Sainsbury's Bank car insurance index, which provides a comprehensive independent analysis of online car insurance premiums across the UK market, reveals that the cost of car insurance is steadily rising, with the average premium in July 2007 reaching GBP486.43, an increase of 2.9% over December 2006 and 4.2% over July 2006.

Over the 12-month period, the average car insurance premium increased by GBP19.80.

The index indicated that gender continues to have an impact on how much customers pay for their car insurance, with the average premium for men being GBP518.46, compared to GBP442.28 for women. Indeed, between July 2006 and July 2007, the average car insurance premium for men increased 5.2%, as opposed to 3.1% for women.

Age also has a huge influence on the premiums paid by the customers. Unsurprisingly, as they are responsible for the highest frequency of car insurance claims, motorists under the age of 25 have seen the biggest increase in their car insurance premiums, rising by 6.4% since December 2006, and 11.2% since July 2006. In contrast to this, motorists aged over 65 saw the cost of their car insurance only increase by 0.79% and 2.7%, respectively, the lowest rise for any age group.

Lucy Hunter, Sainsbury’s car insurance manager, said: Premiums have been rising steadily and it has been predicted that this year, they could increase by as much as 10%. However, by shopping around, you can still reduce your premiums significantly. Unfortunately, many motorists are not prepared to do this. Our research shows that one in five motorists only obtained one quote the last time they bought car insurance and of those motorists who did not obtain more quotes, 19% said it was because they could not be bothered or didn’t have enough time.