Is there such thing as temp. fuel ration in Belgium for personnel from Germany?

We're planning to travel from Germany to Belgium and wondering if we can get (ration) gas coupon for the time we visit. I heard that if you're on leave, you can get temp. ration (amount limited) when you visit Germany from other European country or so. I can't find anything about temp gas ration related stuff for Belgium. I know I can only use my Esso card in Germany... can anybody help?