TYRES

Correctchoice of tyre dimensions

Choosingcorrect tyre dimensions is key for ensuring greater safety on the road. Tyredimensions specifications are composed of 4 key factors: tyre width (in mm),aspect ratio (recalculated as percentage of tyre width), wheel diameter (ininches), and the maximum load capacity with the speed category. To make yourselection of tyres easier, check the tyres currently installed on your vehicleand make sure that the tyre dimensions match the manufacturer’s requirementslisted in the vehicle type-certificate.

Tyrelabelling

We preparedthe information on tyre labelling in co-operation with Michelin Slovenia. Tyreclasses for passenger vehicles and van can be determined by manufacturersthemselves on the basis of tests conducted in accordance with approved Europeanprocedures. The European tyre label allows consumers to instantly identifyimportant tyre characteristics. These important tyre characteristics are fuelefficiency, wet grip, and external rolling noise. Since 1 November 2012, alltyres in the sales programme must be marked and labelled with EU stickers.

Fuelefficiency

Fordetermining the fuel efficiency class, Michelin Technology Centre containstesting equipment approved by the European Commission as reference equipmentfor the purpose of tyre labelling (published in the Official Journal of theEuropean Commission, 23 March 2012). Your vehicle can use up to 20% less fueldue to tyre and rolling resistance alone. The key for fuel efficiency ischoosing tyres with a higher class on the EU label, so that you can drive morekilometres and generate less CO2 emissions. Fuel efficiency is marked with acolour and symbol scale from A to G – A (green label) means the highest fuelefficiency, while G (red label) means the lowest fuel efficiency. For passengervehicles, class D is not used.

Michelincompared tyres from classes A and G, saving 200 litres of fuel using a vehiclewith class A tyres driving 40,000 kilometres, which at a price of EUR 1.50 perlitre of fuel represents savings of EUR 300.00.*

Wet grip

TheEuropean testing procedure allows testing in a wide range of temperatures, from5°C to 35°C for “summer” tyres and from 2°C to 20°C for “winter” tyres. To presentaccurate information on performance and in order to consider all methods ofuse, Michelin tests tyres on surfaces that match European guidelines, attemperatures of about 20°C for “summer” tyres and about 7°C for “winter” tyres.This corresponds to conditions most often encountered by European drivers.Michelin has decided not to test tyres at limit temperature values (35°C forsummer and 20°C for winter tyres). Wet grip is marked with colour classes fromA (best grip) to F (worst grip). Classes D and G are not used for passengervehicles.

Michelincompared the braking distance for tyres of classes A and F, and found that thebraking distance for a vehicle travelling at 80 km/h and equipped with class Atyres in comparison to a vehicle equipped with class F tyres can be shorter byup to 16 metres. Performance was measured in accordance with the testing methoddefined in the European Commission Directive 1222/2009. European CommissionImpact Assessment SEC (2008) 2860.

Externalrolling noise

Michelin’snew tyre programmes already comply with stricter requirements regardingexternal rolling noise, which be become effective on 1 November 2016 and willrepresent two black sound waves at most. A tyre with one sound wave produceshalf as much noise as a tyres with two sound waves (noise was measured on avehicle travelling at 80 km/h, with the engine turned off). Sound wave markingson the EU label represent the following noise classes: 1 black wave – silenttyre; 2 black waves – relatively silent tyre; 3 black waves – noisy tyre.

Tyrelabelling is an important initiative that helps end users to better understandthe actual impact of tyres on their life and society in general. However, itdoes not answer all demands of end users, nor does it cover all areas of use.The key role for interpreting other parameters, which affect general tyreperformance and are important for meeting user demand, therefore lies with thedistributers – sellers of tyres.

Recommendationsfor use

Selectingtyres

Whenselecting tyres, we have to consider applicable regulation and recommendationsof vehicle and tyre manufacturer, as well as recommendation of any officialbodies (dimension, load capacity index, speed class, tyre structure). We mustalso consider usage conditions, so that tyre performance matches the user’sexpectations.

