The Group Rate System
Car insurance companies rank each model of car in one of twenty groups depending on its characteristics. This group rate is then used to calculate premiums (the higher the rating, the higher the premium). The characteristics are as follows:

• Damage and parts costs: including the likelyhood of damage to the model of car and the cost of the parts.
• Repair times: Longer repair times mean higher costs.
• New car values: the price of a new car is used to identify the higher specification models within a range.
• Performance: owners of cars with better acceleration and higher top speeds are statistically much more likely to make a claim.
• Car security: better security features (e.g. alarms and immobilisers etc) fitted as standard by the manufacturer help to reduce insurance costs.
• Association of British Insurers determine standard group ratings, however individual insurance companies are free to vary from these recommendations depending on their own experience.