UNECE completes work on new car tire-abrasion regulation

Geneva, Switzerland – Work on a new UN regulation covering tire abrasion for passenger car tires (C1) has been completed, with first new type approvals required from 30 June 2028, according to the task force on tire abrasion (TF TA) within the United Nations Economic Commission for Europe (UNECE).

The regulation covers C1 tires for passenger cars, C2 tires for light commercial vehicles and C3 tires for heavy commercial vehicles.

In a progress report which was presented to the 84th session of the working party on noise and tires (GRBP) 2-4 Sept, the TF TA outlined the conclusion of its C1 work and the next steps for C2 and C3 tires.

“Agreement was reached on the endorsement of a package supporting a new UN Regulation on tire abrasion for C1 tires, along with the necessary consolidated amendments to UN Regulation 117,” the report said, following an extraordinary GRBP session in March 2026.

The new UN Regulation 186, which specifically focuses on automotive microplastics emissions, will have a “two-stage implementation approach.”

Under stage 1, “new tire type approvals [are] required from 30 June 2028”, while compliance will become mandatory for all tire type approvals from 30 June 2030.

The regulation also permits tires manufactured before June 2030 to be fitted to vehicles in use until 30 June 2032.

Stage 2 will introduce “tighter abrasion limits and adjustments across tire categories”.

New type approvals under the second stage will be required from 30 June 2033, with the requirements becoming mandatory for all tire type approvals from 30 June 2035.

The report also stated that “extended acceptance of stage 1 approvals” will be allowed through 30 June 2035.

The C1 programme followed an extensive market assessment and test campaign, according to the task force.

The market assessment, it said, was completed in March 2025, as was a correlation and validation study of the two test methods: on-road testing (convoy method); laboratory testing (drum method).

Foundational test conditions and methods for C1 tires were adopted as a new supplement to UN Regulation 117.04, with the amendments adopted by the World Forum for Harmonization of Vehicle Regulations (WP.29) in June 2024.

The task force's remit includes developing procedures for measuring tire abrasion, defining acceptable test-method uncertainty, assessing the relative mileage potential of tires and establishing abrasion limits in order to limit the emission of microplastics to the environment.

C2 work moves to 2027

With the C1 regulation completed, the TF TA said it was moving into work on C2 tires.

According to the progress report, initial testing using both summer and winter standard reference test tires has shown that C2 tires exhibit “temperature sensitivity that may differ from that of C1 tires”.

The 2026 test campaign will focus on confirming the reference tire strategy, assessing temperature sensitivity and evaluating the impact of tire pressure.

The task force had originally planned to submit a formal working document on the C2 test method to the September 2026 GRBP session.

However, it said this was “no longer viable” because of the complexity of the ongoing test campaign and the need for low-temperature data expected in the fourth quarter of 2026.

An informal document presenting the C2 method was instead be submitted, while the formal working document has been postponed to GRBP in February 2027.

The task force is then targeting September 2027 for a working document proposing C2 tire abrasion limits.

C3 work to begin with October workshop

The C3 programme presents a greater technical challenge, according to the task force.

It said there was a “severe complexity and distinct lack of synergies between C1/C2 and C3 tire segments”.

As a result, the TF TA will first hold a two-day hybrid brainstorming session in Brussels in October 2026.

The aim is to develop “out-of-the-box, simplified test methods and tire segmentation approaches” before physical testing begins.

A working document proposing C3 abrasion method(s) is targeted for February 2027, “subject to review based on outcomes of brainstorming”.

A proposal for C3 abrasion limits is targeted for September 2029.

Task force set to become working group

The TF TA is also proposing to move from a task force to an Informal Working Group on Tire Abrasion (IWG TA) as the work expands from C1 to C2 and C3 tires.

The report cited the “growing complexity and long-term nature” of the group's mandate and the need to maintain “high visibility and appropriate standing” for the tire-abrasion regulatory framework within GRBP's priorities.