Can you compare 18" vs. 19" tires?

19’s will give you better handling due to lower profile. However the ride will suffer, tire life will be shorter, and cost more money. Just stick with the stock units as that is what it is designed for.

Answers not posting.

We race SRO GT4, currently in an Aston Martin Vantage, but up to a few months ago we ran an Audi R8..... The car you propose is one of my favorites, and it's actually underpriced compared to its competition, if there actually is any. The package with the 18" wheels is a very good effort on Audi's part for the average driver. The packages with the 19" rims are set up to be more sporty throughout. You'll get a rougher ride, but you can adjust suspension to counter that if you wish.... I hope you buy one that suits your driving habits & style. Then post your own review here in six months..... I'm kinda jealous.

There will be negligible differences. But in general the larger the diameter, the less side wall, so less comfort, but better handling in corners. Of course larger diameter tires cost more and you will need to buy rims as well. Type of tire will also contribute to the handling and feel. Be it a different between all season or summer tire and even different manufacturers.

You've found one of my favorite cars. The standard version with 18" wheels is made for everyday Audi drivers; you know, them. The packages with 19" rims are more sporty, and if that's how you drive, choose one that drives as you like to. To me, it's really worth the added cost.