Mercedes-Benz S300 vs Audi S3

What's the difference?

The 2018 Mercedes-Benz S-Class remains a technological tour de force, a luxury sedan to be reckoned with - one that has safety, technology, comfort, finesse and performance all rolled into a stylish package. 

It's hard to see why you'd need anything more than the S 350 d, which is now much more attractively priced. It'd be my pick, but I'd have to get the Energizing Comfort Control package, and probably the AMG styling pack, too. And even then it would cost less than its predecessor.

The updated Audi S3 Sportback is a fun-sized dynamo with impressive outputs and athletic road manners. It’s missing a few premium features, but its compact size paired with a gutsy engine makes it a compelling option for drivers who don’t want to compromise on performance (just space).

I swear it has been facelifted, and the changes are bigger than they might appear. There is no doubt that the S-Class shape is largely unchanged, but the German company has kept the modifications minimal in the scheme of things.

That doesn’t mean those changes are unnecessary, though. The new headlights, for example, are standard on every model, and are constructed with 84 LEDs (including three for the daytime running lights), and of course they’re adaptive with automated high-beam - meaning they’ll shield other road users from the glare of the lights at night. And the lights themselves will throw a main beam up to 650 metres, according to the company. 

Other things are slightly more cosmetic, like the revised three-bar grille treatment, new front and rear bumper designs that feature broader sculpted sections to widen the stance of the car, and there are new LED tail-lights as well.

The smallest set of wheels used to consist of 18-inch rims, but now the base car rolls on 19s, while the rest of the expansive range sits on 20s. 

The inside has seen some changes, too, but the appearance of things in the cabin isn’t the focal point - its the usability of the technology that's the big change. 

Oh, but I should tell you there are now 64 ambient lighting colours to choose from, which is up from seven, and now you can also set the lighting in three different zones - so theoretically you can have blue, orange and green areas of the cockpit, if you’re gross.

The S3 Sportback may be a small car, but its S design features, like the stylised blackout grille, matrix LED headlights, and 19-inch alloys with red brake calipers, give it a distinctly athletic and fun-loving vibe. It’s compact, but definitely not diminutive and carries serious road presence. It’s hot hatch meets fun-size.

Inside, the S3 looks fabulous. Integrated ambient lighting, a sharp dashboard treatment and a driver-focused cockpit all lend it a premium feel.

The front seats look properly sporty with their integrated headrests, and the quilted Nappa leather upholstery feels great, especially with the eye-catching red contrast stitching.

As for technology, it’s as high-end as you’d expect with a 10.1-inch touchscreen multimedia display and 12.3-inch digital instrument cluster taking centre stage.

The only drawback? No sunroof. Combined with the black headliner and compact cabin, it can feel a little gloomy at times. Still, it’s a cabin you’ll enjoy spending time in.

If you’re buying a Mercedes-Benz S-Class there’s a good chance you’re more interested in the back seat than the front: you could be buying it for a business, or you could like to be driven around - and there are definitely worse places you could be.

We would suggest, though, that the best place you could be if that’s your caper is in the back of a long-wheelbase S-Class model, which has extra legroom. 

And if you happen to be in a LWB model with the 'Business Class Package', you’ll enjoy two individual rear seats rather than a three-seat bench, folding tables for your bento box or laptop, and an ‘executive seat’ on the passenger side that features a foot rest and allows you to slide the front seat forward to liberate more room. Deluxe. 

No matter if you are in one of the stretched models demarcated as such by the ‘L’ suffix or not, you will enjoy excellent seat comfort and good head- and shoulder-room. Legroom in the regular models isn’t as plentiful as you might expect: much more affordable cars like the Hyundai Sonata give the S-Class a run for its money in that regard.

