i had a zc in my rex. i loved it. it was a super easy swap. very inexpensive engine. over the stock si engine the power is pretty impressive, but after like a month or so you are gonna be like, "damn this isnt that fast after all, i shoulda went with the b16". a friend of mine now has a rex with a b16, we just finished it up and that is awesome. swap was a little trickier, but well worth the extra time and money. so i would have to say if you are on a budget, zc...........and if you can splurge a little bit, b16a. oh and yes, my zc DID use some oil. nothing too bad, but it was noticable. hope this helped you out some.