Wibble wobble Diesel Jelly on a plate

The switch to diesel cars during the noughties has been huge. This has been fuelled (groan) by a company car taxation, the desire of drivers to switch to cars with lower Co2, the allure of higher mpg and because they got better and more fun to drive

With such a switch have come some unforeseen perils. The biggest to date has been miss fuelling (I'll save that for now) but in these extreme cold weather the risk of diesel freezing or more accurately turning t jelly, is real.

With -20C forecast in some parts of the UK, the IAM (Institute of Advanced Motorists) is warning drivers of diesel cars to remember that their fuel can wax over in extremely low temperatures, which could damage the fuel filter and lead to a breakdown.

Neil Greig. IAM Head of Policy and research said: "waxing is the formation of crystals in the diesel which block the filter

If you drive a diesel vehicle it pays to try and park it in a garage or sheltered area, and try not to leave your vehicle unused for too log"

"If you can't park in a garage, try to park so the front of the car is pointing out of the wind. After starting the engine, let it idle for 10 minutes before driving of, as this will let the heat from the engine warn the filter and pipes."

Another risk is where water or condensation builds up in the fuel tank. This though is easily combated by keeping the fuel tank full.

There are additives that can be bought, but sadly these must be added before the problem occurs and there might be some warranty issues, so read the labels carefully. Some people advocate the use of hairdryers on frozen pipes but I am reticent of using any indoor electrical appliance outdoors, especially stood in a foot of snow. If you have a problem the best answer, for those with with home start cover, is to call your car breakdown provider

So with colder weather forecast it just might be worth starting your diesel car and letting it run for a bit, before tucking it up, out of the cold. After all jelly really is best for birthdays