[GTO]

As good as the increased power is, I am not too sure about the diesel powerboxes increasing fuel economy or reducing emissions. Fundamentally, what they do is feed more fuel to the engine (by lying to the ECU). Also, some brands increase the fuel supply ONLY at high rpms.

I and Rt were baffled at the fantastic effect the box had on his Octavia. So we sat and did a little research together on briskoda (awesome community for…..well, Skodas). There were few complaints from people who had used the power boxes. Those who did had problems of excessive smoke (unburnt fuel) and shortened fuel pump life. More fuel also results in raised fuel temperature, with some complaining of a fuel temp sensor gone bad. More than anything, it may be the higher emissions that stop manufacturers from adopting this specification as standard.

Then, there are some manufacturers who will intentionally detune the engine (planned obsolescence), only to offer the exact same engine with a higher power spec later. This typically comes with a face lift and a higher price tag. Case in point? The C200 CDI and the C220 CDI. Identical engines except for the mapping.