Are these eco-tec valves a load of balls or do they actually work?? If so how? Oli.

I read alot into these and the general consencus was they are a load of bollox.

I've had a couple now. No difference in power noticed at all but on one of my cars I noticed a slight improvement in fuel consumption. Not worth it all in. In fact I think I still have a brand new one around that I didn't fit to my last car.

Tried one out a while back.
No good on anything with an ecu. I lost performance and fuel economy!