Mercedes E220 CDI Cabrio

Large Mercedes cabriolets have always been a classy package, but this new model sets higher standards than ever. The driving experience is sublime and it looks elegant and reassuringly expensive. The small-capacity diesel engine takes little away from that combination, yet adds great fuel economy and a wallet-friendly price tag.

There’s a new way to enjoy this year’s hopefully fine summer, but you won’t have the wind in your hair in the new Mercedes E-Class cabriolet. With a clever aerodynamic device deployed above the windscreen frame,
the driver, passenger and, more particularly, rear-seat occupants should be shielded from the wind blast in the coolest conditions.

AirCap has been in gestation for more than 20 years, but top brass at Mercedes refused to give it the green light as they felt it ruined the lines of their elegant, two-door, four-seater cabriolet. The aerodynamic department kept tinkering with the concept, however, which extends out of the top of the frame and directs the air above the cabin. What swung the deal was when bosses sat in the rear – and found that they could have a conversation in relative warmth and comfort.

It works really well, but only at speeds above 50mph with the windows up. When the car detects that the rear seatbelts are fastened, it automatically raises the rear headrests and a wind deflector between to further protect the passengers.

The extra drag of AirCap cuts fuel economy by 1.7mpg over the E-Class Coupé. But this is a small price to pay for the feature, which will be standard on the cabriolet when it arrives here at the end of the month. The revised AirScarf heater outlets in the top of the front seats will be options – a pity, as they also work well and allow driving comfort in the most inclement weather.

Of course, if the rain really starts to hammer down, you can raise the vast powered fabric hood. It whirrs up or down in 20 seconds at speeds of up to 25mph. The top is double skinned and insulated to keep the noise out and heat either in or out.

Big four-seat cabriolets have formed part of Mercedes’ line-up since before World War II. The range reached its peak with the beautiful W111 series from the Sixties, but these have always been expensive and rare.

In recent times Merc’s best year in the UK was 2004, when it sold 2,392 drop-tops. Yet in 2008, that had fallen to 1,464. The firm is hoping the range’s greater fuel efficiency, together with price savings averaging 3.5 per cent, will attract more customers.

What might also appeal is that, for the first time in the UK, diesel power will be offered. Two oil-burners will join three petrol engines in the range, and buyers get a choice of five and seven-speed automatic transmissions, as well as a six-ratio manual.

The starter diesel is the 2.2-litre four-cylinder turbo. It promises 0-62mph in 8.8 seconds, a 144mph top speed and 53mpg-plus fuel returns.

On the road, this is a willing unit, and it sounds like a diesel only at idle or when pressed hard. There is never a sense that this is an entry model; more that the engine suits the 1.8-tonne cabrio perfectly. There’s enough power to overtake safely and even have some driving fun – but the economy is astounding.

While the ride and handling suffer from having the roof cut off and there’s some scuttle shake, the E-Class is still smooth. It’s agile in bends and the steering is well weighted and accurate, if short on feel. Add powerful, progressive brakes, and this big Mercedes cabrio is better than ever.

Rival: Audi A5 Cabriolet
Good-looking A5 suffers from body flex, especially when on really low-profile tyres. And while the new turbodiesel engine is terrific, it lacks the firepower of the Mercedes unit. Cheaper than the E-Class, but not as special.