Not saying anything new here, but I never ask for gas $$, nor do I expect it. It is normal for my "guests" to buy sandwiches and beers....I take care of the rest. If we go out and stop somewhere with the boat, usually they will offer to pick up a drink or two, which is fine with me.
Poker runs are different. If I do a poker run I will normally set it up in advance with a buddy or two who are willing to split the entry fee, the understanding being that any winnings will also be split evenly. Seems to keep the costs down and there is some incentive to want to chip in (splitting the pot!). Otherwise I pick up all the other expenses.