Kia Ev4 vs Mercedes-Benz SL63

What's the difference?

An electric sedan is really shrinking the buyer pool, which is why Kia has such gentle expectations for the EV4 in Australia. But it's a lovely driving EV with plenty of perks, and the design alone will brighten up Australia's roadways. For my money, I'd either be going for the cheapest one that's sharp value with plenty of kit, or the flagship GT-Line that gets the big battery and the works in terms of equipment. The Earth for me sits in no-man's land.

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

Note: The author, Andrew Chesterton, is a co-owner of Smart As Media, a content agency and media distribution service with a number of automotive brands among its clients. When producing content for CarsGuide, he does so in accordance with the CarsGuide Editorial Guidelines and Code of Ethics, and the views and opinions expressed in this article are solely those of the author.

The new Mercedes-AMG SL63 4Matic+ is guaranteed to turn heads for decades to come. But there’s enormous design and engineering substance underpinning this car’s undoubted good looks. Stunning performance, superb dynamics and top-shelf safety make this a powerhouse GT to be reckoned with.

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

The slippery-looking unit that adorns this page is the EV4 sedan. There’s also a hatch, but it comes out of Europe, while this one comes out of Korea, and that would likely make the hatch far more expensive than this bad boy. It's under study, apparently, but yet to be confirmed.

Anyway, to steal a hackneyed football analogy, for mine this is a game of two halves. I actually really like the front end. It looks sleek and slippery and there’s a real presence from the swollen arches.

I am, however, a little less sold on this rear end, which looks sharp and blocky and almost like it has been bolted on. Also annoying is the fact that it looks like it should be a liftback, with the boot hinged up above the rear windscreen. But nope, it's hinged below it, so you still get a dinky little opening to squeeze your stuff through.

Kia's international designers are pushing the boat out at the moment, and they deserve credit for making things different. Whether it sinks or swims with the general public, though, will be the real test.

Inside, it's all pretty traditional Kia, with all three models sharing the twin 12.3-inch digital displays, along with the little climate panel in the middle. Kudos to Kia for keeping some physical buttons, too. I'm less sold on the use of some cheap, hard plastics, even in the top-spec cars.

Rather than a strict two-seater, this time around the SL adds the flexibility of ‘+2’ rear seating while the previous 'Vario’ folding hardtop has been binned, the new car returning to a traditional, electrically-folding and weight-saving (-21kg) soft top. 

Mercedes-Benz design chief Gorden Wagener started the new model’s development from a ‘clean sheet’ and Mercedes-AMG says “not a single component comes from the predecessor SL, or any other model such as the AMG GT Roadsters”. 

Always a subjective call, but I think this car’s proportions are just about perfect. The lengthy bonnet with its twin longitudinal ‘Power Domes’, raked windscreen and fat haunches create a wide stance and presence that’s almost impossible to ignore.

Aggression, as with the sinister headlights and 21-inch rims, is subtly combined with soft curves along the flanks and around the rear. Note the seamless door handles.

And it’s not all about aesthetics. Active aero has been integrated into the front apron and retractable rear spoiler. Plus the ‘Z-fold’ roof design does away with the need for a separate cover.

The interior is sub-zero cool with slick screens, an 11.9-inch display covering multimedia and a 12.3-inch unit for instrumentation ahead of the driver, being particular highlights.

Turbine-style air-vents at the leading edge of the split-level dash and alloy trim elements are a tip-of-the-hat to SLs past and the deft mix of large flat surfaces with complex curves oozes design confidence.

At 4730mm long, 1860mm wide and 1480mm tall, the EV4 sits between the Model 3 and the Seal in terms of its outright dimensions. Kia says the EV4's wheelbase and interior packaging has been designed to maximise backseat space, which I must admit, there is plenty of.

Sitting behind my own 175cm driving position, I had miles and miles of leg room, and enough head room, though there is some kind of optical illusion that occurs in the backseat of the EV4 – even though you definitely have enough space, the dark materials of the GT-Line still leaving me feeling a little claustrophobic somehow.

Something else not to be sneezed at is the inclusion of the household-style power plug in the back. My laptop died while I was taking notes on my test, and I plugged it straight in and powered it up. Super handy.

At the back, there is 490 litres of boot space, which is about middle ground. The Seal is more like 400 litres, but the Model 3 offers more.

