British drivers could face a hefty fine for using a common fuel-saving hack on the road.
The technique, known as 'coasting' is defined by Rule 122 of the Highway Code as a vehicle travelling in neutral, or with the clutch pressed down.
Motorists could incur fines of up to £1,000 if they're caught coasting - or as much as £2,500 for larger vehicles.
Driving experts warn against coasting as it can reduce a motorist's control of their vehicle.
The method means that drivers eliminate engine braking, which can lead to a vehicle's speed increasing rapidly when travelling downhill.
This will require increased use of the foot brake, increasing wear on a vehicle's brake discs and pads.
But that's not all - coasting can also make it difficult to select the right gear when needed.
A vehicle's steering response will be affected too, with drivers seeing a difference on bends and corners.
Failure to have proper control of a vehicle can lead to a potential fine of £1,000 or even a discretionary disqualification, with a risk of a driving ban.
For larger vehicles using the coasting method, such as a buses, coaches or HGVs, the fine can be raised to £2,500.
John Wilmot, chief executive of LeaseLoco, says that coasting may be affected by new technology in cars.
He explained: "Coasting is no longer beneficial to energy efficiency due to the fuel system in the majority of modern cars.
"When we drive downhill in gear, our engine ECU detects that the accelerator isn't engaged and cuts fuel from going into the fuel injectors.
"We use no fuel or very little when driving downhill in gear.
"However, when we drive downhill in neutral, our engine and wheels become disconnected.
"This forces a small amount of fuel to be sent to the engine due to the car not receiving the rotational power it needs from the wheels, instead of drawing that power directly from the wheels."
When pressing down on the clutch while coasting, the clutch release bearing is put under stress for longer periods than necessary.
It may lead to drivers having to replace it more often than usual - a complex and costly repair that requires dismantling the entire clutch mechanism and could cost even more in the long run.
Road accidents may rise in the coming months as the cost of living crisis could mean more faulty vehicles on the roads , Halfords has claimed.
The car parts company issued a warning that hard-up motorists could be avoiding trading in old cars for newer ones, putting road safety at risk.
According to the retailers, the average age of cars on UK roads has increased by more than a year to 8.7 years over the past decade as costs have crept up.
But mechanics at Halfords said this could easily pass the 10-year mark in the coming months as inflation soars and energy bills, petrol prices and food costs leave more people feeling squeezed.