My 330d is standard as far as engine mods go- I have seen plug in mods that claim to boost bhp by 20/25% and improve mpg at the same time ?
any advice or experiences would be welcome
I am not looking to go stupid at start changing lots of stuff (induction / exhaust etc...) but, if a plug in mod is available and worthwhile i might be tempted - the one I saw was around £130 from CPP (car parts performance)