Tesla Model S and Model X: Here’s how wheel size can affect efficiency

Wheels and tires can affect the efficiency of any car regardless of the powertrain, but since there’s already so much concern (most of it unnecessary) around electric car range, it might be worth to look into the actual measurable impact.

Some newly released documents about Tesla’s Model S and Model X to the EPA help us better understand the impact of Tesla’s wheel size options on the efficiency of those EVs.

Disclaimer: The results are based on limited tests that are not exactly representative of a normal driving cycle. It should be used more to represent the difference between options than the actual impact on efficiency. More in the Electrek’s Take further down.

The tests date back to December of last year, but they were recently released by the EPA and analyzed by Teslike on Tesla’s Subreddit to compare the energy consumption of 19″ and 21″ Model S wheels or 20″ and 22″ Model X wheels.

Here are the results:

• 4.9% more consumption for Model S P100D with 21″ vs 19″ wheels.
• 5.2% more consumption for Model S P90D with 21″ vs 19″ wheels.
• 11.6% more consumption for Model S 60/75 with 21″ vs 19″ wheels.
• 11.8% more consumption for Model S 60D/75D/90D with 21″ vs 19″ wheels.
• 22.2% more consumption for Model X P90D with 22″ vs 20″ wheels.
• 22.5% more consumption for Model X 60D/75D/90D with 22″ vs 20″ wheels.
• 23.3% more consumption for Model X P100D with 22″ vs 20″ wheels.

Electrek’s Take

As you can see, there’s quite a dramatic difference between the almost insignificant results for upgrading the Model S’ standard 19″ wheels to the sportier 21″ and the surprising 20+% of additional consumption for upgrading to 22″ wheels from the Model X’s standard 20″.

But it’s actually not as dramatic as it appears.

Some of the tests were performed on a dyno machine and at 50 mph (80 km/h). In real-world conditions and at higher highway speeds, other factors like wind resistance set in and reduce the importance of the rolling resistance, which is what is accounted for in those tests.

Nonetheless, there’s a clear and small impact on efficiency that you might want to take into account.

Tesla used to disclose the actual overall possible impact on range, which it put at “10-15% (hat tip to Teslike agian):

Featured Image: Tesla adds new aftermarket 20″ ‘Helix’ wheels for the Model X