If youdecide to change the tyre dimensions, in comparison to initially installedtyres, we recommend that you make sure that your selection complies withapplicable regulations, vehicle technical specifications, conditions of use,and manufacturer’s recommendations (please, comply with applicable nationallegislation). In some countries, a vehicle with such modifications must beadministratively approved.

Used tyresor tyres bought from a third party must be thoroughly checked to ensure thesafety of the user and compliance with applicable regulations.

Werecommend installing similarly worn tyres on the same axle. Some countries alsohave regulations on the greatest allowed difference in profile wear.

In accordancewith applicable legislation and due to technical limitations, it is eithermandatory or strongly recommended that only tyres with the same tread patternare installed on a specific axle.

Temporaryspare wheel cannot be used for longer periods, and the maximum allowed speedmarked on the tyre must be observed. Drivers must adjust their drivingappropriately.

Use oftyres

Neverexceed the technical limit values prescribed for a tyre. Excessive or unusualgeometrical vehicle settings can in some cases affect tyre performance. Poor orincorrect tyre selection can also contribute to excessive wear and tear ofcertain mechanical components.

Werecommend use of four identical tyres on a 4-wheel drive vehicle (identicaldimensions, identical programme, identical CAI). The only exception is if thevehicle manufacturer prescribed different tyres for the front and back axle.

Installation

Correctinstallation – performed in accordance with recommended procedures and incompliance with applicable safety regulations – ensures the safety of peopleand protection of products. Only thus can you take full advantage of tyreperformance. Unprofessional installation can cause damage to tyres and vehicle,as well as injury (serious injury and even death). If installation is performedby an apprentice, they must never do so unsupervised! In any event, it isnecessary to comply with technical instructions of tyre, vehicle, and wheelmanufacturer, as well as any instructions for the machinery or equipment fortyre installation.

Safetymeasures for removing wheels

Whenremoving wheels from a vehicle:

•             If a tyre is part of a dual tyre orif the wheel shows signs of damage, air must be released from the tyres beforethe wheel is removed.

•             Make sure that the tyre temperatureallows safe removal.

•             Comply with manufacturer’srecommendations and instructions.

Safetymeasures for installation

Make surethat the wheel and its components are in good condition. Check compatibility ofdimensions (tyre and wheel). Check compatibility of tyre and wheel, tyre andvehicle, and tyre and usage. Consider the positions, direction of installation,rolling direction, and instructions on the tyre sidewall. If the valve ismetal, check the seal or replace the valve and seal if necessary. Afterinstallation of the tyre onto the wheel, optimal tightening with a dynamometrickey has to be performed in accordance with the wheel manufacturer’sinstructions.

Safetymeasures for filling with pressurised air

Filling thetyre with pressurised air is important – not only for achieving better tyreperformance, but to ensure SAFETY. It is necessary for ensuring the bestperformance of the vehicle on the road (grip, braking) and for maintaining tyrestability.

For fillingtyres with pressurised air, only use appropriate equipment with a built-inpressure cut-off switch. To prevent any risk of injury in the event of anaccident, workers or other persons should not stand in the immediate vicinityof equipment.

Airpressure and driving

Airpressure must comply with the recommendations of the passenger vehiclemanufacturer. The recommended air pressure is listed in the vehicle manual,tyre information booklet, and/or on the vehicle (door, on the fuel cap, on thebodyshell, etc.). Insufficient air pressure can significantly deteriorate theperformance of the vehicle. This is also true for significantly higher pressurein the tyres.

Balancing

If thewheel is balanced poorly or not even balanced, it causes vibrations at variousspeeds. Wheel balancing is therefore necessary to ensure a comfortable ride andmaintaining vehicle and tyre performance.

Balancingequipment must also include the centring system compatible with the hub andmust be calibrated in accordance with manufacturer’s instructions. These twofactors are key for conducting a high-quality balancing procedure in accordancewith manufacturer’s instructions; if neglected, they often cause improperbalancing that results in constant vibrations.

