car manufacturer quality control

a nose for detail ?


Despite being ferociously quick, ruggedly handsome and shot through with testosterone, the now defunct TVRs of the eighties had a problem. Their fibreglass bodies smelt like a sun ripened cat litter tray. The rank odour permeated the cabin and TVR owners could be witnessed surreptitiously sniffing at each other in a grimly primeval bonding exercise. Thankfully, as consumers have become more demanding, quirky characteristics such as these are now designed out, and quirky testing procedures have sprung up to ensure that nothing about a car's design is left to chance.

No manufacturer takes smell more seriously than Audi. An entire 'Nose Team' is employed in Ingolstadt with the sole responsibility of ensuring the requisite Audi smell. And what should an Audi interior smell of? Depending on trim option, either nothing or leather. Schmidt's initial brief was to investigate why the inside of windscreens fogged up over time with a misty film. This was eventually attributed to the plastics used for the dashboards leaching tiny chemical particles - particles which had a distinctive and not entirely pleasant smell. Nowadays, every material used in the car passes under the twitching nostrils of the Nose Team, from the leather used to trim the interior to the dyes used to tint the trim and even the exterior body panels.

Extreme measures are taken to guarantee aromatic neutrality. The cars are driven to Algeria to be smelt in the incinerating Sahara sun, ensuring that temperature changes will not provoke an unwelcome olfactory reaction. Creating the perception of quality is the driving force behind the Nose Team, and until Audi find a more sensitive instrument than the human nose, with its ability to plug directly into the brain's memory centres, the staff at Ingolstadt will still be required to sniff, bake and sniff again every single material the customer comes into contact with.

Sounds, as well as smells, are a key aspect of modern car design. The Ford Focus' massive sales have owed much to its perceived depth of quality, a perception which Ford's Acoustic Centre at Merkenich, near Cologne, had sought to reinforce. "Motoring enthusiasts have always liked a good, solid 'clunk' when the door shuts," says Lothar Hoppen, the supervisor of Noise, Vibration and Harshness at Merkenich. "But in the past, if that sound was consciously developed at all, it would have been very unscientific. Maybe just three or four people standing there one day and agreeing it seemed okay to them." Ford recognised the showroom appeal of a substantial sounding 'door slam' with the Mondeo, and applied these theories to the Focus, creating an acoustically pleasing thud which was once the preserve of much larger and more prestigious vehicles.

Another priority for the Acoustic Centre was the ticking noise generated by the Focus' direction indicators. This noise originated from a mechanical relay used to operate the light flasher and has become familiar to several generations of motorists. Whilst relays have long been replaced by electronic systems, Ford realised that drivers wanted to hear the reassuring ticking sound, and anything else would serve as a dissatisfying characteristic. In order to generate the most pleasing sound, Ford set up target market focus group to undergo Psycho-Acoustic word association tests and to be subjected to a barrage of indicator sounds to establish a favourite. In addition to the indicators and door slam, the acoustic tuning for the Ford Focus included the sounds of central locking and door release, the 'snap back' of the door handle, the electric windows, the release and closure of the tailgate, the windscreen wiper motors and the push and turn dashboard switches.

If the images of a workshop of engineers gravely sniffing parcel shelves or a windscreen wiper motor being miked up for a recording raise an eyebrow, then a trip to Nissan's Sunderland plant would be a true revelation. In the realm of quixotic testing procedures, Nissan are the undisputed champions. Whilst Mercedes merely employ Paint Doctors to run their gloved hands over their bodywork to ensure the paint is blemish-free, Nissan have a whole array of projectiles which are fired at the paint to test its durability. In order to test stone chipping resistance, diamonds are fired at 170km/h onto painted body panels using a compressed air blowpipe. Nine shots are fired at each panel before the test is repeated at -20 degrees centigrade, as paint becomes more brittle at low temperatures.

The paint is then subjected to a sound spattering of Nissan's patented artificial bird dropping mix. This sticky goo has the same corrosive properties as the real thing, but offers better consistency between samples. This concoction is then baked for an hour at 50 degrees centigrade before being washed off and the paint inspected for blemishes. After this, the test is repeated with Nissan's 'secret formula' artificial squashed bug compound. Aside from these tests, Nissan also inserts nappies into the engine bay to test for water ingress, coats the underside of the car in Bacofoil to ascertain where stone chips are most likely to occur, and subjects the cars to a blinding ultra violet light that simulates ten years of the world's most intense sunlight exposure. Perhaps the most unusual test involves the use of a denim jeans clad artificial bottom, modelled on an 11 stone person which slides onto a car seat, rubs back and forth three times and then slides off. This test is repeated 15,000 times without a break for three days, equivalent to 32 years of commuting, and only seats which look as good as new make it into production. Will Nissan ever make the logical step and employ a team to smell the denim-clad posteriors of Primera-driving cabbies? Surely a breakthrough not to be sniffed at.