Background Road transport generates more than 20% of all CO2 emissions in the European Union, with passenger cars being responsible for more than half of these emissions. Furthermore, because of a significant increase in traffic, CO2 emissions from road transport have risen by more than 22% since 1990. This represents a major concern to the EU, which aims to achieve an average CO2 emission for new cars of 120 g/km by 2012 and 95 g/km by 2020. The contact of rolling vehicle tyres with road surfaces creates a drag force known as the ‘rolling resistance’. Any reduction achieved in rolling resistance means lower fuel consumption and related CO2 emissions. Objectives This was a partnership project involving Goodyear Luxembourg (the project beneficiary), an Italian company, Novamont; and a German carmaker, BMW. Bio Tyre’s overall objective was to demonstrate a substantial reduction (up to 30%) of the rolling resistance of a tyre thanks to the combination of the development of new advanced materials and the optimisation of the tyre structure. The first component of the project was to develop an alternative to traditional non-renewable fillers, such as petroleum-based carbon black or mineral-based silica, used in tyres for their reinforcement properties. The new biofiller would be made from renewable resources (a new starch-based material developed by Novamont), thereby reducing the environmental impact and allowing subsequent reductions in CO2 emissions during its production and use phase. The project’s second component consisted of an in-depth analysis and modification of the tyre structure, aimed at minimising energy loss through rolling resistance. while the vehicle is in motion. This will also lead to a reduction of fuel consumption. A final phase was to incorporate the developed new material and use the results of the optimisation of the tyre structure to develop prototype tyres to be tested at the beneficiary's technical facilities in Luxembourg. After this, the best prototypes would be sent to BMW for further testing under real life conditions. Results The project successfully achieved all its goals over the 42 month project period. A new ‘bio-tyre’ with a BioTRED filler was developed, and the tyre structure optimised. Thanks to these actions, the project was able to gain a higher than targeted, 34% reduction in rolling resistance, without any loss in safety, vehicle handling performance or longevity. A major problem during the project was to achieve an acceptable dry braking distance, while reducing the rolling resistance. This was resolved by altering the treads in the tyres. The main environmental benefit of BioTyres will come once they are fitted to cars and in use. The beneficiary estimates that a 30% decrease in rolling resistance corresponds to a 5%-6% decrease in fuel consumption. Considering a typical average run distance in Europe of 40 000 km/yr run by 1 million BioTyres, this would mean a saving of the equivalent of 80 000 tonnes/yr of CO2. Moreover, the production process of a second generation of biofiller (developed by the LIFE project) has an even more positive CO2 balance, compared with the first generation: the absorption capacity through photosynthesis of the corn starch being greater than the CO2 rejected during its transformation process into a biofiller. In contrast, the production of carbon black is a significant source of greenhouse gas emissions. Italian partner Novamont, a specialist in the production of bioplastics from renewable raw materials of agricultural origin, was responsible for the development of the new industrial biofiller. Made from nano-particles of corn starch, it is designed to partially replace the non-renewable fillers such as carbon black and silica. As well as producing and testing experimental grades of biofiller (more than 80 new materials in total), Novamont was also responsible for validating the second generation of BioTRED filler, in order to provide the project beneficiary with sufficient materials to produce the first tyres for testing. The aim with these new grades was to significantly improve the tyres’ rolling resistance while maximising the renewable raw material content in the biofiller, thereby improv¬ing interface properties, reducing weight and minimising costs. An additional benefit is that BioTyres incorporate the beneficiary's ‘run on flat’ (ROF) technology, which means vehicles only require four tyres (no spare) – another resource saving and weight reduction – that should help to keep costs down for motorists, as well as improving safety (by maintaining car control after sudden air loss). Importantly, since the project finished, Goodyear has moved from pilot phase into production. Partner BMW foresees using BioTyres in new car models (e.g. for the 2012 BMW 3-Series) and there has been considerable interest from other vehicle manufacturers. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).