cheers bacillus
would you consider the 'small' catch can to be sufficient?
and if it fills up fully is that an issue?
I think the smaller can is more than adequate for most folk provided you drain it every 1500 miles or so initially.
What's captured in the can really varies from car to car, what type of driving you do and time of year (you collect more during the colder months vs summer). You should get a feel after 2-3 draining on how much "stuff" you're collecting though I do wish the can came with a view window.
If the can fills up then only the excess collection after that point will go back through the return hose to the inlet valve port but hopefully with due diligence it should never get to that point.