EVU XXIV 2015 – 25 EU Tyre Label Regulation No. 1235/2011, and its Influence on Road Traffic Safety due to Tyre Wet Grip Specification


EU Tyre Label Regulation No. 1235/2011,
and its Influence on Road Traffic Safety
due to Tyre Wet Grip Specification
Sigmar Micke, László Palkovics
Hermann Steffan, Egon-Christian von Glasner

Abstract

This paper deals with braking of Tyres for Passenger Cars, Light Trucks and Heavy
Trucks and Buses in wet road conditions. It analyses past and current legislation issued
by the EU in Brussels and UN ECE in Geneva, whereby the EU covers European
Regulations and UN ECE the global Regulations, except for Europe. EG Reg. 1235/2011,
29. Nov 2011, application date 30 May 2012, the Tyre Label legislation, has been issued
with a serious mistake in Wet Grip Class F for all Tyres C1, C2 and C3. That Regulation
specifies in Wet Grip Class F: G≤ 1.09 for C1 Tyres, G≤ 0.94 for C2 Tyres and G≤ 0.64
for C3 Tyres, which legislates for all mentioned tyres a lower limit of 0 (Zero) Tyre-to-Road
Adhesion, in the extreme. It is demonstrated, that this mistake in EG Regulation
1235/2011, 29. Nov 2011, cannot logically be explained as a “typing error” by the
responsible EU Institution, since this would not make mathematically any sense at all in
this context.
It is shown, that this very “mistake” was in fact already defined and legislated in the
predecessor of above Regulation for C1 Tyres, which was (EC) Regulation
No. 1222/2009, 25 Nov 2009, application date 1 Nov 2012. There, an identical definition
for the minimum Wet Grip Index G≤ 1.09 in Wet Grip Class F for C1 Tyres is listed, with a
legislated lower limit of 0 (zero) Tyre-to-Road Adhesion. This went apparently unnoticed
by the public, but resulted legally, from the time of application, in potentially unsafe
Passenger Cars with such C1 Tyres of Wet Grip Class F on Europe’s road system in wet
condition.
This paper demonstrates furthermore, that the predecessor of above (EC) No. 1222/2009,
25 Nov 2009, which was European Regulation (EC) No. 661/2009, 13. July 2009, had
included a correctly defined minimum value for C1 Tyres with (G)≥1.1. Application date
was 1 Nov 2011. This law, with a safe definition of G, was replaced by above listed flawed
Regulation 1222/2009 on 1 Nov 2012.
The paper analyses further the calculation of the Wet Grip Indices G(T) and G for all
Tyres. Vehicle test results are included, which demonstrate the effect of the currently valid
EU Regulations on wet roads with Tyres of various Wet Grip Classes. The paper
concludes with some defined demands on how to improve the safety with all Tyres C1, C2
and C3 on Europe’s roads. EU Wet Grip Classes D, E, F and G in the Tyre Label should
be eliminated, and the current Wet Grip Class C should become the minimum for C1, C2
and C3 Tyres.

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AutoreSigmar Micke, László Palkovics Hermann Steffan, Egon-Christian von Glasner
Pubblicato il
Tipologia