The Association of British Insurers (ABI) new insurance group rating system will put more emphasis on the weight of a vehicle, as the heavier the vehicle, the greater the injury to people and property damage.

Large 4x4s fall into the category of heavier vehicles and may see insurance increases when insurers adjust to the new ratings later this year.

The ABI said the new system was designed to more accurately reflect changes in vehicle technology and the range of new vehicles. The system was last reviewed in 1992.

It added that the number of vehicle groups will increase from 20 to 50, reflecting the growth in vehicle types, different repair techniques and materials and a wider basket of spare parts, such as air-conditioning units.

ABI spokesman Malcolm Tarling said: "4x4 owners could pay more but this new system has not been designed to single them out.

"The group rating system is just one factor taken into account when premiums are decided upon. Other factors include the age of drivers, where they live and the type of policy under which they drive."