L 142/26 Official Journal of the European Communities 5.6.1999 COMMISSION DIRECTIVE 1999/52/EC of 26 May 1999 adapting to technical progress Council Directive 96/96/EC on the approximation of the laws of the Member States relating to roadworthiness tests for motor vehicles and their trailers (Text with EEA relevance) THE COMMISSION OF THE EUROPEAN COMMUNITIES, Having regard to the Treaty establishing the European Community, Having regard to Council Directive 96/96/EC of 20 December 1996 and Article 7(2) thereof on the approximation of the laws of the Member States relating to roadworthiness tests for motor vehicles and their trailers ('), (1) ~ Whereas the first auto-oil programme (?) identified the standard of motor vehicles’ mainte- nance as a key constituent in traffic’s effect on air quality; (2  Whereas Section 8.2 of Annex II Directive 96/96/EC to specifies the tests to be carried out at periodic inspections to check that vehicles are properly maintained; (3)  Whereas Section 8.2.2 of Annex II Council Directive 92/55/EEC (°) to specifies that, from 1 January 1996, diesel vehicles need to be tested for the opacity of the generated exhaust smoke during a transient, ‘free acceleration’ engine test where the engine is accelerated against its own inertia; (49 Whereas, this Directive establishes a technical adaptation that will improve the performance of roadworthiness testing of diesel engined vehicle emissions; ()  Whereas, further work needs to be done in the field of developing alternative test proce- dures to check the maintenance conditions of diesel engined vehicles, particularly concerning particulates and NO; (6) Whereas, the provisions of this Directive are in accordance with the opinion of the Committee for the Adaptation to Technical Progress of the Directive on Motor Vehicle Roadworthiness testing established under Article 8 of Directive 96/96/EC, HAS ADOPTED THIS DIRECTIVE: Article 1 Directive 96/96/EC is modified as follows: Annex II, point 8.2.2 is replaced by the following: ‘8.2.2. Motor vehicles equipped with compression ignition (diesel) engines: (a) Exhaust gas opacity to be measured during free acceleration (no load from idle up to cut-off speed) with gear lever in neutral and clutch engaged. (b) Vehicle preconditioning: 1. Vehicles may be tested without preconditioning although for safety reasons checks should be made that the engine is warm and in a satisfactory mechanical condition. () OJ L 46, 1721997, p. 1. (%) Tripartite programme between the oil and motor industries and the European Commission services aimed at developing vehicle emission and fuel quality standards for the year 2000. () OJ L 225, 10.8.1992, p. 68.