What would be there best option to go for on...................lets say for instance...........uuummmmmm.......... 2.5 Diesel Turbo Range Rover

Just thinking what will be best out of the 2 options for me.

I Know that if you have a BIG BHP Cossie.Evo/Performance car then Mapping it is DEFFO what to do.

BUT

What about just to gain some power/torque/ drivability and MPG on a diesel??????

What are the pro's and Con's of each option??