Sadly the EV4 is yet another EV that does not have a spare wheel of any kind. Instead you have to make do with a tyre repair kit.

In the context of a high-performance GT, practicality is pretty impressive.

At just over 4.7m long the SL is a sizeable machine and much of its lengthy (2700mm) wheelbase is devoted to making the driver and front passenger comfortable.

There’s plenty of space for that pairing and just enough storage to cope with the ‘things’ they’ll typically bring with them.

Door pockets offer enough room for a few odds and ends, although you’ll struggle with even a medium-size bottle unless you’re willing to lay it down horizontally along the top of the aperture.

A handy lidded bin between the front seats doubles as a centre armrest, there are two cupholders under a sliding lid in the centre console and the glove box is a decent size. 

Power and connectivity options run to four USB-C ports, a 12-volt socket and the wireless device charging pad.

Then there are the rear ‘+2’ seats, and Mercedes makes no bones about the fact they’re intended for occasional use only, even suggesting a 1.5m occupant height limit.

And there’s no doubt they offer a handy emergency seat or a fun kids’ zone. Just ask a Porsche 911 Carrera owner how much this kind of seating arrangement increases a sports car’s flexibility.

At 183cm I gave the back seat a crack, which meant sliding the front (passenger) seat way forward with the backrest close to upright. But I squeezed in, and there was just enough legroom for a person in front at the same time. 

With the roof in place there’s the added pleasure of cranking your head over to around 45 degrees. But it’s do-able! 

No storage, adjustable ventilation, or power back there. But that’s fair enough, especially given there are USBs available in the front centre storage box.

Boot volume is 240 litres with the roof up and 213 litres with it folded, which is enough for some light luggage, and not too shabby when you think a Toyota Corolla hatch offers up just 217 litres (with all seats up).

There’s a 12V socket in there, but don’t bother looking for a spare, in the event of a flat your only option is a repair/inflator kit.

Priced at $373,370, before on-road costs, the new SL63 4Matic+ will be battling top-shelf performance soft tops including (in ascending dollar order) BMW’s M850i xDrive Convertible ($307,100), the Porsche 911 Carrera GTS Cabriolet ($386,900) and even exotics like the Lamborghini Huracan RWD Evo Spyder ($422,606). 

Value for money is a relative concept in this part of the market, although equipment highlights include a head-up display (with augmented reality nav), 11-speaker, 650-watt Burmester surround sound audio, ambient lighting (choice of 64 colours), hectares of Nappa leather trim, dual-zone climate control, an 11.9-inch central multimedia screen (running Merc’s latest ‘MBUX’ software), 12.3-inch configurable digital instrument display and 21-inch forged alloy rims.

There’s also the ‘Digital Light System’ built around three high-power LEDs in each headlight, refracted and directed through 1.3 million ‘micro-mirrors’ to create a combined resolution of 2.6 million pixels.

The ‘Neck Scarf’ function is added to the top of the front seats to keep your neck and the back of your head warm as the temperature drops, the heated, ventilated and massaging front seats feature eight-way electric adjustment and three memories, there’s a heated steering wheel, Android Auto and Apple CarPlay connectivity, wireless device charging and more.

Worth noting the big 21-inch rims in a ‘10-twin-spoke’ design are standard issue with an alternate ‘multi-spoke’ pattern available as a no-cost option. 

But if all that’s not enough you can opt for ‘AMG Performance seats’ ($2490) which grip you even more securely but delete the massage function.

Or there’s the ‘AMG Night Package’ ($6990) which adds wheels in matt black (with “high-sheen finish rim flange”), darkened head- and tail-lights, an aero package, black badging, black radiator fins and interior trim elements in black chrome.

Then you can go the whole hog with the ‘AMG Carbon Fibre Package’ ($11,990) which brings the wheels in matt black, exterior carbon elements, carbon mirrors, carbon interior trim and a steering wheel in a combination carbon-fibre and Dinamica (synthetic microsuede).

All EV4 models are front-wheel drive, with a single front-mounted motor producing 150kW and 283Nm, fed through a single-speed gearbox. That’s enough, Kia says, to knock off the sprint to 100km/h in around 7.5 seconds. The Air is the fastest, at 7.4s, while the heavier Earth and GT-Line claim 7.8s. Top speed is a claimed 170km/h.

