The task force under the chairmanship of Mr. Wim Verhoeve (CLEPA) had successfully collected tyre pressure data measured on passenger cars by various organisations in various countries (NL, F, GB, J, EU). The collected data and the calculation of the changes in rolling resistance, fuel consumption and tyre wear (which had been prepared during two meetings of the task force) have been distributed and explained by a CLEPA-member (see doc. TPM-02-02). The group thanked CLEPA and the other members of the task force group for their good job which will allow as a next step the drafting of cost/benefit analysis for different TPMS.

There was some criticism of the data, because the determination of under- or over-inflation was made in different ways (comparison of the real pressure values with the lowest or highest values of the recommended pressure [loaded or unloaded], temperature compensation). The CLEPA paper shows that an exact calculation of the potential for improvement is not possible because the results are influenced by the driver’s behaviour (distance and speed with under-inflated tyres, reaction on the tyre pressure warning signal). Nevertheless, within a certain range, the calculation can figure out the increase in fuel consumption and tyre wear caused by under-inflation.

OICA will try to get some more information about the increase in fuel consumption depending on the availability of TPMS by comparing the tyre pressures on vehicles with and without TPMS.

As a next step the calculated increase in fuel consumption and tyre wear will be used to establish cost/benefit analysis for various TPMS. Mr. Hesse offered the conduction of this analysis by BASt (Bundesanstalt für Strassenwesen), a scientific organisation which belongs to the German Department of Transport and which has a great experience with cost/benefit analysis.

Several delegates, however, were of the opinion the analysis should be made by the task force group which had collected the tyre pressure data because the members of this group now know a lot about the data and can contribute to the cost/benefit-analysis.

It was agreed, that the analysis will be made by the task force group and BASt will join the group and contribute with its specific knowledge.