didnt they do a 2.5 v5 for the gti in america?
Correct and no idea.
It's an in-line engine, not a V5. It's a torquey under-stressed US friendly engine putting out 170lbft/150bhp. Nothing special and drinks petrol but meets the demands of the unsophisticated American mainstream market. They sound quite good with an aftermarket exhaust though.
The basic engine architecture was the starting point for the Audi TT-RS motor, which
is special.