Supermarkets have both cut the cost of their petrol to under £1 a litre - bringing "Christmas cheer" to motorists.
The Asda price drop - falling by two pence to 99.7p - will last three days at all of its 277 filling stations from Friday.
Morrisons said they hope to keep their price of 99.9p for "as long as possible."
Both stores have cut their diesel to 103.7p a litre.
Tesco and Sainsbury's have also announced cuts to make petrol 99.9p and have taken a penny off diesel.
Asda's current petrol price per litre
Morrisons, Asda, Tesco and Sainsbury's current price per litre.
RAC Fuel Watch spokesman Simon Williams said while the drop would bring "Christmas cheer to many", he wanted to see the low price being held longer than three days.