So I Just Got The Update And Changed My Rivian R1S's Tire Size From The Settings Screen, And Man, My Range Estimate Went From 320 To 273 Miles

Rivian owner Mike Andrews recently got the over-the-air update but decided to change his tire size from the settings screen. Unfortunately, this caused the range estimate to go from 320 to 273 miles. This introduces a little-known fact about things that affect range. Apparently, the tire you get will directly affect efficiency as to how far the electric vehicle can go on a single charge.

According to Mike’s post, “So I just got the update and changed my tire size from the settings screen. Man, my range estimate went from 320 to 273 miles. I knew getting 275/65R20 would cause a range loss, but I was not expecting that much. Wheels and tires are supposed to be lighter than stock 21s, so I wonder how accurate the computer is. Also, Toyo tires weren’t an option. It was either going to be stock Pirelli AT tires or Goodyear. Is anyone riding the Toyo AT3 EV tire? What kind of range are you getting for a Quad motor large pack?”

Various commenters chimed in on the best way to mitigate the reduced range. David K Liu suggested checking tire pressure to make sure it is set correctly based on the new tire size. Others like Brian Au and Jim Hollingsworth on the thread indicated that 273 miles was the default so there was nothing wrong with the range estimate. Rivian does confirm that it is between 270 and 410 miles on a single charge, so Mike may have legitimate concerns linked to the chosen tire.

The Science Behind Tires and EV Range

Tires typically affect the range in different ways depending on their weight, tread patterns, rolling resistance, or aerodynamics. Tire weight adds to the vehicle's mass and affects the energy required for both acceleration and deceleration. A heavier tire may increase the unsprung weight and consume more energy, reducing the range. Mike’s initial setting for the all-terrain tires may have been better for off-roading, but this caused the range to decrease by 15%.

Rolling resistance is also a significant factor affecting not only electric but gas powered vehicles as well due to the strain on the drivetrain and suspension. Low-rolling resistance tires are generally designed to reduce energy loss because of minimal friction between the tire and the road. Traditional gas-powered vehicles, though, may compensate for higher rolling resistance by going through more fuel. The same applies to electric vehicles, which have a limited battery capacity. That leads to a lower-than-expected range of 10 to 15%. It is also worth noting that Mike's tires, which were 275/65R20s, generally have a higher rolling resistance than the stock options.

The reason is they are larger and often designed for off-roading. That means they have deeper tread patterns, which are meant for grip. Similarly, their large size increases the contact part with the road, contributing to bigger energy consumption. Tread pattern also plays a role in ascertaining rolling resistance and energy efficiency. The tires designed for all-terrain use have deeper grooves, which are meant to offer better traction on harsh ground. However, these attributes also increase the friction level between the tire and the road, making the vehicle work harder to move. Stock tires made for the highway or touring, though, have shallower treads. These make for smoother rolling and less drag, so they would have helped the Rivian maintain optimal range.

Choosing the Right Tires

Electric vehicle owners may consider low-rolling-resistance tires to ensure the right balance between performance and efficiency. Pirelli Scorpion Verde All Season tires would be a good alternative, considering Mike’s preference for Pirellis. These have a high silica compound to reduce energy consumption and optimized tread patterns to lower rolling resistance. The 27555R21 was also made specifically for Rivian models.

There was a question about Toto Open Country A/T IIIs, which are all-terrain tires. These do have exceptional traction and durability, but they are high-rolling-resistance types due to the deep thread patterns, so they would not help the range estimate. Other owners with this problem should also go for stock tires rather than the aftermarket options. Manufacturers tend to equip their vehicles with tires that are optimized for efficiency. While these tires might improve specific driving attributes, they typically sacrifice the range in favor of performance.

Maximizing EV Range via Tire Maintenance

Aside from choosing the right tire, EV owners need to maintain their vehicles to ensure efficiency. This can be done by regularly checking tire pressure. Under-inflated tires tend to increase rolling resistance and reduce range by 3 to 5%. Similarly, Rivian owners may consider using aluminum or forged wheels because these are lighter and increase efficiency. Tires should also be rotated regularly because uneven wear can lead to higher resistance.

While commenters may have been skeptical about the ability of the R1S to reach 320 miles of range, the choice of tire is a significant factor affecting efficiency. The wrong choice can reduce overall range by 10 to 15% as was witnessed in this case. Owners should also factor in their driving behavior as part of the reason behind range estimates. Aggressive braking or sudden acceleration increase energy consumption, affecting the range. A steady driving style will increase tire longevity and overall efficiency.

Image source: RIVIAN Electric Vehicles Discussion, Referenced Above.

Nicholas Muhoro is an automotive journalist covering car news and has a decade of experience sharing working at HotCars and TopSpeed. You can follow Nicholas on X and on LinkedIn to stay in touch and follow his news coverage at Torque News.