Mercedes-Benz CLA-Class vs Audi S8

What's the difference?

The broadening of the CLA’s scope in this third-gen version puts it a step ahead of key rivals and raises the compact sedan’s prominence in the three-pointed star’s local line-up. Its combination of quality design, performance and efficiency is compelling. And we’ll drive the battery-electric version as soon as it lands.

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

The S8's existence is a source of joy for me because it's not a huge SUV. Yes, it's a huge sedan but it's a reminder that the technological flagship is alive and well, at least in Germany. And the important thing about these cars is the way the toys filter down through the rest of the range. That used to take years but we're seeing this cool stuff a lot more quickly, right down to the A1.

The S8 punches, and punches hard in this rarefied part of an already shrunken section of the market - the twin-turbo V8 matches its German rivals, it's lighter and it's as well-stacked as any of the three. What it doesn't do, however, is shout about itself the way the other two do.  It's the incognito choice.

In an impressive feat of aero fine-tuning Mercedes-Benz design and engineering teams have managed to make an already slippery car even more efficient with this new CLA dropping the car’s drag-coefficient from 0.23 to an amazing 0.21.

The sloping, coupe-style profile remains as a CLA signature, complete with frameless doors, flush door handles and aero wheels. 

Hybrid variants sport a conventional radiator grille decorated with a Mercedes-Benz star pattern in chrome and illuminated around its perimeter, while the EVs feature a fully illuminated LED grille display.

And in a move perilously close to branding overkill, the three-pointed star motif is carried into the headlights and tail-lights.

For Latin buffs the interior treatment is minimus extremus, the multi-screen ‘MBUX’ array in the CLA220 we drove dominating the front part of the stripped-back cabin.

From an ergonomic point-of-view, there are no physical controls for ventilation and the only non-digital audio control is on the steering wheel.

But aesthetically, the cabin is clean and simple with touches like ‘floating’ door armrests and a gently rounded front centre console adding to an overall relaxed atmosphere.

The sheetmetal is obviously very restrained given it's an Audi first, and secondly, it's just not done to go wild in this part of the market.

It's an A6 that's joined a gym, but didn't join that weird gym with men that can't run after you when you insult them (don't ask how I know this). Rolling on 21-inch wheels as standard, you can go up to massive 22s if you so choose.

The A8 created a subtle redirection of Audi's passenger car look, with the updated A4 and A6 both picking up on the horizontal bar between the rear lights and the huge grille framed by family lights with signature DRL patterns. The S8 builds on that with subtle S cues but nothing even vaguely shouty.

The interior acreage - or 'cabin', if you will - is very comfortable, but you already knew that. The multi-screen layout was first seen in the A8 and has now found its way into A7, Q8 and Q7 and is, as ever, brilliant to look at and use.

The MMI updates that have found their way into other cars are present and correct. Like the exterior, it's very restrained but not to the point of sparse minimalism, despite the lack of switches and buttons.

I really don't like the steering wheel, though, and I can't put my finger on why. It certainly isn't especially sporty-looking but I wonder if the standard flat-bottomed S wheel just looked stupid.

The materials are beautiful and everything fits together perfectly.

At just over 4.7 metres long the CLA isn’t a million miles away from full C-Class length and interior space is generous. In fact, there’s an extra 16mm in height and 12mm in width compared to the model this car replaces.

And in terms of storage there are generous bins in the doors with room for bottles and you can place them in one of the two cupholders in the centre console.

There’s the obligatory bin between the seats, a bay here for wireless device charging and a glove box, plus an extra storage bay under the flying buttress-style console.

In the back seat sitting behind the driver’s seat, set for my 183cm position and there’s plenty of footroom as well as acres of legroom and headroom. 

And part of that is the immense panoramic roof which is covered in all kinds of high-tech coatings to make sure all the light comes through but none of the heat.

Then for storage, again you’ve got bins in the doors with room for bottles as well as a pull-down armrest between the seats with three cupholders in it (one espresso-sized) and drive slot in front of them.

There are netted map pockets on the front seatbacks, individual vents which are always welcome and a couple of USB-C charging ports to keep devices charged.

Boot volume is rated at 405 litres (VDA) and the rear seatback folds 40/20/40 to liberate more storage space if required. And there’s a 101L front boot on electric models. 

There’s a hands-free tailgate on the 220 Hybrid. A 1.6- to 1.8-tonne braked trailer towing capacity is handy, but the fact there’s no physical spare tyre isn’t. Your only option in the case of a flat is an inflator and puncture sealant kit. Not good enough.

The cabin is clearly built with rear seat passengers in mind, with rear leg and headroom configured for those continent-crossing drives.

The S8 has plenty of comfort for two rear seat passengers and a few amusing options to while away the hours in traffic or on the autobahn.

That doesn't mean the front seat passengers are in purgatory, with huge but supportive seats adjustable in all conceivable directions.

Front and rear rows score a pair of cupholders and bottle holders while the boot is a handy, if not awe-inspiring, 505 litres.

