Why does everyone assume remapping an ECU leads to driving faster? I thought the topic was on preventing DPF problems? The engine which Jaguar put into to your car maybe very well designed? But there not hand built and blue printed,So each will be slightly different but the ECU used is not calibrated to individual engines hence fuel efficient it's not! It stands to reason if you can achieve 3-5 mpg more the fuel is being burnt and not depositing un-burnt down the exhaust. I don't dispute you think your car drives very sweetly as your used to driving it, But I very much doubt after 10 years the bhp would be anywhere near the quoted 208 horses of a new engine and if your happy with the way it drives then all well and good. Before you shot me down! I was just trying to give advice on others not so fortunate to own such a sweet driving model. End of my impute on the subject..