Is Mercedes-Benz E-Class the cleverest car of the century?

This time last week I was driving at high speed on a motorway near Lisbon without needing to steer to keep in the lane. If I wanted to overtake or pull in, the car obligingly steered when I indicated. If this was dangerous it would warn me '“ and take avoiding action if I had gone too far. My co-driver even took his hands off the wheel to put a number into his phone. He could just as easily have eaten a snack, had a drink, lit a cigar.

Mercedes-Benzs new model is armed with a dizzying array of intelligent drive features

If he lost concentration and drifted it would pull the car back into line. Fall asleep or became ill at the wheel, it would bring the car to a safe halt. It will help drivers to obey speed limits. It will communicate with others, passing information about delays or accidents. It will warn if you are driving through a no-entry sign or going the wrong way up a motorway or on a roundabout.

It will brake if another vehicle crosses, in front or when reversing. It will stop for pedestrians or cyclists crossing too close to the car – or help you steer round them. It will help avoid a collision if you or an oncoming vehicle stray over the centre line by turning away, using the appropriate brake. The steering wheel does not move. If a side bump does happen, the front occupants are pushed towards the centre of the car and away from the doors. If a crash is anticipated, your ears are prepared for the noise by a brief aural signal which interferes with the shock of the collision noise. This “stapedius” reflex reduces the risk of damage to the ear drums.

The car? The new E-Class saloon from Mercedes-Benz, the cleverest car so far this century.

An option are headlights with 84 individual LED “bulbs” at each side. These adapt to the road and distance of vision and will darken in clusters to avoid dazzling oncoming vehicles or causing too much flare from road signs. At the back, the brake lights dim to reduce the glare for drivers or bikers behind.

There are disclaimers and warnings. For example, Mercedes is not suggesting that the driver actually takes hands off the steering wheel when barrelling down the road. It’s seen as the next step towards a truly self-driving car and, at present, a way or reducing the driver’s physical input, reducing the strain of long journeys, and taking care of unexpected hazards outside the car or driver error. It will ease your effort in stop-start traffic or negotiating road works where the lane markings have become unclear.

Having experienced it on the open road and in special closed road displays at the Estoril race circuit, it’s clear that the semi hands-off steering at speed goes against your instincts and requires immense trust in the car’s computerised brains. The “follow me” system works within specific speed bands depending on whether there are lane markings (achieving higher speeds) or not. Its cornering ability is also affected by speed and the radius of the curve but it will manage a typical motorway bend at 75mph and follow other vehicles in marked lanes at speeds as high as 130mph – the normal maximum legal limit in dry weather in mainland Europe. On roads without clear markings it can follow at 80mph.

The Drive Pilot self-steering and various extra-cost packs as part of the Intelligent Drive Next Level. The standard E-Class has active braking, crosswind deflection, loss of attention intervention, the pre-safe crash mitigation system and ear protection, Garmin Navigation.

Prices start at £35,935 for the E220d SE. The AMG Line is £38,430. The other model at showroom launch in May is the E350d, costing £44,930 for the SE and £47,425 for the AMG Line. All have a nine- speed automatic gearbox. An estate version is on the way followed by a coupé and convertible next year.

As you would expect, the rest of the E-Class has been thoroughly revised. It is slightly longer, is 100kg lighter, cleaner and more aerodynamic. The standard suspension for Britain is a lowered comfort setting, with adaptable air suspension (as tested) standard on the E350d, or a £1,495 option on the E220d. The Drive Pilot pack is £1,695. A wide screen information and navigation system with searching and inter-car connection is standard on the E350d, or £1,495 extra on the E220d. A continuous variable screen display is an additional £495. You’ll want it when you see it.

Verdict: Masterclass in refinement, even without the extras.