- Smaller 20-inch wheels improved the Ioniq 5 N’s highway efficiency by about 12%.
- The owner’s “nearly 100 extra miles” claim is an extrapolation, not a verified full-range result.
- Similar Tesla tests show smaller wheels can deliver meaningful EV efficiency and range gains.
Wheels and tires matter a lot for an EV’s efficiency. That’s why manufacturers give different range and efficiency ratings depending on the wheel size, because larger rims with grippy performance tires can rob dozens of miles of real-world range.
This means you can increase your vehicle’s range by equipping it with smaller wheels and more efficient, lower-rolling-resistance tires. Matt from the Downshift YouTube channel wanted to give his Hyundai Ioniq 5 N more range, because it only has an EPA-rated range of just 221 miles.
That’s a lot less than the non-N Ioniq 5 dual-motor all-wheel-drive with the same 84-kilowatt-hour battery pack, which gets an EPA rating of 290 miles. That’s 69 miles or around 24% less, and part of the reason for the difference is the N model’s 21-inch forged wheels wearing wide 275-section sticky Pirelli P Zero tires.
The first thing Matt did was change the rubber, opting for a set of Kumho Majesty 9 EV tires, which are designed for EVs with a low-rolling-resistance profile to boost efficiency. He then tested the efficiency on a 30-mile mixed-driving loop and found it increased from 3.3 miles/kWh to 3.6 miles/kWh with the Kumhos.
However, while these dedicated EV tires improved efficiency, they also dulled some of the sharp handling Matt bought the Ioniq 5 N for in the first place. So he went one step further, fitting custom 20-inch Demon Forged wheels with more performance-oriented Kumho Ecsta Sport all-season tires, and efficiency improved again.
On the same 30-mile loop, the Ioniq 5 N returned 3.7 mi/kWh, but he noticed a clear improvement while driving on the highway. At a steady 75 mph, the stock 21-inch setup had previously returned 2.5 mi/kWh, while the 20-inch wheels with the second set of Kumhos nudged that up to 2.8 mi/kWh over a 120-mile test. That’s a clear 12% improvement in highway efficiency.
Matt calculates that, with the 3.7-miles/kWh result for the 84-kWh battery, it could achieve a theoretical 310-mile range, which is nearly 90 miles higher than the EPA rating. However, the 310-mile figure isn’t the result of an actual range test from 100% down close to empty, and Matt acknowledges that his mixed-driving route tends to boost EV efficiency.
More importantly, his car could already average 3.3 mi/kWh on the same route, so the actual gain isn’t 90 miles. It’s the roughly 12% efficiency improvement measured between the stock and modified setups on the mixed-driving loop.
And the smaller the wheels, the greater the efficiency gains. Switching a 2020 Tesla Model 3 Performance from its factory 20-inch wheels to a set of 18-inch wheels reduced energy consumption by roughly 16% to 23%. Another test featuring two otherwise identical Tesla Model Ys found the one on 19-inch wheels to be around 7% more efficient than the car riding on 20s.