Six things you need to know: new Mercedes-Benz S-Class

You’ll have noticed by now that, even wearing all that psychedelic camouflage, the new S-Class – which we’ll see minus camo for the first time in April – looks pretty much exactly like the old one. That’s because this isn’t an all-new car, but a facelift, and a fairly mild one at that. Most of Mercedes’ efforts have instead been focussed on its driver assistance systems… 

Most of it, anyway, and only if you’ve specified the right packages and options. Because the existing S-Class has been around for a few years now, its systems aren’t as advanced as those fitted to the new E-Class. And that simply won’t do. The S-Class is supposed to be the technological pinnacle of Merc’s range – the car you look at to see what your C-Class will have in five or ten years’ time. The E uses what Mercedes refers to internally as “generation four” of its assistance suite, while the old S uses “generation three”. The new S is not such a step change – Mercedes call this “generation four point five”, meaning rather than a mass of new hard- and software, it has finessed versions of systems fitted to the E-Class plus one or two extras besides. We went to Germany to try some of them out. 

I’m in an E-Class with a man called Frank Mohn, a Mercedes engineer I was later told basically invented ESP. He’s about to show me the Active Braking system, which is set to be fitted to the new S. 

We’re sat at the end of a long strip of tarmac painted to look like a three-lane carriageway. Some distance ahead are cars in the out- and inside lanes, and an inflatable one in the middle. That’s the one we’re aimed at. Frank asks me what I think will happen. “It will stop the car” I reply. “You hope so,” he says. 

As Frank accelerates towards the inflatable car, and through the beep warning him there’s an obstacle in his way, I consider the possibility he’s actually gearing up to demonstrate how much more comfortable Mercedes has made its next generation of airbags. Thankfully I’m proven wrong, as the E-Class brakes, quite gently at first, then much harder. We stop a couple of feet from the inflatable’s back bumper. “Have a look at my legs,” says Frank. I peer over the centre console. His foot is still on the accelerator. “This is possible up to 62mph. And we can detect up to 80mph,” he says. 

But at these kind of speeds, this is only possible when all lanes of traffic are blocked – where there is no alternative path for the car to take. “We do not do changes with our steering in emergency scenarios,” Frank explains. “What is in front of this car? Can you come back? What will happen if you change to the right side, and there is a car parking or a mother and a baby? How can it decide if you can use this lane? This is the reason you do not have anything that steers around a problem like this.”

We set off again. An inflatable car crosses in front of us, as though it’s run straight through a crossroads without looking. The E-Class sees it, decides it will still be in the way when we arrive and, once again, slams on its own middle pedal. As if I’m not already convinced, we try again. This time the E-Class decides it doesn’t need to do anything to avoid the (I think inevitable) crash. Sure enough, the inflatable car passes in front of us without the E so much as tapping the brakes or flashing up a warning on its dashboard. We miss it by inches. This makes Frank very happy. “Masterpiece of intelligence! It calculates that we can come through without any crash, so we mustn’t irritate the driver and do a brake process. You like it?” 

I leave Frank and join another active safety engineer, Elisabeth Hentschel, in yet another E-Class (pictured), which like the new S-Class has something called Remote Parking Assist. I hit the parking button on the centre console as we roll past a couple of SUVs at 10mph or so. A ding tells me the E has seen a space. Stick it in park, confirm on the centre-screen, and it begins slotting itself into said space – managing the accelerator and brakes and switching between D and R as required without any input from the driver. If you’re doing end-on rather than parallel, you get to choose whether you go in front- or backwards. If required, it will indicate in the necessary direction and fold its own mirrors. And It’ll get itself out of a space too, though you have to watch for traffic (unless it's reversing itself out of an end-on space, where it'll jam on the brakes for you if there's a passing car). 

The really impressive bit is that none of this requires you to actually be in the car. Confirm the manoeuvre, stick the key in your pocket, hop out then open the app on your phone and issue the command. As long as you keep swiping a concentric circle on the screen, the car will carry on, changing gears, steering and braking/accelerating as needed. If you get back to the car and someone’s parked so close you can’t open the door, you can extract it using “Explore Mode”, which lets the car travel 15m forwards or backwards, and steer around obstacles in its path. Very cool and very clever, but its usefulness is debatable. 

Something the E-Class cannot do. For this one, we hop in a disguised S-Class like the one pictured with engineer Volker Klink. He’s going to demonstrate something Mercedes calls “Active Distance Assist Distronic” – in layman’s terms, an even cleverer version of its adaptive cruise control. In the E-Class the ultimate version of this system maintains a gap to the car ahead (varies by speed and setting, all the way down to a stop) and keeps the car in its lane. It’ll change lanes for you, too (but not in the UK. Laws), and adjust the set-speed to whatever the speed limit is because it recognises road signs. 

The S-Class does all of this too, only Mercedes has recruited GPS for another bit of functionality. The system can now predictively slow the car for upcoming obstacles, like roundabouts, junctions or slip roads. Even toll booths. Or just plain old corners. 

“The system looks at the profile of the road,” Volker says. “So if you have a curvy mountain road with a 100kp/h limit, but no one would drive it that way, the car would slow to whatever is comfortable for that kind of road. It will show you whatever the situation is in the dashboard.” Clever stuff. 

If you’re approaching a roundabout, say, the system will slow the car from its set speed as you approach. If there’s something coming, you have to hit the brakes as you would normally – it won’t stop for you – but if there isn’t, you needn’t touch anything. Simply steer around the roundabout, and the S accelerates back up to speed once you’ve taken your exit. If you’ve got the GPS set it knows what exit you’re taking, and will plan accordingly. If not it does it on the indicator, whether you’re indicating left, right or not at all. This is all communicated to the driver via symbols that flash up in the instrument cluster – different ones for each reason the car might slow. 

The way it brakes and accelerates varies too. More harshly in Sport mode, softer and less aggressively if you leave it in Comfort. Shove it in Sport + and it’s last of the late brakers. And because the GPS has been hooked up to the speed limit assist thing, the S knows what speed limits are coming and rather than retroactively braking once you pass the sign, will slow beforehand so you’re doing, say, 30mph as you enter a village. 

Oh, but it can’t detect whether a traffic light is red or green, though Mercedes, “like everyone else”, is working on that. 

For all its processing power, the new S-Class only offers level two autonomy – where the automated system does most of the driving, but the human behind the wheel still has to be able to take control at any point. He can’t read a book. With level three he can, but only in specific situations – like driving on the motorway. Mercedes senior manager for function and software driver assistance systems (phew) Taner Kandemir expects to “achieve this within the next generations,”, legislation permitting. 

“We have a long tradition in driving assistance systems,” he says. “We started in 2000 with the S-Class and a Distronic system, and from the very beginning it was very clear that we need to have a very reliable system for the customer.

“You see it could also be possible to bring it further on, but the question is still whether it’s understandable for the driver, what he can expect and what he can’t expect. We still have this hands-on detection. Maybe you could say it’s boring to get this beep, but it’s necessary because we have a level two system. All the other guys also have level two systems. Getting to the next level and achieving it so it is understood and reliable we will do next.”

Taner also tells us making autonomous cars drive like humans is “always our aim, and it will be the same in level three”.