I have a problem with my ibiza 1.6 mpi engine 110 hp. I can't exceed 150 km/h but in inclined roads i hardly reach it 170 km/h with a cut in engine what do think the problem is due to although the computer shows everything is ok.
The technical specs for your vehicle are listed here:
They list a MAXIMUM speed of 187 km/hr. So your 170 km/hr is close enough to that figure that I suspect there is nothing wrong. The 187 figure was likely obtained under controlled conditions at a track where you are running on a public road with varying conditions.
This is not exactly a "performance" vehicle as the 105 HP listed is quite low for a vehicle that weighs more than 1000 kg.