This project include three major parts: (1) collect data for the automotive noise control regulation of European Union, (2) the discussion on 5th stage noise control criteria of R.O.C. (Taiwan), and (3) the evaluation of tire noise control in R.O.C.(Taiwan). For the development of EU regulations harmonization, the controversy of limit value for ECE R51 still need sometime to coordinate. About the ECE R41-04 , TUV NORD suggested a new roadside pass-by noise test process in order to improve the sift efficiency of illegal tampered silencer vehicles. About the ECE R117, the issue of tire wet grip requirement was inserted into discussion during 43th session. We perform and collect all of test results which were done in the last three years to compare the difference between ECE R51-03(draft)、ECE R41-04 (draft) and CNS 5799 (2003 version). The major conclusion includes: For small car like coupe and MPV, the noise level will be 2dB(A) lower than the CNS 5799. For wagon, trucks, the level is 3dB(A) lower compared to CNS 5799. For motorcycles, ≦175c.c. is 4dB(A), >175c.c. is 6dB(A) compare to CNS 5799 test standard. If we predict the limit value of 5th stage by shift the noise difference form 4th stage and compatible to the new suggestion limit from WP29. We find most vehicles can pass the new limit value proposed by WP29, except the motorcycle, which the limit value still not published. For the affect of in-use vehicle, we compare the two methods and find the similar trend that: in-use vehicle will be 2dB(A) higher than new car. Therefore, the criteria of 5dB(A) higher than new car will still be suitable. The technology of tire companies in Taiwan is good enough to pass ECE tire noise standard. There will be no obvious impact by importing the ECE tire noise control regulation now. But importing new regulation scheme need many cost. In order to fit the tire noise regulation enforcement in EU, many tire companies introduce projects about how to develop low noise tires. Therefore, before introduce the tire noise control regulation into Taiwan, the issue of how to help tire companies to development low noise tire may be more important.

Automotive noise measurement; Tire noise; Noise control criteria