People love the “smell of new car.” For most cars and SUVs, it’s a mix of plastic, stain resistant fabrics and maybe even some genuine leather. It is a complex olfactory chorus of odors that elicits an emotional response. At car companies like Nissan, there are professionals whose job is to sniff carefully and ensure that each new car has the unique new car smell.
There are so many requirements for materials used inside a car – they must last for years, be easy to clean, withstand extreme temperatures and so on – that it is very demanding to expect that they also smell good.
But these difficult requirements are the reason why automakers hire people like Tori Keerl, a materials engineer at Nissan’s technical center in Farmington Hills, Michigan. She oversees a team of odor experts who carefully analyze the odor of everything that goes into vehicles like the Nissan Pathfinder SUV and Frontier pickup. I met her on the show floor of the New York Auto Show to talk about smells and put my own nose to the test.
Keerl was originally hired as a plastic materials engineer, but in part because plastic makes up the majority of the materials in a non-luxury vehicle, she soon got the overall responsibility for the way Nissan vehicles smell inside.
“Every time we launch a vehicle, we have to test the smell of it,” she said.
As a new model develops, Keerl and her team test individual vehicle parts, such as the steering wheel, seat cushions and visors, before inserting them into the vehicle to ensure they have a pleasant – or at least harmless – odor.
“Then we put them in the vehicle,” she said. “We sit in the vehicle and we make sure that when we sit in the driver’s seat and when you sit in the back seat, you smell the good smell of new car.”
The smell in the front seat can be huge different from smells in the back seat, she said. On the front seat there is a much larger selection of materials near the nose. In addition to leather or fabric seats, there is plastic on the dashboard and whatever the center storage console is made of. There are also all the bonding materials, threads and adhesives that hold these things together. On the back seat, you are much more surrounded by only seat materials. There are seats in front of you, behind you and under you. Then there is the smell of the carpet material under the feet.
Although all the components in the car at that time had evaporated before being installed in a prototype vehicle, there are still surprises. As with cooking, some fragrances that are absolutely fine, or even very lovely, can come together alone to create a hell of a funk. Or sometimes there was an odor that was somehow missed in all the previous snuff.
Then Keerl’s team should start investigating. She and the members of her team are all “certified smells.” (There is a training and certification that involves carefully administered odor identification tests.) They begin their investigation in the same way that you would try to find a strange odor in your own car. They methodically sniff every inch of the car’s inside until they narrow where the offensive odor comes from. When they narrow the strange odor, they begin the process of revealing exactly what material or combination of materials is causing it.
Often, a surprising odor in the pre-assembled vehicle is due to a supplier changing some aspect of how a part is made. In that case, Keerl said she will work with the vendor to find out what has changed and see if the issue can be resolved.
Because a person’s sense of smell can change over time, even from day to day, the professional senses of smell are regularly recertified with blind smell tests. They are provided with unlabeled vials with different scents and asked to identify each one.
I tried it myself and it was surprisingly difficult. Smelling a smell without seeing what it’s coming from is a bit like seeing your child’s first class teacher in the supermarket checkout line. You know you’ve met this person before, but without the normal context you can not remember where or how.
I opened my first vial and smelled something vaguely pleasant and rich. It smelled … earthy. When that word came to mind, I realized I smelled dirt. It was a can full of earth. The next vial somehow smelled woody. I could not admit that I smelled pine shavings, but when Keerl told me that, I felt a little silly. Guy may be one of the world’s most recognizable smells, but without being able to see the tree in front of me, I could not quite place it.
Because attitudes toward odors vary from culture to culture, Keerl’s work focuses on cars designed for North American customers. Car buyers in Europe and Asia may not appreciate an odor that we find perfectly appealing here. They may not like the “new car smell” that Americans appreciate and prefer no smell at all.