Tyrestorage and maintenance

The tyrestorage area must be:

•             ventilated, dry, at an appropriatetemperature, protected against direct light, sunlight, and atmosphericinfluences

•             separate from chemical substancesand solvents that could affect the natural characteristics of rubber

•             clean and clear of any objects thatcould damage tyres (sharp metals, wood, etc.)

•             tyres must not be stored next toany source of heat, fire, flammable substance, material that could cause aspark, electrical plug (battery chargers), or any ozone sources (transformers,electrical motors, welding equipment, etc.)

If tyrescan be stacked on top of each other, it is necessary to make sure they retaintheir shape. If stored for longer periods, they need to be reshuffled from timeto time. Do not push tyres under other objects. Store equipment in original packaging,on a surface without a risk of cuts, tears, or punctures. Always handle tyresand other equipment with tools and equipment that will cause no damage totyres.

Short-termstorage (up to 4 weeks)

Tyres canbe stacked on top of each other; pallets are best suited. Stack height shouldnot exceed 1.2 metre. After 4 weeks, the tyre order in the stacks needs to bereversed. If tyres are fitted to wheels, they must be stored filled withpressurised air and in a vertical position, on a single-line rack.

Long-termstorage

Tyres arestored in a vertical position on racks at least 10 centimetres above the floor.Tyres need to be moved (rotated) slightly every month so that they retain theirshape.

Longervehicle immobility

If avehicle is not used for a longer period, we must regularly check the airpressure and adjust it to match the values recommended by the manufacturer.

Checkingwear and tear

Tyre wearand tear should always be checked in multiple places. The check can beperformed with a tyre tread depth gauge or by checking the wear and tearindicators on the tread patterns (if present, they are marked with a symbol onthe sidewall).

If tyrewear exceeds the legal minimum tread depth, the tyre needs to be removed andreplaced. If you notice unusual tyre wear and tear or varying wear and tear oftyres on a single axle, you need to consult an expert.

Repairs

Tyres canonly be repaired by a qualified professional. Before repairs, the tyres must bethoroughly checked by a specialist – tyre expert. Not all damage can berepaired.

Tyres thatwere used with insufficient air pressure can have irreparable damage. Only bythoroughly inspecting the interior is it possible to determine if a tyre canstill be used. To fully determine the damage and potential repair options, itis necessary to remove the tyre from the wheel.

If the tyreis punctured, an injection of sealant through the valve is often just a partialand temporary solution. These products can cause compliance problems for thetyre, wheel, valve, air pressure control sensor, etc. It is necessary to complywith manufacturers’ instruction. In such an event, it is necessary to consult aprofessional, who should examine the tyres and, if possible, repair themaccordingly.

Advice fordriving in winter

Wintertyres have better performance in winter conditions than summer tyres. Whencomparing braking distances with summer tyres at low temperatures on a wet roadsurface, the braking distance at the speed of 80 km/h can increase by 4 or moremetres. When braking with summer tyres on a snow road surface at lowtemperatures, the braking distance at the speed of 50 km/h can increase by 30or more metres.

AllMichelin tyres are certified M+S or 3PMSF. 3PMSF (three-peak mountain withsnowflake) certified tyres are the only tyres with a winter performanceguarantee, as they are designed for use in snow and fulfil all strictrequirements, as proven by third-party tests. In accordance to European rules,M+S (mud and snow) tyres are “winter” tyres, but their performance in winterconditions has not yet been tested.

Inaccordance with regulations, winter tyres M+S can have a lower speed categorythan the original tyres; driving speed must therefore be adjusted to thepotentially lower speed category. The label warning the driver about the reducedspeed must be attached in the vehicle interior, in a location clearly visibleby the driver.

Wintertyres need to have at least 3 mm of profile to be allowed in winter conditions.Tyres suitable for winter conditions should be used between 15 November and 15March. We also recommend that you replace a tyre after five years of use on avehicle with a new tyre, since the old one no longer has the optimalcharacteristics on the road.