Workshops should expect to be providing a lot of coil packs this winter after AA Warranty highlighted a list of components most likely to break.

The study revealed that the ignition coil pack, the transformer that provides voltage to fire a car's spark plugs, is the component on a car most likely to break in winter.

Analysis carried out by the company on 45,705 claims collated between October 2006 and March 2007 revealed that 13% of all breakdowns suffered by motorists could be traced to a faulty coil pack.

The AA Warranty research found that the second most common problem was a blown cylinder head gasket, with 8% of the claims, followed by a faulty alternator on 7%. The full top 10 list of components most likely to break in winter is below:

1 Coil pack - 13%

2 Cylinder head gasket - 8%

3 Alternator - 7%

4 Starter motor - 5%

5 Coil springs - 3.8%

6 Electric window motor - 2.8%

7 Water pump - 2.8%

8 Air flow meter - 2.5%

9 Wheel bearings - 2.4%

10 Central locking - 1.3%