A: Remapping is virtually untraceable but if it is found it may affect your warranty.
A: Improvements in fuel consumption of up to 20% are possible, especially in turbo diesel powered engines.
A: Tuning boxes fool the ECU in to thinking that the engine requires more fuel by giving false sensor values. Although gains are made this causes bad engine running and poor economy and reduced life of engine components. there is no proper control with a tuning box ie. no rpm input it is just adding more fuel.
A: Remapping takes about 1.5 to 2 hours depending on what vehicle it is.