What are the biggest rims you can put on your 1993 Honda civic?

The biggest rims you can put on a 1993 Honda Civic without any modifications are 15 inches in diameter. If you want to install anything larger, you'll likely have to do some minor fender rolling or pulling to make them fit correctly. Additionally, you'll want to ensure the tires you select have a profile height sufficient to fill out the wheel wells and provide adequate ride quality.