apparently it gives you better fuel econemy,and better trottle response.
seen here

http://www.btinternet.com/~madmole/Revues/ecotek.html

2001 mondeo st24 rsap saloon,piper x cone filter,pro flow 75mm maf,cta,svt tb,silicone engine hoses,ecotec valve,twin cat back zorst,17 inch bsa 214 alloys,lowered 40 mm,st200 full interior