VED road tax increase for next year could be put off by canny motorists who plan ahead.
Instead of there being seven categories of tax rate according to the car's carbon dioxide emissions there will be 13.
Rates for lower-emitting cars will fall by up to 30, while rates for higher-emitting cars will rise by up to 55.
As a result, motorists are being urged to plan ahead and work out whether it is more economical to renew for six or 12 months.
For instance, the owner of a car emitting less than 125g/km of CO2 who needs to renew their tax after November 1, 2008 will benefit by paying for only six months of tax at the current rate, and then renewing again at the lower rate after April 1, 2009.
In contrast, motorists with cars that emit over 151g/km of CO2 would benefit by renewing for 12 months and avoid paying for six months at the higher rate.