A report from automotive supplier sector specialist supplierbusiness.com suggests manufacturers are fast approaching the limits of their capacity to reduce average fleet CO2 emissions reductions, despite devoting as much as half total R&D expenditure to the task.

The problem is partly attributed to conflicting objectives in EU emissions standards, in which particulate and other noxious emissions reductions only come with CO2 and fuel economy penalties, and partly to consumers' preference for buying more efficient new cars with enhanced performance for the same fuel economy rather than sticking with the same power output for greater economy.

The ACEA is said to be resisting pressure from the EU to toughen its self-imposed goal of 140 g/km CO2 by 2008, a target which is based on average consumption of 5.3l/100km for diesels and 5.8l/100km for petrol models. There is talk of pressure to achieve a 120 g//km target by 2012. Average 2002 emissions were 165g/km - a slight rise from the 2001 figure of 164g/km.