PetrolPrices.com is a service which aims to direct you to the cheapest petrol prices in your area.
Simply entering your postcode will show you the highest, lowest and average prices for petrol within 10 miles of your location, but to find out which petrol station actually is the cheapest, you will need to sign up. Although signing up is free, you will need to hand over some personal data, and you may get sent some promotional emails from time-to-time.
Once registered, you will have full access to the service, and will be able to find the cheapest petrol in your area. The coverage is pretty comprehensive, and does include the majority of petrol stations. Also, the prices are accurate to within a few days, as they are regularly updated.
Although the service might not be 100% accurate, it is certainly a help when it comes to choosing where to fill up, and if you spend a lot on petrol then the site will certainly be of benefit.
This post forms part of the Money Saving March series.