with confidence and finesse, displaying outstanding handling and roadholding for a 5.2-metre long limo. And the fact that the ride quality only suffers marginally when the red horns are out is all the more remarkable.

Back in the cut-and-thrust of inner-city peak-hour traffic, the Benz in Comfort mode continued to reveal its driver-orientated yet passenger-focused twin-personalities, zipping in and out of gaps while remaining comfy and composed inside.

Only when parking in tight spots are you truly aware that the W223 is longer than a Mazda CX-9. The optional four-wheel-steering system is claimed to slash the turning circle to A-Class hatchback levels. 10.9 metres is the claim.

The 2021 S-Class never ceases to amaze and delight.

First things first, the IM5 Performance is supercar fast. This 2.3-tonne five-seater blazes from 0-100km/h 3.2 seconds and with its dual motors combining to produce 572kW/802Nm, eye-widening performance always resides underneath your right foot.

But it’s not all about straight line speed. Ride comfort is excellent. Underpinned by an all-new platform, the IM5’s suspension is by double wishbones at the front and multi-links at the rear. But the key to its bump and rut smoothing ability is air suspension and ‘continuous control’ active damping.

Fold in double-glazing on the full-length glass roof and side windows, as well as active noise cancellation and you have a serene interior environment at any speed. Also worth noting the front seats are great; as grippy as they are comfortable.

Not only that, despite its relative heft, this mid-sizer steers well, too. Not the last word in road feel but it points accurately and the standard rear steering helps with prompt (but never jerky) cornering turn-in. Flick to ‘Sport’ mode and the IM5 is up for some enthusiastic running.

The rear wheels can turn up to 12 degrees in the opposite direction to the fronts at slow speed, which makes for a usefully tight 10-metre turning circle. But above that, at lesser angles, it adds extra stability and decisiveness in the way the car steers through even tight, twisty sections.

Rubber is top-shelf Pirelli P Zeros on 20-inch alloys (245/40 fr - 275/35 rr) and it grips hard, especially in the wet weather over much of the test period. Braking is solid, as it needs to be, with ventilated discs all around and four-piston callipers at the front. 

No adjustable regen braking but you can feel the ‘Cooperative Regenerative Brake System’ (CRBS) doing its thing when you lift off the accelerator. 

The physical rear view is modest thanks to the slope of the back window reducing its functional area for the driver to that of a 1950s VW Beetle. Even the interior rear-view mirror is tiny and folds up into a recess in the headliner if you’d prefer life without it.

But that’s where a rear camera view popping up on the upper screen display (accessed via the right-hand steering wheel click control) comes in handy. Side camera views are also available as is a 360-degree overhead view, which makes parking straightforward.

If you need more parking help there are various self-parking modes including a nifty ‘Curbside’ function that will realign the car hands-free if you’re parallel parked too far out from the kerb.

In a similar vein, a ‘Rainy Night’ mode projects left and right rear views onto the main screen using AI to enhance clarity and highlight pedestrians and cars.

Overall the ADAS (Advanced Driver Assistance Systems) are relatively unobtrusive but we found ourselves switching off the incessant overspeed chime that sounds for 10 seconds if you creep over the indicated speed limit, even when the system has misfired on the correct speed. For example, 40km/h school zones on a Sunday.

The over-zealous driver distraction warning also occasionally issued a visual and audible slap on the wrist when I was looking straight ahead. Tellingly, there’s a specific quick screen for turning both these functions off, but it kinda defeats the purpose of having them in the first place.

We also found the adaptive cruise control to be hesitant in multi-lane environments, reducing speed occasionally because the system seemingly believed a car was set to merge, when it wasn’t.

No independent ANCAP safety assessment at this point but there’s a full suite of active safety tech onboard including AEB, lane departure warning, blind spot detection, rear cross-traffic alert & braking, forward collision warning, lane-change assist, tyre pressure monitoring and heaps more. And we touch on how it all operates in the Driving section above.

There are no less than nine HD cameras, 12 ultrasonic sensors and three millimetre-wave radars on duty.

If a crash is unavoidable there are seven airbags including full-length side curtains and a front centre bag. Multi-collision brake also minimises the chances of subsequent impacts after an initial crash. There are also three top tether points and three ISOFIX child seats anchors across the second row.

All right on the pace for this part of the market and the IM5’s competitive set.

Unlike many luxury brands that persist with a sub-par three-year warranty, Mercedes-Benz offers a five-year/unlimited kilometre warranty.

Intervals are every year or 25,000km, with a capped price service plan starting at $800 for the first year, $1200 for the second year and $1400 for the third year, totalling $3400. Alternatively, there is a Service Plan starting at $2700 for the first three years (saving $700 from the normal capped-price service plan), $3600 for four years and $5400 for five years.

The MG IM5 Performance is covered by a seven-year/unlimited km warranty, which is a plus, but the catch is it’s conditional on authorised dealer servicing. Go elsewhere and the term drops to a more common five years/unlimited km. The drive battery is covered for eight years/160,000km, which is the norm in the Aussie market

Servicing is required every 12 months or 20,000km with charges averaging $586 per workshop visit for the first five years, which is on the high side for an EV, even at this price point, the average bumped up by a more than $1400 doozy at year four.

MG IM models are sold (with service available) through all of MG’s 100-plus dealerships across the country, so no concerns there.