which odds to use?

Greetings all,
Let's say you are playing limit hold'em, it is post flow and you figure you have 4outs. The pot is offering you 5 to 1, if you use rule of 4/two cards to come, you have enough to call and see the turn , if you use rule of two/one card to come, you are short (needing 10.5 to 1) Would you use the safer numbers and pass or the "looser" numbers call and re-evaluate on the turn. Hopefully this made sense, thanks in advance [img]/images/graemlins/smile.gif[/img]