Stuttgart - Car makers are constantly modifying their vehicles to please the buyer and olfactory senses play no small part when it comes to the choice of materials. In the past, research has concentrated on minimising unpleasant smells from paint, leathers and adhesives. Audi for instance has hired an entire team of "sniffers" from the chemicals and perfume industry who "sniff" every car part before it is approved for production.
But increasingly, car makers are bringing smells into the car as part of the production process with Citroen, Peugeot and Fiat integrating a pleasant aroma into the car ventilation system.
Such a process currently faces two major obstacles, according to Frank Leopold, an Opel researcher.
"The buyer has to choose an aroma that might be unpleasant for other passengers and many of the aromas still have an unnatural and synthetic smell," he says.
"If we can find the right composition of various aromas, then these can be distributed individually in the vehicle. A tired driver can be activated, stressed children on the rear seats can be calmed and a fresh breeze may be activated during a hot drive to a holiday destination," according to Leopold who wants to integrate an "aroma organ" into the car ventilation system.
Olfactory senses can play a key part when choosing a vehicle. A premium vehicle can be designed with a cabin smell similar to an exclusive club room or Grand Hotel. A convertible might appeal with the smell of a fresh summer meadow.
But, the technology is not yet ready for production and Opel will for the time being offer its vehicle with a neutral smell, Leopold says.
At Mercedes-Benz, the head of customer research, Goetz Renner, says the emphasis is on driving pleasure. In the past manufacturers concentrated on keeping disturbing elements out of the car.
"Now we must look more at stimulating the senses," Renner says.
When motorists spend most of their time driving through huge cities and in traffic jams, other senses need to be activated, according to the Mercedes researcher.
"In the coming years we need to look at innovative new systems that improve the air quality in the car including aromas," according to Renner.
But already there are many motorists who have simply had enough of being bombarded with all sorts of smells during their day. The European division of the Mazda design team headed by Peter Birdwhistle is taking a different approach with its small car study Kiyora at the Paris Motor Show.
The Kiyora has an in-built air freshener system, cleaning theair outside with a filter before it enters the cabin. The system is a big advancement over the filter mats found in most current air conditioning systems.
"We want to emphasize that for many people today the car has become a place of seclusion where one can relax and recuperate," according to Birdwhistle. For motorists who do not want to wait until there is a production-ready car with a smell that they like,there are many air freshening sprays and other items available on the market. The German producer of such aromas, Boehm, says the vanilla aroma is the most popular with 27 per cent of German customers. Second place at 13 per cent is the "sport refresher" with the aroma "New Car" bought by 10 per cent of customers.
An air freshener might not be enough if you want to remove unpleasant odours left by a previous owner such as cigarettes and the smell of pets.
"In such a case the only method is an ozone treatment," says Hans-Georg Marmit from the technical testing organisation (KueS).
"The car is completely sealed and filled with ozone for between 12 and 24 hours, neutralising all the smells that come from bacteria nestled in the most unlikely of places", says Marmit. However, it is not cheap and between 70 and 300 euros (100 and 425 dollars) depending on the extent of the treatment.