There are good storage options for odds and ends, with the back seat featuring a fold-down armrest with pop-out cupholders and a storage box, as well as map pockets - and the boot space varies depending on the model, but the S 350 d has a 510-litre cargo capacity (VDA). All four doors have bottle holsters, and a bit of extra room besides. Of course there are rear-seat air-vents, and if you’re kids are lucky enough to ride around in a S-Class, the two ISOFIX/three top-tether points will be welcome.

Up front there are two cupholders between the seats, and a new wireless phone charger in the centre console (Qi compatible phones only). There are two USB ports as standard in most models, while models with the rear seat entertainment package fitted get rear USBs. 

The huge screen that runs across two-thirds of the dashboard has seen the noticeable join marker removed for this update, with the monitors being upgraded to a higher resolution and the graphics have been reworked, too. The codpiece-style controller of the Comand media interface remains, and while it still isn’t as simple as other controllers, it is reasonably easy to get used to. 

So … what about Beyonce? 

She comes in as part of the Energizing Comfort Control system, which is standard in some models and a $1400 option in those that don’t have it fitted. 

Essentially it allows you to choose between different set moods: 'Joy', 'Freshness', 'Vitality', 'Warmth', 'Comfort' and 'Training', the latter of which offers three different stretching/exercise programs that last for 10 minutes to stop fatigue. The instructions are given by voice over the sound system.

Each of the moods will adjust the temperature and ventilation (the Freshness setting offers ‘gusts’ of fresh air as if you’re at the beach!), ambient lighting, air fragrance and intensity, and the massage function for the seats. And the music bit - there are predefined songs the system can cue up to suit the mood, or it can identify songs on a hard-drive or USB that suit the programs by analysing the tempo of the tune. Amazing, right?

The new steering wheel looks a lot sportier than the one in the pre-update car, and it has finally done away with the awkward cruise control stalk in favour of steering wheel buttons for the adaptive cruise control system.

Like most hatches, the front row enjoys the most space. While it’s cosy, it never feels cramped. The seats are firm yet comfortable, thanks to their adjustability and expandable under-thigh supports. Access is fairly easy with wide door apertures, though the low seating position might earn a few grunts, especially from taller folks.

Storage up front is well sorted, with a glove box, a small centre console, a dedicated phone cradle and a couple of cup and bottle holders. It’s about what you'd expect for a car this size, but it's enough to keep things tidy.

There are plenty of charging options, with two USB-C ports in each row and a wireless charging pad up front.

The multimedia system is intuitive and easy to use. The touchscreen is responsive, and wireless Apple CarPlay connected without fuss and stayed connected all week. Wireless Android Auto is available, too.

Built-in sat nav is clear, and I love the way directions pull through to the digital instrument panel. The Sonos sound system? Pretty darn good. My son and I had more than one mini-concert on the school run.

As for the rear row, it definitely reminds you this is a small car. At 168cm, I found it on the cramped side of cosy and my husband just laughed when I asked him to try it! The wheel arch also cuts into the door aperture, making access a little awkward. Best to think of it as occasional adult seating. But given the size, that’s no surprise.

Amenities in the back are decent with a couple of map pockets, cup and bottle holders, as well as a fold-down armrest, those USB ports and rear temperature control (but curiously, no fan control). The seats are comfortable enough, but space is limited. Realistically, it’s best suited for two passengers, not three.

Boot space is quite practical. The wide opening and manageable load lip height make it easy to slide items in and out. It offers 325L of space, less than its key rivals, but expands to 1145L with the rear seats folded flat. The handy 40/20/40 split also adds versatility. Under the boot floor, you’ll find a tyre repair kit.

The A3 Sportback comes in three trim levels, with the S3 technically sitting in the middle, just below the performance-focused RS 3. It's priced from $78,800, before on-road costs, and it shares the same platform and underpinnings as the Volkswagen Golf R. Surprisingly, our test vehicle isn’t significantly more expensive than its Golf R rival which comes in at $70,990 MSRP.

That makes it a more affordable option when compared to premium rivals like the BMW M135 xDrive which starts at $83,600 MSRP and the Mercedes-AMG A35 which comes in at $89,700 MSRP.

