i know stock size is 225 45 r17

235 45 r17's will fit, but i wanted to know if its recommended.

i called the audi dealership and they said i could mount them, but my spedometer would be off.

my car doesnt have quattro.

thanks!

 

Your speedometer will read about 1.5% slow. If you can live with that, and you are using your OEM A3 wheels, then there aren't any real other practical drawbacks.

 

why this happens and how we can get accurate readings.

 

Your speedo is calibrated at the wheels, counting each full rotation of the tire to equate it to distance travelled. For example, the OEM tire may take 873 rotations to travel 1 mile. if you change to a tire with a larger diameter, it will take less than 873 rotations to complete the same mile.

Since your OEM speedo was calibrated to the smaller diameter OEM tire, any larger diameter tire will result in your speedo reading too slow, and vice versa if the tire was smaller diamter than the OEM.

This will also throw off your odometer... which means you car will actually show less miles travelled than it really had!

The only way to fix this is to find a tire that has similar diameter as your OEM tires, as recalibrating the speedo sensors at the wheels will be expensive, and may also be illegal in some cases if it affects how the odometer counts distance travelled

 

You car's handling will suffer because the sidewall is a lot taller than your OEM 225/45R17 tires.

You car will also ride higher because the tire diameter is taller, and there will be less clearance between the top of the tire and the fender so it might rub.

Also, your OEM rims were not designed to use 235/45R17 tires so it will look very bulged so your wheel might look like a truck or van wheel...

There are some guys that use 235 wide tires but they would use a lower profile like 40 (235/40R17) but also a wider wheel to the sidewall (17x8 vs OEM 17x7.5)

The best is get the correct sized tires unless you are also changing the wheel to accomodate the wider tire.