You could try a free bandwidth monitor. I doubt you're going to get anywhere near your monthly allowance on even a basic broadband package; I used to play F1 2010 online via a mobile broadband connection with a 4gb per month usage allowance and I would imagine that F1 2011 is pretty similar to 2010 in terms of resource usage.
I think the amount of bandwidth a game like F1 2011 uses is somewhat variable too depending on how much data is being transferred (how many cars etc...), so the best way would be to download a bandwidth monitor and that way you could work out an average for you.