well Si was produced from 99-00 So im taking u live in canada where the Ex is clasified as the Siand Si as a SIRSo willl all that said n done a brand new Civic EX in the US was 12-15gzNow adays they go from 1-5gza Si in US goes from 4-8gz im not sure how to switch the $ between us n Canada but i think its only like 2-5gz diff