This new ‘4Matic’ all-wheel-drive SL63 features AMG’s (M177) 4.0-litre twin-turbo V8, superseding the previous rear-wheel-drive SL’s similarly configured 5.5-litre unit.

Hand built by one AMG technician from start to finish, it produces 430kW (around 580hp) from 5500-6500rpm and 800Nm across a broad plateau from 2500-5000rpm.

It’s something of a mechanical masterpiece, and the previous seven-speed auto transmission, driving the rear wheels only, has been replaced by a nine-speed dual-clutch auto (with wet multi-disc start-off clutch) sending drive to all four wheels via Merc’s ‘4Matic’ AWD system.

Let’s talk about range for a moment, because it's bloody impressive. Not quite the best out there, but the furthest any electric Kia has ever travelled between charges.

There are two battery options, a 58.3kWh NCM battery in the Standard Range, and a 81.4kWh unit in Long Range models. The Standard will deliver 456kms in driving range, but the Long Range ups that to 612kms, both on the WLTP cycle. 

The EV4’s 400-volt architecture does slow down charging a little, though, with DC fast charging capped at 128kW. That means going from 10 to 80 per cent in around 30 mins when using the fastest chargers. If you’re using a 50kW charger, it’s up to almost an hour and 20 minutes for the bigger battery, which is a long coffee stop.

Plugged in at home, provided you have an 11kW wallbox, it’ll take just under five and a half hours, or just over seven hours, to go from 10 per cent to fully charged, so an overnight charge no matter the battery size.

Mercedes-AMG’s official fuel economy number for the SL63 on the combined (WLTP) cycle is 13.9L/100km, the 4.0-litre twin-turbo V8 emitting 319g/km of CO2 in the process.

On the roughly 300km launch program we covered urban, B-road and some freeway running, returning an (indicated) average of 17.5L/100km. And that reflects some enthusiastic driving along the way.

The fuel tank requires 70 litres of 98 RON premium unleaded to fill it which translates to a theoretical range of around 500km, dropping to 400km using our real-world number.

I learned something new and exciting (well, to me, at least. You might be very bored) from Kia's ride and handling guru on this launch. And that is that the tuning frequency for common city road imperfections, like bridge expanders, is actually the same as for the bigger, bouncier undulations you get on country roads. And so you can tune to prioritise one or the other, not both.

In real terms, it means a car that feels custom-built for the city, gliding over urban roads with mega comfort (which is exactly what the EV4 does), feels slightly less at home out of town, where there is more obvious movement in the cabin.

Bored yet? Ok, the point is that, while never uncomfortable, the EV4 feels right at home in the city, which is where it's expected to spend most of its time, but weirdly firmer on longer adventures. 

This really is easy, city EV motoring, done well. There's no alienating floatiness to the ride, no lifeless lightness to the steering, it's comfortable, quiet and – despite no headline-grabbing power figures – more than potent enough to get you up and moving.

There's nice weight to the steering, and though the front tyres gave up their grip a couple of times when pushed with some steering lock on, there isn't much in the way of aggressive body roll, and it all feels pretty confidence inspiring. 

The power is most effective from around 10km/h to 80km/h, before the urgency starts to fall away – it's slower to respond at freeway speeds – but that too just leans into its city credentials.

There's really not much to complain about here. It feels well sorted, and quite fun to drive. There is nothing that really stands out as spectacular about the drive experience, but nor is there anything to complain about. It's just really solid motoring, which isn't always guaranteed these days.

I recall driving the AMG SL65 around the backroads of Tassie a few years ago and that twin-turbo V12 monster famously packed 1000Nm of torque, while this car ‘only’ has 800.

But there comes a point where enough is enough… and this is enough!

With maximum torque available from 2500-5000rpm and peak power (430kW) on call from 5500-6500rpm there’s always stupendous acceleration available with a squeeze of your right foot.

Claimed 0-100km/h time is supercar fast at 3.6 seconds, while top speed is a toupe-troubling 315 km/h. And that’s electronically limited!

A typically ferocious engine noise and howling exhaust note accompany rapid progress and shifts from the nine-speed dual-clutch transmission are quick and positive, not to mention especially enjoyable using the steering wheel-mounted paddles.

