Nearly every car you buy today, well at least the trunked variety, has some kind of rear spoiler. Most are just for looks, but apparently they also do have some kind of function and it isn’t necessarily related to increasing downforce.
Dr. Aonghus McNabola; a lecturer in the engineering department at Trinity College in Dublin, Ireland recently concluded in a published paper that rear spoilers on cars, set at certain angles, create a pocket of pollution at the head height of pedestrians and cyclists following in a car’s wake.
Dr. McNabola’s research also suggested that the greater the angle of attack of the spoiler, the higher the concentration of pollution at head height.
“If the spoiler is flat it can have a positive effect,” Dr. McNabola remarked during a telephone interview. “But at angles greater than zero it leads to an effect that could contribute to the overall exposure of someone cycling, walking or even driving behind the car.” He also said that the spoiler’s placement on the trunk does not matter as much as its angle.
Dr. McNabola’s findings however, were based purely on modeling, not real world testing, so it’s likely difficult to determine the true effect a car’s rear spoiler would have on concentrating exhaust pollution at head height.
[Source: New York Times]