Yes, they do, because the sporty versions of the Honda Accord and Hyundai Sonata are equipped with firmer suspension components and wider, lower-profile tires than other versions. Tires may be a bigger factor in ride comfort than the slightly firmer suspension settings found on the Accord Sport and the Sonata's SE and turbocharged 2.0T models.
Before we launch into an explanation of the different tires available on these cars, we suggest you take the Tires 101 refresher course, here, for a comprehensive description of tire types and sizes and read Cars.com's advice on choosing the right tire, here.
The Accord Sport comes with 235/45R18 tires with a speed rating of V, meaning they can safely run at sustained speeds up to 149 mph. Although the Accord can't come close to that speed, the tires provide better grip in turns for sportier handling, but because they have narrow sidewalls (or a low-profile design), they also don't absorb bumps as well as an Accord LX. The LX rides on 205/65R16 tires with a speed rating of H (up to 130 mph). These tires are softer and have taller sidewalls that flex more over bumps. Accord EX and Touring models ride on V-rated 215/55R17 tires that are firmer than the LX's but not as firm as the Sport's.
The Sonata has a similar lineup. Base GLS models ride on H-rated 16-inch tires, the Limited has V-rated 17-inchers, and the SE and 2.0T models ride on low-profile, V-rated 18-inch tires.
Though we generally appreciate the better handling response that wider, low-profile tires provide, the loss in ride comfort at times is greater than the benefit. You should try different versions of the Accord and Sonata to see which you prefer, and we recommend you seek out the worst roads possible to test the differences. Smooth roads generally aren't much of a test.
Another factor to keep in mind: 18-inch tires will cost more to replace than 17- or 16-inchers, and low-profile designs often wear out faster.
- Side by Side: 2013 Honda Accord vs. 2013 Hyundai Sonata (Cars.com)
- Cars.com $26,000 Midsize Sedan Shootout: Overview (Cars.com)
- Expert Review: 2013 Honda Accord (Cars.com)
- Expert Review: 2013 Hyundai Sonata (Cars.com)
- Tires 101: What Your Tire's Markings Tell You (Cars.com)
- Getting the Right Tire (Cars.com)