For $260,000 there is a lot to get through, as there is on the less sporty A8. Start with huge 21-inch alloys, 17-speaker Bang & Olufsen stereo, panoramic sunroof, matrix LED headlights with laser lights, soft-close doors, acoustic glazing, leather trim, S front seats, extra leather over the A8, Alcantara headlining, carbon inlays, four-zone climate control, heated and cooled front seats, 'Virtual Cockpit' with S mode, and a tyre repair kit.

You also get active suspension, a sport version of the 'quattro' all-wheel drive system (with a sport differential), and a walloping great twin-turbo V8 to get you moving.

A massive touchscreen on the centre stack (familiar in Q8, A7 and Q7) hosts Audi's 'MMI plus' system, which is very good and does away with the console-mounted rotary controller. It also has wireless Apple CarPlay to go with the console-bin wireless charging pad. Android Auto is still USB. 'Audi Connect plus', now in full-featured glory, is also along for the ride.

Another technical highlight is the active noise cancelling which is meant to reduce the noise in the cabin the same way noise cancelling headphones do.

There's a clever rear seat remote control, which is a little detachable tablet to allow those who are being chauffered to faff around with various settings.

Our car had the $13,900 'Sensory Package', which adds a 1820-watt B&O 3D sound system with 23 speakers, electrically adjustable outer rear seats along with heating, cooling and massage function, and full leather.

Hybrid CLAs combine a 1.5-litre, turbo-petrol, four-cylinder internal-combustion engine (ICE) with a 48-volt electric motor integrated into a new eight-speed dual-clutch transmission with drive going to the front wheels in the CLA180 and 200 and all four in the CLA 220 4Matic.

Mercedes-Benz quotes power and torque outputs for the hybrid’s petrol engine and electric motor individually and the powertrain is able to engage both simultaneously so there are overall output figures, as well. 

The pure-electric models are powered by an in-house developed permanently excited synchronous motor driving the rear wheels through a two-speed transmission, with a second 80kW drive unit added to the CLA350’s front axle for extra performance and all-wheel-drive traction. 

Here’s a panel to explain it all.

Under that long bonnet is a 4.0-litre twin-turbo V8 pumping out 420kW and a diesel-like 800Nm of torque. 

That's a lot, even for this big bruiser. Obviously, being an Audi S-car, it has quattro all-wheel drive, which is fed by an eight-speed ZF automatic. Which is in everything now. Well, just about.

That huge torque figure is available between 2000rpm and 4500rpm while peak power arrives at 6000rpm. The 0-100km/h sprint is despatched in - gulp - 3.8 seconds.

As it's riding on the MLB platform, the mild hybrid system is a 48-volt set-up. A lithium-ion battery in the boot takes charge from the belt alternator/starter, which means the S8 can coast at higher speeds with the engine off and also cut out at 22km/h and under in traffic.

The system can also add up to 60Nm of torque in the right conditions for up to six seconds, and if it happened for me, I didn't notice it.

Hybrid CLAs are fitted with a 48-volt, 1.3kWh lithium-ion battery and at urban speeds where less than 20kW is needed, can drive using electric power alone, depending on conditions at speeds up to 100km/h. 

Official combined cycle fuel consumption is quoted at 5.4L/100km for the CLA180 and 200, which equates to a theoretical range of close to 800km, rising to 5.8L/100km for the 220 4Matic for a potential range of around 740km. 

On the roughly 150km launch drive through Melbourne's suburbs and up the Yarra Valley north-east of the city we saw an average of exactly 5.8L/100km in the CLA220.

Electric CLAs are underpinned by a specific new-gen EV platform boasting an 800-volt electric architecture and housing an 58kWh LFP battery in the 200 electric and an 85kWh NMC pack in the 350.

Maximum charge capacity is 320kW for a claimed 10-80 per cent charge time of 22 minutes. 

Claimed energy use for the CLA200 electric is 14.4kWh/100km with a range of 470km while the AWD 350 4Matic sits at 14.9kWh/100km with a range of 663km.

The 10.5L/100km official figure is, shall we say, optimistic. The launch drive was mostly highway so there's no real information to be gleaned from that, so we'll have to wait for real world fuel figures.

I'd say 12-13L/100km is achievable if you don't like having fun, in which case, the lesser A8 is probably for you.

Audi says the MHEV system saves 0.8L/100km with an early cut-out for the stop-start and the ability to coast on the highway for over half a minute at a time.

The CLA220 4Matic was the only option available for the drive program, but for the record, claimed 0-100km/h acceleration times for the hybrid models step down in roughly one second increments - 8.8 seconds for the CLA180, 8.0sec for the 200 and 7.1sec for the 220 4Matic.

Switch to pure-electric power and the CLA200 electric hits the same speed in 7.5 seconds, while the 350 4Matic electric smashes the five second barrier at a properly quick 4.9sec.

Mind you, the 350 4Matic electric weighs about 2.1 tonnes while the hybrids tip the scales at roughly 1.7 tonnes.

There’s plenty of performance in the 220 4Matic but power delivery is not always linear with the powertrain taking half a beat to pick up after you’ve applied some throttle. Which could be the interface between the combustion engine and the electric motor or the turbo on the engine.

