The Tyre Label is a mark for motor vehicle tyres. Manufacturers of tyres for cars, light and heavy trucks must specify fuel consumption, wet grip and noise classification of the product by means of a sticker or a label starting in November 2012.
This information must also be included in the technical promotional materials. The tyre label will use a classification from the best (green category "A") to the worst performance (red category "G” for Car and “F” for truck).
This initiative results from a proposal by the EU Commission in 2008 and it is part of the Energy Efficiency Action Plan, designed to improve the energy performance of products, buildings and services to reduce energy consumption by 20% until 2020.
(Source: European Commission)
Pirelli, as well the entire tyre industry, welcomes the introduction of the tyre label as a good tool to help the end-users in collecting some essential information when choosing new tyres. But the tyre label cannot substitute the wide range of informations offered by the tests performed by specialised magazines. Trustworthy, independent and reliable evaluations of tyre’s performances. Pirelli would like to remind to all end-users that the overall value of the tyre cannot be judged only by the rolling resistance, the wet braking and the external noise values; there are several additional elements (handling (wet and dry), aquaplaning, high speed behaviour, dry braking, wear, snow performance for winter tyres, ...) that have to be considered in order to choose the best product fitting your needs.
The EU Tyre Labelling Regulation 1222/2009 will provide standardised informations on three tyre performance attribute:
The Regulation requires that all the tyres produced after June 2012 and on sale in the EU after November 2012 will carry a sticker or have a label in their close proximity to be shown to the end user before purchasing(*).
The label is intended to give end users some essential information to help them when choosing new tyres.
(*) This information needs to be provided concerning passenger car tyres, light truck tyres and heavy duty vehicle tyres.
Rolling Restistance is a force acting opposite to the travel direction when the tyre is rolling.
Considering that tyres contribute up to 20% of the overall fuel consumption for a car and up to 35% for a truck, it is important to reach low Rolling Resistance values.
Let’s understand how it works: due to the vehicle load, the tyre is deformed in the contact area with the road surface dissipating energy in form of heat. The higher deformations, the higher the rolling resistance and consequently more fuel consumption and CO2 emissions.
In the EU tyre Regulation label, rolling resistance is expressed in grades, ranging from A (best grading) to F for industrial vehicles and G for cars (worst grading).
The difference between each grade means a reduction or increase in fuel consumption of between 2.5% - 4.5% for a car and 5%-8% for a Truck. For a car that could be also roughly expressed in terms of 0.1l/100km.
Wet grip is one of the most important safety characteristic of a tyre. Excellent grip on wet means shorter braking distances when driving in rainy weather.
There are other important parameters which are relevant for safety but wet grip was chosen as the most representative situation in order to compare different tyres.
For a car the difference between each grade means an increase or decrease in stopping distance of roughly 3 and 6 meters when braking from 80km/h.
Traffic noise is a relevant environmental issue determined by several factors such as:
The value indicated in the label is not the internal that the driver will perceive while driving, but the external one, that is contributing to acoustic pollution.
It is expressed in decibel (dB) and split in 3 cathegories:
1 black sound wave = 3dB less than the future tighter European limit. 2 black sound waves = already compliant with the future European limit. 3 black sound waves = compliant with the current European limit.
The more black bars shown on the label, the louder the tyre.
The rules apply only to passenger car tyres (C1), light truck tyres (C2) and heavy duty vehicle tyres (C3).
The following categories are excluded from the scope:
•Professional Off Road tyres
•Studded tyres (studdable tyres if supplied without studs are covered)
•Temporary –use spare tyres
•Tyres designed to be fitted on vehicles registered for the first time before 1 October 1990
•Tyres whose speed rating is less than 80 Km/h
•Tyres whose nominal rim diameter does not exceed 254 mm or is 635 mm or more
RR is a force acting opposite to the travel direction if a tyre is rolling.
Due to the vehicle load, the tyre is deformed in the contact area with the road surface.
This deformation induces internal losses, same as a rubber ball falling down that does not rebound as high as it was launched.
Tyre RR can be expressed as a Force (Newton) or as a Coefficient (RRC).
The rolling resistance coefficient is defined as RR force (N) divided by the tyre load. The advantage of the coefficient is that it allows easier comparison of tyres designed to be fitted on different cars.
The vehicle engine has to provide a force to compensate RR.
This consumes some fuel and so contributes to the vehicle fuel consumption.
As a rule of thumb, reducing RR by 6% decreases fuel consumption by 1% for passenger cars.
Many other factors contribute to vehicle fuel consumption:
Aerodynamics, vehicle weight, type of engine, auxiliary systems like air-condition, slope of the road, personal driving style, tyre pressure level, accelerations or general traffic conditions.
There are many different tyre characteristics that affect tyre RR. Adjusting the RR can be done by modifying certain of these parameters, but some of them can also have a negative impact on wet grip.
The tyre development engineer must use the right tools in the right amount to achieve the optimum balance for RR and wet grip.
If tyre RR limits are lowered too far, the required tradeoffs could adversely affect the wet grip performance.
Wet grip refers to the safety performance of tyres:
it reflects the capacity of a tyre to brake on a wet road.
There are other parameters which are relevant for safety (e.g. road holding ability, directional control, deceleration ability on wet and dry surfaces at higher speed and aquaplaning behaviour) but wet grip was chosen as the most representative situation of reduced adherence in Europe.
A limit is the minimum acceptable performance level for a tyre to be authorized on the European market;
A grading will give the performance level under defined testing conditions of the tyre on its rolling resistance, its braking on wet surface and its external rolling noise.
It is the responsibility of the national market surveillance authorities to assess the conformity of the declared grading values.
The procedures for verification are detailed under Annex IV of the regulation
POR tyres are specially designed to reach exceptional adherence performances in poor conditions and in all terrain, which does not allow them to fulfil regulatory thresholds and significant grading levels.
There are plans to introduce labelling requirements to retreads; however this will be decided after an impact assessment is performed by the Commission. The Commission shall present the result of this assessment by no later than March 2016.
The European Commission shall start work to develop a harmonised fuel saving calculator which could eventually be posted on each manufacturers’ websites, to calculate fuel savings and compare products