There are six ‘AMG Dynamic Select’ drive programs from Comfort through to Race, the latter including a Drift Mode, which we didn’t experiment with. Nor did we dip into the ‘AMG Track Pace’ system for circuit-focused mapping and timing

However, far from drifting, the grippy Michelin Pilot Sport 4S rubber (275/35 fr - 305/30 rr) plants the car securely with the all-wheel-drive system and electronic locking rear diff playing their part.

I found the perfect set-up was in the ‘Individual’ mode with the engine, transmission and steering in racier settings and the suspension in ‘Comfort’. The adaptive damping in this configuration mixes smooth ride compliance with sharp dynamic response.

The car’s aluminium space frame chassis is part of a body structure mixing aluminium, magnesium, fibre composites and various strength steels.

Torsional rigidity is claimed to have been improved by 18 per cent and despite the lack of a roof the SL feels tight and solid.

Suspension is by alloy double wishbones front and rear with adaptive damping and active hydraulic anti-roll stabilisation standard (so, no physical anti-roll bars).

At the same time the 4Matic AWD system is able to vary torque distribution up to 100 per cent to the front or rear axle depending on where drive can be put to best use.

The speed sensitive, variable ratio, electronically controlled steering is accurate and turns in beautifully with good road feel. No doubt assisted by electric rear steering able to adjust the angle of the rear tyres by up to 2.5 degrees.

All this adds up to a hugely impressive package that, despite its 1970kg kerb weight, feels agile, athletic and able to attack corners like an overgrown hot hatch, putting its power down with unwavering authority.   

While indecently fast the SL63 can also stop rapidly with the AMG high-performance braking system standard. 

Huge composite ventilated and cross-drilled discs (390mm fr - 360mm rr) are clamped by six-piston fixed alloy calipers at the front and single-piston units at the rear. They wash off speed calmly and consistently with perfect pedal feel.

Even at highway speeds, particularly with the windows up, normal conversation is easy with the roof down. But if you need to raise (or lower) it, the operation takes 15 seconds and is possible up to 60km/h. 

Under the heading of miscellaneous observations, the turning circle is a not insubstantial 12.8m, so beware in the car park.

A front axle lift function is a welcome standard feature, raising the car’s nose 30mm with the press of a button. And lift locations are stored in GPS data, so the car will subsequently remember to lift itself at the same place, even if you don’t! 

Heating and cooling for the front seats combined with the heated steering wheel and Air Scarf neck warming makes winter top-down driving a pleasure.

The digital instrument display is not only crystal clear, it can be changed through multiple configurations, including a tunnel-like graphic for engine revs as well as specific readouts for speed, g-force, the lot.

At the same time, the central media screen’s angle can be adjusted to better cope with reflections and the windscreen wiper system Merc calls ‘Magic Vision Control’ channels fluid along the wiper arms onto the rubbers, which isn’t new, but works spectacularly well here.  

No independent ANCAP safety assessment at this stage but the SL63 is fitted with the ‘Driving Assistance Package Plus’ which includes a heap of active (crash-avoidance) tech including AEB (with pedestrian detection), active cruise control, lane keeping assist, lane change assist, traffic sign assist, ‘Active Traffic-assist’ and ‘Active Steering Assist’. 

There’s also tyre pressure monitoring and the ‘Active Parking Assist with Parktronic’ self-parking system supported by a 360-degree camera view and multiple sensors. 

If a crash is unavoidable the airbag count runs to eight, including side bags for rear occupants. There are ISOFIX anchor points for child seats or baby capsules in the two rear and front passenger seat positions. And an active bonnet is designed to reduce injuries in the case of a pedestrian impact.

Kia ownership proposition is simple, and pretty strong. You get a seven-year warranty no matter how far you travel, an eight-year warranty for the high-voltage systems, again no matter how far you travel, and capped-price servicing. Pre-paying your service costs will set you back $688 for three years, just over $1300 for five years, or just under $2000 for seven years.

The SL63 4Matic+ will be covered by Mercedes-AMG’s five-year/unlimited km warranty, with roadside and accident assistance included for the duration, both of which are expected in this category. 

Maintenance intervals are 12 months/20,000km, and a fixed-price service plan lists an average of $1583 for each of the first three visits to the workshop. Not exactly small change, but not unheard of in this part of the market.