The update sees engine outputs improve with it gaining 17kW and 20Nm of torque, resulting in a total of 245kW and 420Nm.

Feature highlights include 19-inch alloy wheels, red brake calipers, electrically-adjustable and heated front seats (with expandable under-thigh support), rear privacy glass, quilted Nappa leather upholstery and 'S Sport' suspension with damper control which lowers the ride height lowered by 15mm.

The updated technology is well-rounded and now comes with wireless Apple CarPlay and Android Auto. There's also three-zone climate control, a 10.1-inch touchscreen multimedia display, a 12.3-inch digital instrument cluster, digital radio, four USB-C ports, a wireless charging pad, built-in satellite navigation and a 15-speaker Sonos 3D sound system.

Still, despite its premium hot hatch status, this grade skips a few luxury touches. Ventilated front seats, a heated steering wheel, heated rear outboard seats and a sunroof are all missing. The BMW M135 xDrive, notably, includes all of these as standard.

Even the powered tailgate with kick-functionality is an optional extra here, adding $660 to the price. At this level that should be standard.

The big news for the majority of S-Class buyers is the new engine in the S 350d, which is a 2.9-litre in-line six-cylinder turbo-diesel with 210kW of power and 600Nm of torque. It has a nine-speed automatic and is rear-wheel drive (RWD).

That same diesel engine is wicked up in the S 400d L, with that model churning out 250kW and 700Nm, and remains rear-drive with a nine-speed auto.

The petrol model range is opened by the S 450 L with a 3.0-litre six-cylinder twin-turbo mill producing 270kW/520Nm. Again, nine-speed auto, RWD.

The S 560 and S 560L run the same 4.0-litre twin-turbo V8 petrol with 345kW of power and 700Nm of torque. Nine-speed auto, rear-drive - naturally!

The AMG-fettled S 63 has a thumping twin-turbo 4.0-litre V8 petrol engine with 450kW and 900Nm, with a nine-speed MCT multi-clutch auto and - you guessed it - RWD.

The S3 Sportback wears the quattro badge proudly, meaning it’s all-wheel drive and it pairs a tweaked seven-speed automatic transmission with a 2.0-litre turbocharged, four-cylinder petrol engine.

This update brings a bump in performance over the previous model, including the addition of a rear torque splitter. Power is now up to a gutsy 245kW and 420Nm of torque, launching the S3 from 0 - 100km/h in just 4.7 seconds. That’s proper hot hatch territory.

The diesel models are - unsurprisingly - the most frugal in the range, with the entry-level S 350 d using a claimed 5.4 litres per 100km across a range of disciplines.

The S 400 d L - which uses a higher-output version of the same diesel drivetrain as the model above - uses only a minuscule amount more: its claim is 5.5L/100km. 

The most frugal of the petrols is the S 450 L, with its six-pot petrol twin-turbo using a claimed 8.4L/100km.

Every model has stop-start - including the AMG - and the V8 petrols also feature cylinder deactivation when in 'Eco' mode.

That cylinder deactivation system helps the S 560 achieve an incredibly low claimed consumption of 8.5L/100km. So does the longer, slightly heavier S 560 L.

The higher-out Mercedes-AMG S 63 L uses 9.0L/100km, according to its claim. Amazing for the outputs of the engine.

The S3 Sportback has an official combined fuel consumption figure of 7.9L/100km and a 55-litre fuel tank, giving it a theoretical driving range of up to 696km.

Its key rivals hover around similar numbers, so it's right on the mark for the segment. After a mix of long-distance drives and my usual urban errands, my real-world figure came in at 8.0L/100km - very close to the claim, which I’m pretty happy with.

Smooth. It wasn’t even because I’d chosen the Energizing Comfort Control mood to elicit that vibe. It’s smooth - and so it should be.

