I thought this was interesting. This website www.4b11t.net talks about the engines on our cars. They have a tech vid on it somewhere, couldn't watch it though cause I'm in class :-(
Actually, our cars have the 4b11. The EVO X has the 4b11t. The 4b11t has a compression ratio of 9:1, whereas the 4b11 (thats in our cars) has a compression of 10:1.