Biggest i can get under the car is a 33x15x15 Goodyear 2078 stiff sidewall. Those tires have a section wideth of 17.8, and are within 1/2 inch each side. I recomend doing your best to leave a little extra room as they are a beach to get iff the car. I have to deflate the tires and wrestle with them to clear the outer fender.