On a cold and frosty morning you might think it necessary to leave your engine running to let it warm up - but as technology has progressed over the last 20 years - it could in fact do more harm than good.

The practice of idling your engine to warm it up is from the days of carburettors - a device that mixed air and fuel for internal combustion.

Generally, cars do not have this any more, according to the Manchester Evening News who spoke to specialist motor site Road&Track .

Find out why it could damage your vehicle.

Why you don't need to idle your engine

Engines are now fuel injected and a better approach is to simply drive away immediately. Gentle driving warms the engine quickly without putting too much load on it before reaching operating temperature.

Can idling cause damage?

Yes, idling for too long on a cold day can cause engine oil dilution.

While you might have thought that letting your car slowly warm up was reducing the strain on the engine, all that idling time leads to raw gasoline seeping into the oil, breaking down the oil's lubrication properties and increasing the wear.

The RAC said: "Idling increases the amount of exhaust fumes in the air.

"These fumes contain a number of harmful gases including carbon dioxide, which is bad for the environment and contributes towards climate change, as well as a range of other harmful gases including nitrogen dioxide, carbon monoxide and hydrocarbons - which are linked to asthma and other lung diseases."

Can I get a fine for idling?

Leaving an engine switched on when a vehicle is parked is already an offence, according to the RAC.

The Highway Code rule 123 ‘The Driver and the Environment’, says that drivers must not leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road.

Local authorities can issue fixed penalties of £20 for emission offences and stationary idling (under The Road Traffic, Vehicle Emissions, Fixed Penalty, England, Regulations 2002), however this is only done if the driver refuses to switch off the engine when asked to do so by an authorised person.

Here's how you can safely de-ice your car:

1. Turn on the engine.

It sounds obvious, but before you do anything get your engine on. The most effective way of de-icing your car is to flick on the air-conditioning and let it circulate in the car.

2. Do not leave the car unattended.

Owners who leave their engines running while they run inside to grab something they’ve forgotten are a car thief’s dream - and also breaking the law. Drivers have to be ‘in control’ of their vehicle at all times. If you need to go back into the house you should turn off the engine, lock the car and head in. Car insurers rarely pay out if the keys are left in the car.

3. Get rid of any snow.

Use a brush to wipe off all the snow from the car, making sure the front grille is clear.

4. Start de-icing the outside.

Make sure you keep a scraper and some de-icer in the car for mornings when you are stuck. As the engine warms the car from the inside get scraping from the outside. Don’t wipe windows with your hands - your mitts will leave greasy smudges.

5. Never use boiling water on glass.

The rapid expansion and contraction of the ice can cause the screen to crack.

6. Wait until all the glass is clear before you drive off

It’s worth waiting an extra few minutes to make sure your car is safe to drive before you head out in the icy weather.