your better off going the i4 its chucks out 150ps in standard trim where as the 1.8zetec is about 130ps. the i4 is chain driven not belt and i like any one else with an rs2000 knows the i4 can take loads of abuse. it really is a tough unit. only downside is its getting tricky to get ugrades like cams for the i4 as there isnt loads of them around and wasnt really mass produsedlike the zetec. the zetec is more tunable but your better off going for the 2.0 instead of the 1.8. theres loads in the srappy's and there dirt cheap. (from arond £50 depnding on where you go)