Slip into the driver's seat and feel at home: comfy seats and handsome bodywork lure buyers into the showroom. But if a new car does not smell right, the sale may never complete. All the carmakers employ olfactory experts, co-called aroma chemists, to create complex mixtures of chemicals that, when combined, give a recognizable and attractive interior smell. It ensures potential customers feel at ease, without being able to say exactly why.
"The smell of a new car must not be penetrating and it must be appropriate for the car," said Vincenzo Luca of Germany's Tuev type approval body. A flowery fragrance could deter buyers as much as the smell associated with various kind of plastics such as polyurethane. Strips of fragrant textile can be placed under a seat or aroma dispensers installed discreetly.
The Mercedes-Benz S-Class flagship limousine comes with a perfume atomizer which can be programmed to infuse the cabin with scent. If a would-be buyer finds the smell of a new car unattractive, the salesman will have an uphill struggle convincing him or her to buy. "First impressions can actually play a key role, especially if the smell is perceived as being unpleasant," said Michael Franke from Europe's largest maker, Volkswagen Group.
An off-putting aroma is far more likely to be picked up by the buyer quickly than a subtle, pleasant scent, so manufacturers make sure that "smelly" interior materials are not used in the first place. Mercedes-Benz employs a "nose team" which is responsible for making decisions about which materials are to be used in cars - ranging from textiles, wood and rubber to the synthetics.
Back in 1992 the company developed a standardized analytical procedure which has been steadily improved down the years. The materials to be used for a new vehicle are each placed in sealed glass jars and heated to 80 degrees centigrade - this gets the effect of a vehicle after it has been roasting for a while in hot sunshine.
After letting them cool down, the olfactory experts smell the result in the jars and give marks from 1, the best, to 6, the worst. Everything that gets an average of between 1 and 3 passes the test. "The aim is to create a pleasant aroma that is as neutral as possible," said Claudia Schempp, a trained chemical-technical assistant who has been part of the olfactory team for more than 25 years.
There is no standard smell for the interior of a Mercedes car, since the material mixes vary throughout the range. "The only smell that is allowed to make a conscious impression in a Mercedes-Benz is that of leather," said Schempp. While American and European drivers find the smell of leather luxurious, Indian and Japanese drivers are not so keen on it.
Audi goes to equal lengths in order to ensure a sweetly scented experience. Staff at its olfactory department analyse around 500 components per model to gauge the aromatic impression they create. Neutrality is the aim here too. "There never will be a car which smells of nothing at all. People don't want that," said team boss Heiko Luessmann-Geiger. In aroma terms Audi does not distinguish between the entry-level A1 and the ultra-luxury A8 limousine, said spokesman Josef Schlossmacher.
Ford Germany also maintains an aromatic department, but not a dedicated design studio for scents. The smell of a new car used to be associated with a "pungent plasticky aroma" which was something to be endured until it wore off, said Luca. The emissions from some plastic compounds used to be so intense that the windows fogged over. That seldom happens today.
"Until the beginning of the 1990s, little attention was paid to the aroma of a new car interior," said VW spokesman Michael Franke. "In some cases people actually liked what they smelled." Some new cars are still "stinkers" in olfactory terms, especially when low-grade plastics are used. Buyers who are put off by this should air the car extensively, since fumes from some materials can make the driver drowsy or cause headaches.
Motorists keen to neutralize the bad smells in a well-used car can buy air fresheners and scent dispensers specially sold at auto parts shops and garages. These can often dangle from the rear-view mirror or adorn dashboard ventilation outlets.