I noted in the Directory booklet with the January magazine that there is now an ESSO Fuel Card available from Fuelpecker, the link available on the main site. You'll need to sign up via the link as that automatically gives them the validation code during the sign up.
I won't put it here because it's an open forum, but essentially if you click through from having signed into the MMOC members area, then the web address contains the required code.
I used to have an ESSO Discount Card issued via Pump King, which was a fixed weekly price.
In December, They rebranded the business to Fuelpecker and all Pump King card holders were invited to apply for a Fuelpecker Card, which I did.
I've not used it yet, but the big difference is that Fuelpecker offer a fixed rate off the pump price wherever you buy. Although you have to give them a Reg No when opening the account, you're not restricted to that vehicle, you can use it on any. But like all fuel cards, you can only buy fuel using it, not a car wash, newspaper or snacks that you might want at the same time.

I just thought I'd share this as I have no idea when they joined the Member Discounts list. but I assume recently.