Cjm just contradicted most of what CAR just said lol,
But i think what car has said seems to be the general view on 1.8 tuning now days,
6 brakes are well worth the upgrade trust me 266mm's dont cut it lol
All 1.8 xs have the same ECU and thats what couses the issue, so they should all do it,
As for the induction, they only start effecting the MPG when you just wedge it in the middle of the engine bay next to the hot engine, sucking in all the hot air around it. If you but it some where away from heat, where it can suck in cold fresh air , it will improve the car rather than bogging it down and sending the MPG through the roof
But i think what car has said seems to be the general view on 1.8 tuning now days,
6 brakes are well worth the upgrade trust me 266mm's dont cut it lol

All 1.8 xs have the same ECU and thats what couses the issue, so they should all do it,
As for the induction, they only start effecting the MPG when you just wedge it in the middle of the engine bay next to the hot engine, sucking in all the hot air around it. If you but it some where away from heat, where it can suck in cold fresh air , it will improve the car rather than bogging it down and sending the MPG through the roof