Whether it’s the near-silent new six-cylinder diesel, which hauls the near two-tonne sedan along with less fuss than a medical centre receptionist dealing with a room full of coughing patients. There is no fuss. You just hand over control to the engine, and trust it will get you where you need to be.

The V8 petrol in the S 560 also has a bit of a silent killer vibe to it. There’s perhaps not as much noise as a V8 fan might want, but the mumbo is there, and in both cars the gearshifts are sublimely timed and super smooth.

Admittedly, the stiff-sided run-flat tyres on both the 19- and 20-inch wheels can exhibit a slight terseness over sharp edges, but when it comes to rolling over pockmarked surfaces or rougher country backroads, the ride offered up by the air suspension with variable dampers is superb. Put it in Sport mode and it stiffens up to the degree you’d expect, but Comfort is no doubt the best place to be.

The steering is super light but accurate, meaning it’s easier than you’d think to pilot this behemoth of a sedan through corners. The grip on offer is excellent, too, even if traction can be an issue - I had a full couple of seconds of strobe light action from the traction control light when I buried the throttle in the S 560. 

I didn’t get a chance to drive the six-cylinder petrol S 450 L, or the S 400 d L. And, I’m really sad to report, there was no opportunity to drive the AMG S 63 L, either. 

But the overall feeling of the updated range is that it remains a deluxe and delightful limousine - whether you have the good fortune of being in the driver’s seat or not.

The S3 Sportback sounds as mean as it looks, and it delivers on that promise with effortless grunt. Acceleration is immediate, with plenty of power on tap when you need it. It’s just fun all around.

The lowered sports suspension and wide tyres do bring some extra noise into the cabin, even at lower speeds. You might find yourself repeating things to rear passengers now and then, but it never feels overwhelming.

Steering and suspension are on the firmer side, so yes, you’ll feel the bumps but the payoff is sharp, responsive handling. Quick lane changes and winding coastal roads are where this car shines.

Visibility is about what you’d expect from a low-slung hot hatch. The pillars don’t obstruct the view, but sitting beside a towering SUV at the lights can make you feel a bit... compact.

Cornering is a strong suit, thanks to the car’s wide stance and AWD system. It feels confidently planted in most conditions. That said, I noticed the occasional wobble through the rear frame on rough sections in heavy rain.

Its compact size makes parking a breeze, especially with the help of multiple sensors. The reversing camera is crisp, but at this price point, the lack of a 360-degree camera view feels like a missed opportunity.

The S3 isn’t covered by its 2WD sibling's maximum five-star ANCAP safety rating but it is well-equipped with safety features all the same.

Safety equipment includes blind-spot monitoring, side exit assist, rear cross-traffic alert, lane departure alert, lane keeping aid, park assist, reversing camera, front/rear parking sensors, forward collision warning, autonomous emergency braking and adaptive cruise control with stop and go function. 

It also has six airbags but misses out on a front centre airbag. None of the driver assist systems are intrusive to daily driving, which I always like.

The rear row has ISOFIX child seat mounts and three top-tether anchor points but only two child seats will fit.

Mercedes-Benz offers a standard three-year/unlimited kilometre warranty.

Servicing is due every 12 months or 25,000km on all engines except AMG drivetrains, which require servicing every year or 20,000km. 

Mercedes-Benz has a (pricey!) capped-price servicing plan. The standard diesel and petrol models in the S-Class range cost $596 for the first service, and $1192 for the second and third visits. The costs for the sole AMG model is $736 for the first service, then the second and third visits are $1472 per.

Audi backs the S3 Sportback with a five-year/unlimited kilometre warranty, which is on par with its European rivals. A five-year pre-paid servicing plan is available for $2890 which is cheaper than pay-as-you-go and reasonable for the class.

For those looking to go the extra mile, the 'Audi Advantage' package lets you extend the warranty and capped-price servicing by an additional two years, which represents solid value overall.

Servicing intervals are every 12 months or 15,000km, whichever comes first.