Really if you want to get scientific about it the only thing that will happen is a slight change in gas mileage but other that nothing.
RE: Can I fit different size tyres/tires than the factory originals ? I have a 2004 Audi Avant (Estate) the tyres that are currently fitted are 205/55/R16 91 W. I have been offered some tyres at a bargain price but they are slightly different 205/50/R16 87 W. I telephoned an Audi main dealer and they said they would not recommend this because of the speed rating.
That depends on the year, make and model of vehicle, OEM tire size and the replacement tire size you plan to use, none of which you have provided.
