Executive Summary

1 Tyres are the most visible safety features on vehicles, responsible for a significant proportion of the available handling improvements of modern vehicles. Tyres are used in a wide range of different vehicle markets not just private car or commercial vehicles. They are specifically manufactured for Motor Racing, Van and Light Truck, Motor Cycle, Bicycle, Earthmover, 4x4 and Sports Utility Vehicles (SUV), Taxi, Multipurpose Vehicles and many more. For each of these categories tyres must be designed so that they are "fit for purpose".
For simplicity and clarity this report concentrates on car and commercial vehicle sectors although it recognises that varying market factors will apply to all these disparate vehicle categories.

2 As essential items tyres are highly engineered and designed to provide continuous traction, whilst providing grip and comfort under high loads (for commercial vehicles) and for long periods. They must perform in extremes of temperature, on dry, wet or frozen conditions, as well as under variable loads and road conditions. Tyres can not always be changed to suit these different conditions and are designed to meet a "middle course". Consequently, direct comparison between brands is often impossible, although some brands are sold for a particular purpose, for example winter conditions or grip.
To respond to so many different demands a tyre must be constructed from durable materials which can provide these properties. For this reason tyres are rubber composite structures which can include steel wire and textile materials, to provide strength and physical durability. Tyres are often replaced because of tread wear rather than structural failure.
In an advanced industrial and service based economy such as the UK a large number of waste tyres are produced every year. In 2001 the total number of used tyres in the UK amounted to 481,000 tonnes of which 290,000 tonnes were recovered, reused or recycled. The remaining 191,000 tonnes were sent to land-fill, stockpiled or illegally dumped.

3 The management of this growing environmental burden needs to be improved, particularly with the imposition of a total ban on the disposal of tyres to land-fill in 2006. Retreading is one of a number of options that is used to manage this burden, however the practice, and its image, has been much maligned. This study provides a comprehensive review of retreading which covers the process, the economic and environmental benefits, the challenges faced by the UK retread industry and how effective measures can be taken to improve the prospects for the sector.

4 Retreading is a widely practised procedure which entails the careful removal of a worn tread from the used tyre surface, followed by its replacement with new rubber compounds. Most tyres manufactured for commercial vehicles and some tyres produced for cars, can be reused by adding new tread because of the inherent high quality and durability of the tyre's structure.
Some commercial vehicle tyres can be retreaded 3 or 4 times extending the operational life to 600,000 kilometres thereby maximising the use of the materials and energy required to make each tyre. (Car tyres are only ever retreaded once). In addition to the resources saved by this process, and the reduction in the quantity of tyres that must be scrapped, there are clear commercial benefits to fleet operators. For this reason retreading is an accepted procedure in the commercial sector and some other applications such as aviation, earth moving and motor cycles. Consequently, the annual market for retreaded commercial vehicle tyres has remained relatively consistent since 1995 at ~1,000,000.
Retreading is also becoming an integral part of tyre management services for large fleet operators. This is a logical direction and offers considerable advantages to all the stakeholders involved.

5 Despite the relatively buoyant commercial sector the home and export market for private car tyres has declined from 7.5 million in 1995 to 1.5 million by 2001. This sharp decline can be partly attributed to the poor image of retread tyres, however, the expansion of low cost producers in the Far East has led to an influx of new car tyres at highly competitive prices. Some of these tyres are designed with structures that last about as long as the tread and consequently are unsuitable for retreading. This feature not only increases the numbers of scrap tyres but also diminishes the available stock of retreadable casings.

6 This study has also highlighted that, despite the challenge of cheap imports, some retreading companies have successfully sustained high value or specialist niche markets for car tyres. Retreaded tyres can be made to virtually any specification and, if marketed through independent and knowledgeable dealerships, can be sold with confidence. The general lack of awareness of tyre properties such as grip, wear, economy and speed rating by private car owners may partly explain why choice is largely governed by price. Better information backed by an energy rating system akin to domestic white products may help to improve the prospects for retreaded tyres in this sector.

7 The negative image and historic quality issues have led to the introduction of stringent and highly prescriptive quality control regulations (ECE 108 and ECE 109). These internationally recognised regulations stipulate not only the process and quality control during manufacture but also the testing regime that is required to enforce consistency through independent verification.
Moreover, the quality of retreaded tyres can now be checked by a series of sophisticated non-destructive techniques such as shearography and ultrasonic scanning which complement manual inspection and inflation testing. Yet in spite of tight regulation, environmental benefits and competitively priced products, private motorists are largely unaware of retread tyres or still have a false impression of them. There is some evidence that this image is promulgated by tyre retailers.

8 Improvements in retreading have clearly demonstrated that tyres can be made to virtually any specification for both private and commercial use. Retread suppliers, some retailers and end users accept and use retreaded tyres because they offer reliability and good performance at a competitive price.
Claims that tyre failure, rolling resistance and fuel usage are increased as a result of retreading are equivocal. Factors such as driver behaviour and tyre maintenance, especially inflation pressure, are known to be far more significant influences on fuel economy and tyre failure. The resultant tyre debris from sudden failure is often wrongly perceived to be associated with poor quality retreaded tyres rather than a lack of vigilant tyre care.

9 This study has clearly demonstrated that retreaded tyres offer clear environmental and commercial benefits. These benefits are widely acknowledged by large fleet operators, taxi fleets, for example London Black Cabs, and even by the US Government where for example school buses and military vehicles are fitted with retreads.
These positive features, and the contribution retreading can make to overall responsible reuse and disposal options needs to be actively and widely promoted. Adoption by UK Government agencies, local authorities and other organisations involved in public procurement would also help to endorse the use of retreaded tyres.

10 A major barrier to the uptake of car retreads is the resistance of car manufacturers to supply retreads as original equipment. Reasons for this include tied relationships with new tyre suppliers and market image. A possible solution to this current status may be the promotion of special "green consumer" models by responsible Original Equipment Manufacturers.

11 The environmental benefits and impacts of retreading were investigated by six audits to companies specialising in the service. The results were complemented with background research on tyre manufacture, reuse and disposal. Every retread cycle for a commercial vehicle tyre saves ~60kg of materials plus an inherent energy saving of ~37.4 kWh that would be lost it were scrapped. For every car tyre that is retreaded an average 5.9 kg of materials and ~4.7 kWh of energy is saved.
Retreading only defers inevitable disposal but it does reduce the quantities of tyres that would otherwise need to be scrapped. Of the approximate 49,000 tonnes that are retreaded in the UK an estimated 13,200 tonnes of tyres for commercial vehicles could be reused if there were better selection procedures and improvements in tyre use. Significantly ~75,000 tonnes of car tyres could be reused if the 1995 quantity of retreaded car tyres could be matched.

12 An important and less obvious environmental benefit of retreading is integration with used tyre disposal, adding a vital stage to a resource efficient tyre life cycle. In order to retrieve sufficient quantities of worn tyres that are of suitable quality for retreading between 70-90% of each batch may need to be rejected. This may seem an inefficient process however it highlights the responsible disposal service function that retread companies can offer.
Some retread companies have integral recycling plants that separate scrap tyres into their component materials for reuse. Crumbed rubber is used for carpet underlay and can be used to make absorbent surfaces for sports centres. Shredded rubber and textile material is used in equestrian centres and steel wire can be recycled.

13 A review of tyre disposal options has shown that retreading has the least environmental impact compared with other disposal options. Eventual disposal of retreaded tyres, along with all other used tyres, needs to be rationalised further to comply with the total ban on landfill disposal by 2006. Duty of Care and the End of Life Vehicle Directive will increase the pressure to find responsible alternative disposal routes for all used tyres.