Fuel card suppliers are bandits (feul genie aside). They'll lure you in with 5p below pump prices but slowly creep your prices up. Fuel genie just gives you pump prices.
My advice; get at least 2. Once they notice you've stopped using their card, they'll drop the price. You'll get an email informing you next week's prices every Friday, pick the cheapest. Also, when you sign up specify that you won't pay an annual charge and you want the cards issued free of charge, they'll agree but make sure you get it in writing.
Run properly you'll save around 2-3ppl.
Maybe it’s me being thick but I just don’t get fuelcards unless you have a large fleet. An average fill up on a van is around 75-80 Litres. If you save 2p a litre the savings in my opinion are negligible especially if you have to go to a certain fuel station. Surely a Credit Card with cashback or a loyalty scheme is better value?
My saving is somewhere in the region of £500+ p/a off a £30k fuel bill. Not amazing but if you get a system put in place it's not like it's any hassle. My fuel bill is only going up but so too is the saving. If I could save £500+ on any other bill I wouldn't even think about it.
Most fuel cards are accepted in multiple stations although that's not really an issue for me because fuel stations are few and far between round here. UKfuels and Keyfuels are nationwide and accepted in most supermarkets. Both cards are sold by multiple companies.
There are other benefits offered with some of the cards, MPG analysing and vehicle tracking devices for example.
To make credit cards work I'd need 9 or 10 of them, technically, they'd need to be in different names that would need to be replaced on changeover of staff. There is also a (minor) trust issue there.