Car tires, wheels grow in size in latest trend

Eighth-generation Sonata (DN8) model [Courtesy of Hyundai Motor]

The latest trend in the automotive market is larger wheels and tires, thanks to evolving fuel-efficiency technologies and the growing adoption of electric vehicles. Eighteen-inch tires, once considered exclusive to premium cars, are now commonly used in entry-level models. Standards for high-inch tires are increasing to 19 inches or even 20 inches, following the trend among new releases to fit larger wheels.

According to industry sources on Thursday, Hyundai Motor Co.’s eighth-generation Sonata (DN8) model, a medium-sized sedan, comes equipped with 17- or 18-inch tires as a standard. These tire sizes are similar to those fitted in the large Hyundai sedan, the Equus, often dubbed as the predecessor of the recent Genesis G90 model.

The second-generation Equus, released in 2009 and discontinued in 2015, came with 17 to 19-inch tires while the sixth-generation Sonata (YF), available in the market during the same period, came with 16-inch tires. In terms of wheel and tire size alone, the Sonata has caught up with the Equus, once synonymous with luxury cars, after a decade.

Larger wheels and tires enable better cornering and braking performance, but they also reduce fuel efficiency because larger wheels add more weight and increase resistance, or aerodynamic drag, when tires rotate on the road surface, resulting in higher air resistance. For example, when 17-inch tires are fitted to the eighth-generation Sonata gasoline 1.6 turbo engine model, the certified combined fuel efficiency is 13.5 kilometers per liter, whereas it decreases to 13 kilometers per liter when 18-inch tires are used.

Automakers, however, have been able to achieve even better fuel efficiency in their new models compared to previous models after adopting larger wheels and tires. The certified combined fuel efficiency of the eighth-generation Sonata with 18-inch tires surpasses that of the sixth-generation Sonata with 16-inch tires, which is 12.8 kilometers per liter. The recently launched new Santa Fe, equipped with 20-inch tires, achieves a certified combined fuel efficiency of 10 kilometers per liter, surpassing the fuel efficiency of the previous generation model with 18-inch tires, which was 9.5 kilometers per liter. The Santa Fe’s fuel efficiency was assessed based on the seven-seater, gasoline 2.5 turbo two-wheel-drive model.

Another contributor to the trend of adopting larger wheels and tires is believed to be the preference for sports utility vehicles (SUVs) and the growing sizes of new releases. In the domestic market, the proportion of SUVs in new car sales increased to 54 percent in 2021 from 46 percent in 2019. SUV sales have topped 60 percent in 2023 to date.