I have an Audi A6 with 245/45/R18 tires. My tire company, Discount Tire says the are several optional tire sizes that can be used on the same wheels. I am considering two optional sizes because the same tire is $60 to 70 cheaper than a 245/45/R18. The two sizes are 225/45/R18 and 235/50/R18. What are the negatives of using one of these optional sizes?

 

If you live where there is a lot of snow, the narrower tire will provide a little more traction. Otherwise what you save up front may be lost by having less rubber between you and the road and the tires wearing more quickly. Keep in mind this is a heavy car and Audi recommends the stock size tire for a reason. By the way, I found Continentals worked best on my Audi even though I got slightly better mileage from the oem Pirellis.