Further measurements of real tyre pressures on passenger cars in use have taken place in the Netherlands between October 2007 and April 2008. The Dutch delegate gave some explanations about these measurements which were conducted mainly by students on the car parks of companies and shopping centers. The owners of the cars were asked if they agree with the measurements and got a refill of their tyres with nitrogen to the inflation pressure recommended by the manufacturer after the measurement. Some more information about the measuremants can be found in doc. TPM-03-06.

The recorded pressure data were sent together with the VIN numbers of the vehicles to OICA and the task force “data collection” for further analysis, also to find out which of the vehicles were equipped with TPMS.

Between February 12, 2008 and June 9, 2008 the task force “Data Collection and Cost/Benefit Analysis” under the chairmanship of Mr.Vim Verhove (CLEPA) had 7 meetings to collect tyre pressure data of vehicles in use in various countries including the data from NL mentioned above, to analyse and to compare these data, to develop a calculation method for the increase in fuel consumption/CO2-emission due to underinflation, to consider the effect of under-inflation on tyre wear and road safety, to find the causes of underinflation and to determine the cost for TPMS.

The latest version of the task force conclusions was distributed as doc. TPM-03-02_rev.1. Mr. Verhoeve reported that the task force had difficulties to determin the cost for TPMS. OICA had tabled some figures but they have not yet been discussed in the group. When discussing the results some experts tried to point out advantages and disadvantages of specific TPMS designs. The chairman stopped this discussion because it is not the task of this group to draft requirements for specific designs of TPMS but to define minimum requirements which will reduce the number of vehicles which are driven with under-inflated tyres.