So as far as I am aware there are 3 main stages of mapping the ECU, a standard 2.5 TD5 engine runs around 120bhp, with a stage one and no other modifications you should be in the region of 160bhp, a stage 2 takes you up to around 190bhp but you need to blank the EGR, fit an uprated intercooler and remove the mid silencer box. A stage 3 is more power again, I am not sure exactly what bhp you get as I have never looked into it, but I imagine it’s a big jump from stock, meaning probably a beefier clutch, perhaps a bigger turbo, and as the old saying goes if you have a whole lot of go you need a whole lot of wow.
this is all done with retuning the ECU, I would only go to reputable technicians to do this and am no expert but I have read that manufactures always leave a bit more poke in the engine so if they bring out a facelift model they can unleash some more power from the same engine and claim it’s been improved.
a stage 1 would be a real good all rounder without a whole lot of fuss, but a stage 2 is the same price and a bit more fun, admittedly there are other upgrades you need to do but I have pretty much done them all already.
Everyone I speak to with a stage 2 says they are brilliant and none (so far) seem to have had any issues, but most people with a stage one seem to say they are thinking about a stage 2. So I am thinking why not just jump straight to a stage 2?