I'm considering buying a nearly new Audi Q5 S Line Plus which has 20-inch wheels as standard specification. When I test drove the car I thought that the ride was a little hard and asked about being able to swap the 20 wheels for the 19 or even 18-inch wheels that are standard on the lower specified models. These would be fitted to the 177PS 2.0 diesel.

When I asked the dealership about this they said that it is not possible as all the safety management equipment for steering, braking and suspension etc would be set up on the S Line Plus for 20-inch wheels and that fitting other size wheels will mean that all the safety management will not work correctly.

I can't see that this is right, as this engine in this car has three different wheel sizes and I can't imagine that when making the car on the production line different engine management modules are fitted to specific cars.

Can you please let me know if what I've been told is correct and I will have to have the 20-inch wheels as this might put me of buying the car?