On this episode of the Fueling the Future podcast, I spoke with Nick Molden, founder and CEO of Emissions Analytics, about non-exhaust emissions in vehicles. Following is an excerpt from our discussion, which you can download or listen to at the link below or listen to in ITunes. See also the recent post Tires Not Tailpipe about this issue on the blog.
“Non-exhaust emissions generally encompass three things, which is material lost from tires during operations, from brakes, and also from the road surface itself so, obviously, not only do the tires wear, but the road surface wears, as well. These three sources create particle emissions. We decided to focus on tires first of all because we believe that is the single largest of the three as a source, but also that it’s growing as a problem, and there’s strong evidence that the heavier the vehicle, the more the tire wear emissions are, everything else being equal, whereas brake wear, we have more regenerative braking may well decline, so tires was our priority out of those three.
It’s very easy just to take what we’re regulating today and just make that progressively tighter and tighter over time, and there’s an arms race between regions to just regulate harder. One of my concerns is that, actually, that’s not the efficient way of doing it, particularly as if you put all the effort into that and neglect something else which is not regulated, which is actually more important. I think we’re getting to that stage now with the tailpipe.
With modern vehicles, particularly modern diesel vehicles, there’s now so little pollutants coming out of the tailpipe, except for CO2. They’re getting down into the regions of being very hard to measure, and that includes particle emissions. The regulated level in Europe for particles at the tailpipe is 4.5 milligrams per kilometer, but reality from our data, it’s probably a tenth of that and, in certain circumstances, 100th of that, so we’re now talking down to extremely low mass of particles coming out of the tailpipe, yet that is the thing which is regulated, and tires are not regulated.”