yes depending on what grade you buy... yes that's about right...
Currently at my local garage unleaded 95... which is the cheapest is £1.29 per litre... = 3.5 litres equal a US gallon and that equates to £4.90 ...Sterling... which is approx $6.60 USD...however a gallon in the UK is 4.5 litres.. so a Gallon of fuel for us using the same cheapest fuel would be £5.80 which is $7.92 USD which is exactly what you worked out....
Middle range fuel is 97... octane , and that is a few pennies more per litre...
Super unleaded is currently £143.9 per litre..... at my local garage, and diesel is £141.9 per litre... = £6.38 per gallon $8.71 USD
These are the lowest prices... garages and supermarket forecourts all set their own prices..so currently depending on where we go for our fuel we can be paying anything between £1.29 per litre... to £1.50 per litre.....