Euro VII proposals released last year further restrict those levels, as well as CO2, and bring into scope emissions from tyres and brakes.
This is a positive move. Promoting environmental sustainability is part of the mission statement of the SOE. The transport industry should be thinking about where tyre and brake particles go as they wear down: on the truck, the road, in the verges and the gullies that drain the roads, and onward into our rivers, lakes and seas.
Even if not for environmental reasons, professional operators are already doing this for the economy. They are trying to keep the particles on the tyres in the first place, to minimise cost by maximising the life of expensive consumable items. Systems like walk-around checks make sure tyres aren’t flat, and regular tyre checks keep on top of wear in a systematic way. Drivers are trained to avoid harsh braking and acceleration. Part of this involves keeping good records of when tyres and pads are changed, whether or not such information is being reviewed. That’s the first step.
The second step is to set expectations: what does ‘good’ look like, when it comes to wear? Of course every duty cycle will be different. But operators don’t have to bother grouping their vehicles or defining duties. Provided that their fleet is set up so that each vehicle always carries out the same job over its working life, fleet engineers can track the performance of consumables fitted to that, on a vehicle-by-vehicle basis. If a tyre lasted 100,000 miles on that truck, an identical replacement should last the same.
The third step is to try out improvements through trials using methodologies such as the A/B testing.
Wear/emission would seem to complement the three factors currently measured in the EU tyre rating (wet grip, noise, fuel efficiency). Therefore, this new attention on tyre emissions might alter the balance of these in future tyres. Even though revised labels were only launched in 2020, maybe they should be revised again to include this as a fourth dimension.