Right now, it's being reported (via Sky News) the average price of unleaded petrol has hit a record high - now costing 178.50p a litre "p" means pence). That is $2.231 in US Dollars.
The price of diesel has also increased to 185.20p a litre. That is $2.314 in US Dollars.
The math looks like this:
178.50p a litre X 4 (four liters make over 1 Gallon) = 714p or $8.924 in US Dollars.
185.20p a litre X 4 (four liters make over 1 Gallon) = 740.8 or $9.256 in US Dollars. https://news.sky.com/story/petrol-prices-keep-climbing-to-new-record-adding-06p-in-24-hours-12629247