taller & wider tyres will result in higher fuel consumption - Steering will be bit harder & suspension will deteriorate quick
PLUS - the error in actual speed & speedometer display. want to test !??? - goto motorway and observe your needle & the flash from Mtrway.Police ask for their cam reading OR
if you have a GPS - put it on Dash exposed to sky make a constant speed run for 5 km check your car speed & speed on GPS thats the error.