I have been using the shell card for the past 3 or 4 months. 10 visits at about 250 litres a time gives me 6 or 7 pounds off when I fill up my car. It also keeps offering money off the vpower(?) fuel but it is about 20p a litre more anyway so don’t think it’s worth using.
One of the guys in a service station explained to me that using the fuel card the company already get discount on the pump price and would not get to use the card rewards as well. As far as I can make out visiting shell filling stations a lot of drivers are doing it.