The sports steering wheel is grippy and chunky in the hands, and while the steering itself is nice and accurate, road feel is modest. 

There are two settings for steering weight - Comfort and Sport. We tried both, and yes, you can feel where the car’s going but it’s not exactly an intimate connection between your hands and the front tyres on the tarmac.

Speaking of which, standard rubber on the CLA220 is 225/40 Bridgestone Turanza 6 on 19-inch rims and despite those relatively large wheels the car copes well with bumps and thumps and the coarse-chip surface of rural B-roads.  

Suspension consists of a newly-developed strut-based three-link set-up at the front and multi-links at the rear with all of the major components in alloy to minimise unsprung weight.

The car remains composed and balanced through corners and the sports seats in the 220 are grippy, supportive and comfortable. We spent a couple of hours straight behind the wheel without a hint of discomfort.

The CLA’s super-slippery shape manifests itself out on the highway with minimal wind noise at 100km/h and even more. The big tyres are also quiet so the cabin environment remains refined and peaceful.

Brakes on the 220 are vented discs on the front, solid rotors on the rear. And during some pretty challenging downhill twisty sections we leant on them quite heavily. Push hard and they will bite but are not overly aggressive.

The lane-keeping, driver-monitoring and other assistance features are all there, present and accounted for. But more than ticking the box, they work very well.

The media system is driven by a high-capacity unity engine which is often used in gaming and the graphics and animations are super-smooth. And the latest iteration of the Mercedes-Benz media system works nicely across the enormous screens.

All models feature a 360-degree overhead view and a reversing camera and the 11.2-metre turning circle is not small but not vast. The car is easy to manoeuvre and park.

Driving any of the cars in this segment is a rare treat, whether it's the 'entry level' diesel or this top of the heap sports sedan. My day with the S8 was filled with the usual surprise and delight that only these tech-packed cars can deliver.

Heading out of the Sydney CBD in 'Comfort' mode, the car scans the road ahead and adjusts the active suspension accordingly. You already know it has active suspension because when you pull the door handle, the car lifts by 50mm to make it a bit easier to get in.

The suspension's party trick is flat-topped speed bumps - drive at one, brake a little and sense the way the body feels like it stays exactly where it is in the air but the suspension almost completely flattens the speed hump.

It's uncanny and almost unnatural, with just the tiniest change in altitude and no noise from the suspension.

It also manages the terrible narrow lanes of CBD thoroughfares with ease, the lane keep system letting you know if you're straying.

On to the motorway and you get a feel for its crushing performance. You won't hear much, though - the stereo's noise-cancelling system shuts out almost all tyre noise and consistent wind noise is largely banished, too.

I'm going to admit I gasped when I found some corners. Active suspension bodes well for the tricky stuff, as does the all-wheel steering. Both are exceptionally clever systems for making the car feel a lot smaller in town and in car parks but they're also really good if you want some fun.

But the way the rear-wheel steer adds agility to such a big car is hilarious and clever. While you can't quite chuck it around - and really, you're not buying an A8-sized car for that kind of nonsense - brisk progress is far from intimidating.

Now, obviously, a Ford Fiesta would drive away from the S8 in the really tight stuff but it would take some time to properly shake it. The colossal torque from the V8 hurls even this two-tonne-plus limo out of the corners in a most satisfactory manner.

It's surprisingly agile for a machine more than five metres long and two metres wide. If your passengers are corner enthusiasts, you'll all be having fun in near silence. It's oddly engaging to be moving at pace in such a hushed cabin.

The S8's considerable safety equipment list includes nine airbags, ABS, stability and traction controls, forward AEB (up to 250km/h), reverse cross-traffic alert, lane departure warning, various collision mitigation and protection systems, exit warning, lane keep assist, active cruise control and on, and on, and on.

The rear seat's centre airbag is terribly clever, popping up between passengers to stop you knocking heads. Another clever trick is the way the car detects a side impact is about to happen, boosting the height of the side about to cop it to try and get the sills to take more of the impact, rather than the door.

Given the relatively niche status of the A8, let alone the S8, there is no ANCAP crash test or safety rating. One imagines given the ton of safety gear a five star rating is all but assured. Even the US IIHS gave the A8 a miss.

The CLA is covered by Mercedes-Benz Australia’s five-year/unlimited km warranty with roadside assistance included. On top of that, there’s an eight-year/160,000km warranty on the drive battery in electric models.

That general warranty is in line with Audi, BMW and other premium players, but it’s worth noting an increasing number of brands in the mainstream market are stepping up to longer seven, eight and even 10-year cover.

Hybrid and electric variants have the same 12-month, 25,000km recommended service interval with a five-year schedule for the hybrids equating to an average of $1342 per workshop visit over that period. Reduced mechanical complexity in the EV models lowers that number to $859. But neither is especially cheap in the context of class competitors.

Audi continues to fail to match Mercedes move to a five year warranty, sticking with three year/unlimited kilometre cover. BMW is still doing it too, so maybe Ingolstadt and Munich are playing chicken. 

You can get a five-year service plan for the S8, coming out at $3990 for the duration.