I have two of these, one on my k12 160sr and one on my k13 1.2, not done any dyno testing or anything like that but the engines feel slightly stronger, particularly low in the revs. The main difference I have noticed is the popping and banging caused by this, due to the fact that I have modified the exhausts on both of my cars. They also have a dial for adjustment, which I know works, as the MAF rate and intake air temperature change when the adjustor is moved. I wouldn't say the change is anywhere near 10% but all my mates are amazed that I have 2 Micra's that pop and bang!
