Large wheels look great on an electric car but what impacts do they have on a vehicle’s performance?
The honest, straightforward answer to whether it’s a bad idea to install custom wheels such as 20″ chrome rims like these on your EV is – probably yes, unless you are perfectly fine with sacrificing a noticeable amount of range and ride comfort for the sake of aesthetics (but there are of course some exceptions – more on this further in the topic).
While big rims might give your car a head-turning look, electric motors are pretty sensitive to wheel and tire changes, that’s why you need to be really cautious in choosing the new set of aftermarket wheels. Let’s dive in deeper into the topic and review the key disadvantages of swapping the stock rims with something fancy.
EVs rely heavily on aerodynamics to squeeze out maximum mileage, that’s why their stock wheels usually look a bit like flat dinner plates. There is a reason for that though – they are designed to slice through the air and avoid creating unnecessary swirl, whereas most aftermarket wheels have open-spoke designs that create turbulence, acting like little parachutes. This leads to the potential range loss of 10% to 15% just from bad aero.
Another problem is that some rims are pretty heavy because of the extra plating process (especially the chrome). When you combine that with a larger 20″ diameter, you are adding a lot of “unsprung mass” to the car. As a result, the electric motors have to work harder to spin those heavy wheels, draining your battery faster and slightly dulling the acceleration.
Just like on a regular gas car, fitting large rims in your wheel wells requires low-profile tires with thin sidewalls (think 30-35 profile) that provide much less cushioning against potholes, making it much easier to bend or crack them.
Besides, EVs are already incredibly heavy vehicles because of the battery pack installed at their base. That’s another reason why ride comfort can be compromised, making the car feel even more stiff.
This one is less obvious than the previous points, but the majority of stock EV tires are designed to be as quiet as possible because there is no engine to drown out their noise. Moving to a standard low-profile tire on a 20″ rim will make the cabin noticeably louder on the highway.
Just like on a gas car, to maintain the same driving manners of your car – the safest bet is to stick with aftermarket wheels that have the same size and weight parameters. This will allow you to preserve the range, acceleration, and hopefully reuse your stock tires (this alone can cut a significant sum).
Today there are lots of EVs that come with pretty huge 20-inch (or even 21-inch and 22-inch) wheels with shiny low-profile tires right from the factory. The Tesla Model Y, Ford Mustang Mach-E, Hyundai Ioniq 5, and Porsche Taycan are just a few examples that either come standard with or offer 20″ rims in top trim levels.
Here is a breakdown of popular EVs that come with 20″ rims (or larger) from the factory:
Tesla
Hyundai & Kia
Ford & Mustang
Luxury Brands
If your EV already comes with 20s, the situation changes dramatically, but installing aftermarket rims still comes with a few major catches. Unfortunately the aero penalty still applies. Even though the wheel size is the same, the design of the aftermarket wheels is usually drastically different. When automakers put 20″ wheels on an EV, they spend millions in wind tunnel testing just to make sure that the spokes are relatively closed-off or feature aerodynamic inserts to slice through the air (like Tesla’s Induction wheels).
Aftermarket chrome wheels almost always have open, flashy thin spoke designs. These act like air-brakes at highway speeds, creating unnecessary turbulence. Even if you decided to stick with the exact same 20″ tire size, you will likely still see a noticeable drop in highway range simply because you lost the aerodynamic efficiency.
Factory EV wheels, even the big 20″ ones, are usually forged or cast from lightweight aluminum alloys to keep the range and acceleration intact, which isn’t always the case with aftermarket wheel options. There are a few key techniques in the wheel manufacturing process that influence their weight and durability at a molecular level.
Cast Wheels: These are made by pouring molten aluminum into a mold. As the metal cools, tiny air pockets (porosity) can form, making the structure less dense. To make a cast wheel strong enough to support a heavy EV, manufacturers simply have to use more metal, making them appear bulky and heavy.
Forged Wheels: These rims start as a solid block of aluminum that is crushed under extreme pressure (thousands of tons), which “compacts” the grain structure of the metal and makes it much denser and stronger. Because the metal is stronger, you can use less of it – that’s why thin-spoke designs become possible.
“Flow Formed” (Middle Ground): In the essence these are cast wheels where the “barrel” of the rim is stretched and compressed using high-speed rollers, which makes it stronger and lighter than a standard cast wheel, but much cheaper than a fully forged one (though not as durable as the later).
A forged 20″ wheel can be 25-30% lighter than a cast 20″ wheel, which reduces “unsprung mass,” improves acceleration and helps reclaim some of the range lost to the 20″ size (if you came from the smaller size).
Also, because forged aluminum is denser, it is much more “malleable” (bends before it breaks). If you hit a massive pothole with a cast wheel, the brittle metal is more likely to crack or shatter, whereas hitting the same pothole with a forged wheel can result in a repairable bend.
Is it a “good idea” to get 20″ aftermarket chrome rims? It depends on your priorities. If you view your EV as a high-efficiency tool and you frequently drive long distances on the highway, oversized aftermarket rims are generally a bad idea because of the range loss. You would be better off with a polished forged Monoblock wheel, which gives you the chrome “shine” without the heavy weight and aerodynamic drag.
However, if your EV is a city commuter or a “style-first” vehicle, and you are comfortable losing a bit of range for a custom look, it is perfectly fine, especially if you choose a high-quality wheel. To get the best possible results, opt for flow-formed or forged rims to keep the weight as close to factory specs as possible.
