cant compare the panel, but i have a 57i on my 1.8 20v non turbo gti, at the same time as fitted it had its usual 3000 miles mobile 1 oil change, bosch super four plugs, and since then i have noticed a massive increase in mpg, (now if driving at 60mph and limits then now reading 43mpg on maf), as for performance yes id say i can feel a difference, the engine now has a nice revvy sound and dose so easier, it pulls loads better from 4000 rpm upwards than it did do before, below 4000rpm there isnt much difference apart from the sound, i spose pending on what model gti your putting it on it will perform different!!
Gaz
