Changes to the MoT have come into effect and could catch unsuspecting motorists out because of the new, stricter criteria.

The standard MoT will now test 15 extra aspects of cars on top of the standard test and this means cars could now fail an MoT despite passing before the updated test was introduced.

Along with insurance and breakdown cover, MoTs are one of several costs motorists will face on an annual basis.

What is the MoT?

The MoT test is designed to ensure all cars currently on the road in the UK are in roadworthy condition. This helps to ensure the safety of drivers and pedestrians on British roads.

It also checks cars meet environmental standards to minimise the risk of pollution across the country.

All cars need to have a valid MoT to be road legal with the exception of cars that are less than three years old.

Once a car reaches three years of age it must be tested for the MoT every year. The MoT is a list of parts that are tested for an MoT is extensive and includes vehicle structure, fuel systems, exhaust emissions, seat belts, brakes, tyres, windscreen, steering and a host of other things.

MoTs take place in authorised garages under the control of the Vehicle and Operator Services Agency (VOSA) which is responsible for maintaining standards in the MoT tests.

What has changed?

The MoT test has changed because cars are more advanced than ever before and feature new equipment and systems that may not have been around when the MoT test was introduced.

Changes to the MoT test include:

Electronic stability control - ESC is now included on nearly all new cars. In fact, it is impossible for a car to get a five-star safety rating without it and as a result ESC is now being tested as part of the MoT for those cars with it fitted.

Electronic parking brake - The electronic parking brake will also be tested.

Steering and suspension - Items such as steering locks and parts of the suspension will now be tested despite most people assuming this is already a part of the tests.

Lights - A car's lights including warning lights for some of the new systems such as ESC will now be checked along with checks to High Intensity Discharge (HID) headlights to ensure they are not dazzling other road users.

Tyre pressure monitors - If the car comes with a tyre pressure monitor it will now be included in the MoT.

Speedometer - Amazingly the speedometer was not previously included in the MoT but this has now been rectified for 2013.

Electric wiring and battery - The introduction of more electrical systems than ever before means the MoT will now cover these from this year. Damage to wiring and the car's battery will be carefully checked from now on.

Fuel system - In a similar vein fuel pipes will need to be in a reasonable condition in order to pass the test.

Exhaust - A catalytic converter is needed to reduce the amount of harmful particulates from diesel engines. Traditionally these can become less effective or damaged if the car is only driven shorter distances and as a result they are now included in the MoT. A replacement converter could cost as much as £700 if a car does fail for this reason.

Doors - If the rear doors of the car cannot be opened from the outside the car will fail an MoT.

Towbars - A towbar will now be checked for the MoT because it could affect the how safe a trailer or caravan is when it is being towed.

Why has it changed?

The host of changes introduced above are now being included in the MoT because the test needs to keep up with changes to car design and advances in automotive technology.

For example, the introduction of electrics into a huge amount of new car features such as ESC and parking brakes mean the old MoT was not fit for purpose when checking potentially life-saving technology.

The changes are designed to ensure the safety of UK motorists and reduce the environmental impact of cars on the road today.

How much will it cost?

MoT tests are compulsory for UK drivers but thankfully the government has placed a maximum cost. For a car this is £54.85 and it is illegal for garages to charge any more than this for an MoT test.

However, it is legal for a garage to charge less than this if they wish.

The cost changes for three-wheel vehicles that weigh under 450kg (£37.80) and for motorcycles. Bikers will pay between £29.65 and £37.80 depending on the engine size of the motorcycle.

Buses, taxis and vans will all have their own maximum price depending factors such as number of seats, weight and size.

The new MoT test changes came into force on 20th March 2013 and all MoTs taken after this will be subject to the new rules.