Regulations are to be brought in by the EU requiring tyre manufacturers to produce quieter and more fuel efficient tyres.

BBC NEWS | UK | Law aims to provide safer tyres

The regulations will come into force in 2012, after the European parliament voted to make tyres 50% less noisy ,and have been welcomed by tyre makers.
Further regulations are being considered for tyre labelling, which would give consumers a clearer idea about the road-grip, fuel-efficiency and noise levels of various companies’ products.

This applies to tyres fitted to new vehicles, but what about replacement tyres?

The following is from a report produced in 2004 by TRL
Tyre/Road Noise – assessment of the existing and proposed tyre noise limits. (PDF)

A further consideration is that the type approval limits currently apply only to OEM tyres, i.e. tyres fitted to new vehicles. The regulations for replacement tyres will be rolled out from October 2009 until October 2011 based on tyre width.

At the present time it is likely that between 25-33% of car tyres will be OEMs, so that most of the noise produced will come from currently unregulated tyres.
If a reduction in the tyre noise limit was applied to OEM tyres today, it would only take about three years before the new limit values tyres were fitted to approximately 30% of the passenger car fleet. If we assume that OEM tyres are fitted to vehicles throughout the first three years of their lives, e.g. while the vehicle is serviced by a franchised dealer during a warranty period, then approximately 40-50% of total UK mileage will be on OEM tyres.

Reductions in noise levels from replacement tyres will filter down to the remainder of the UK vehicle fleet, i.e. the older vehicles. Within two years of reducing a noise limit for replacement tyres, well over 50% of miles driven by the older part of the vehicle fleet will be on tyres meeting that limit.

Interestingly the report states that there would not be a noticable effect on fuel economy or emissions of greenhouse gasses, but the press love an environmental slant on these things.

The report does suggest a ‘special’ class for ‘Big’ tyres, which is good news for the modifiers.

“We are also proposing a new tyre class for the largest of tyres that would be outside this level of 71dB applying to all current classes. The introduction of a new tyre class (i.e. C1f) would be an allowance for the very large tyres fitted to ‘super cars’. These vehicles cover very little mileage and therefore have very little impact upon overall traffic noise levels. For this extra tyre class we have recommended a section width of 245 mm and above, although the exact width would need to be considered further.”

Finally, this subject was discussed in the VOSA consultation on BIVA which makes an interesting link.
See the Department response to Question 10