When buying a car insurance policy, it's common to assume that the facts the insurer is most interested in relate to the car in question and the owner's driving skills. For example, the type of car, how old it is, whether the driver has any motoring convictions, how many years of no claims bonuses she has achieved, and so forth.

However, try to get a quote from any car insurer and you will see they are also interested in you and your lifestyle. For example, they will want to know your age, gender, marital status and postcode.

This is not random demographic information gathered because they want to know their customers better for marketing purposes. They are using this information to calculate your premiums, based on statistics which show the likelihood that a person in your situation will need to claim on the policy.

Logically, the greater the risk is that you will claim on the policy, the higher your premiums will be.

For this reason, it is very difficult to pinpoint a single insurer as offering the best deal at the moment. The cheapest deal for you will always depend on your individual circumstances and situation, as well as the car you drive and your driving record.

But which specific factors affect the cost of your premium? For example, does being married make a policy more or less expensive? If you park your car in a garage, will you pay less? Can female drivers really get cheaper insurance?

According to insurance company Diamond, the reason married drivers pay lower premium is because its data shows that married drivers tend to claim less than single drivers.

On the other hand, despite all the statistics demonstrating that, overall, women are safer drivers and despite all the female-driver-only insurers out there which claim to offer fantastic deals to female drivers, companies like Admiral are in actual fact currently offering cheaper deals for men than they are for women. This just goes to show that, if you are a woman, you should never assume that a female-only insurer will offer you the cheapest policy. An insurer that offers policies to both men and women may well provide policies which are better value for money - so you should compare the whole of the market before you decide which insurer to go with.

Location also plays an important role, a driver in London can pay up to £100 more yearly than an out-of-London car-owner. This is because crime and traffic in London are both higher, making it more likely for car-owners in London to make a claim.

Garage-owners also tend to get lower quotes, again for safety reasons. However this is not always the case. Some car insurance companies, such as Diamond, are not aware of this fact and will actually offer you lower quotes for a car parked in a garage rather than on the street. This is a good reason to check the quote for both street and garage parking even if you do have a garage facility, seeing as this is not always beneficial.

Similarly, the more experience you have as a driver, the lower your premiums will be. This does not just apply to teenagers, even twenty-year-olds get a worse deal than thirty-year-olds, especially if their license is new. This is bad news for new drivers, but no surprise.

Bearing all this mind, it is a very bad idea to choose to lie about your age, marital status, gender or any other personal details on your car insurance quote form. This could potentially invalidate the insurance policy which would cause various long-term problems for acquiring insurance and consequently also for driving.