The range of an electric vehicle varies based on numerous factors. Among these, aerodynamics, wheel design, the presence of a heat pump, motor type, and drivetrain configuration all play major roles in determining how far your EV can travel on a single charge. Let’s dive into these technical aspects that directly impact your electric driving experience.
No matter how robust charging networks become across the United States, range remains the battleground of electric vehicles, alongside price. An EV might excel in handling or interior quality, but without sufficient range (roughly 250 miles to satisfy most American drivers today) and a reasonable price tag, its market success is at risk.
Such vehicles aren’t rare in today’s market. Take the Mazda MX-30 – an interesting car in many ways, but falling short on both price and range metrics. Similarly, the Lexus UX300e offers adequate range but comes with a price point that makes it difficult to compete effectively.
While price variables are numerous, range factors are more defined. Battery capacity obviously plays a dominant role, but several technical elements directly affect range without relating to the battery itself.
The factors we’ll examine in this article are determining parameters that allow an electric vehicle to consume less energy and, as a result, achieve better range. Unlike gas-powered vehicles, EVs involve some new variables worth understanding.
Aerodynamics – the most significant factor?
We won’t detail all aspects of aerodynamics here, but let’s clarify the importance of the drag coefficient (Cd) on an EV’s efficiency. Actually, we should focus on the CdA value, a figure rarely provided by manufacturers but which accounts for more parameters than the Cd alone.
While related, the CdA is the drag coefficient multiplied by the frontal area exposed to air in square feet. This allows for meaningful comparison between models, unlike the Cd alone. Simply put, Cd refers to the car’s shape viewed from the side, while CdA refers to the entire surface area of the car that contacts air. The lower this value, the better.
According to engineers, aerodynamics matters more than weight, meaning a heavy but aerodynamic car is preferable to a lightweight but boxy one. This applies to both electric and gas-powered vehicles.
The only somewhat positive aspect of a heavy vehicle (and it’s barely a positive) is that weight creates momentum, which is good for regeneration – heavier cars generate more kinetic energy during braking.
On highways, a heavy but well-designed car like the Tesla Model S might consume the same or even less energy than a small electric SUV that’s 1,100 pounds lighter (like an electric Jeep Avenger). At low speeds, it’s a different story, as aerodynamics has less impact than weight below 45 mph.
For an electric car, a good Cd (and more importantly, CdA) often translates to impressive range relative to battery capacity and segment. Among the best performers in this category, excluding concept cars and ultra-niche vehicles, are the Mercedes EQS with a Cd of 0.20 (CdA of 0.50), the Tesla Model S just behind at 0.208 (CdA of 0.48), and the Hyundai Ioniq 6 with a Cd of 0.21 (CdA of 0.46).
Wheels and tires – gaining precious miles
When discussing running gear, tires play a significant role – and wider tires mean more energy lost. With vehicles growing larger, tires logically grow wider too. Wider tires improve handling and road grip, and who wants a heavy electric car with uncertain dynamic behavior?
Manufacturers must equip their models with wide tires, but beyond a certain width, range suffers. Wider tires create more friction, wasting energy. Tire makers try to compensate with low rolling resistance compounds, but this usually isn’t enough. Engineers typically agree that problems start at widths exceeding 9 inches (230 mm). On some vehicles, like the base model BMW i4 eDrive35, width already reaches 10 inches (255 mm).
Regarding wheels, their impact is less significant than tire choice, but oddly, we tend to pay more attention to them. Why? Because they’re visible! The common wisdom states that uglier wheels tend to be more efficient. The accurate formula would be: “the more enclosed the wheel design, the more efficient it is.”
How much can wheels affect an electric car’s range? Wheels create a fan-like effect when rotating, projecting air sideways and disrupting aerodynamic flow.
A quick look at Tesla’s configurator clearly shows the range impact of different wheel choices according to official EPA ratings. On a previous generation Tesla Model Y, the standard 19-inch “Gemini” wheels allow the car to claim 283 miles of range.
Switching to the optional “Induction” 20-inch wheels (a $2,000 upgrade) reduces range by 15 miles in exchange for aesthetic appeal – these wheels may be less aerodynamic, but they’re decidedly more attractive. Overall, wheel choice can modify range by 5% to 10% in some cases.
Motor type matters too
This is probably one of the least considered factors when discussing electric vehicle efficiency. As you may know, there are several types of electric motors.
To put it simply, permanent magnet motors – the majority found in today’s hybrid and electric vehicles – are the most efficient.
Permanent magnet motors are valued for their energy efficiency, compact size, and low maintenance. They offer several advantages, starting with efficiency. By eliminating losses associated with rotor windings, these motors typically outperform induction motors in energy efficiency. In other words, they consume much less electricity, enhancing electric vehicle range.
That said, induction motors can perform just as well as permanent magnet motors. This type of electric motor is widely used in various industrial and domestic applications, though less so in automotive settings, even though Tesla uses them for its Dual Motor models. It operates on the principle of electromagnetic induction.
Asynchronous motors are robust, reliable, and cost-effective, but their efficiency isn’t optimal, typically maxing out around 80%, although Tesla has achieved 88% at high speeds through various technical solutions. Still, Tesla is gradually moving away from these motors toward variable reluctance motors, a relatively new technology in the automotive industry, currently used by Tesla and Toyota. It often powers precision machinery. Its efficiency is excellent, reaching up to 95% – the best for an electric motor!
For comparison, a gas engine’s efficiency hovers around 40% in the best cases. This means 60% of the energy used (fuel) is converted to heat. That’s largely why gas engines run hotter than electric motors.
Thermal management – a factor to consider
If you own an electric car, you likely know how much temperature affects your vehicle’s range and charging time at stations.
Motor size matters because a larger surface area allows heat to dissipate more effectively. Tesla uses high-power motors for this reason. However, these motors can drain the battery faster at full load. This might seem counterintuitive, but it’s what we observe in real-world testing.
Motor cooling, combining ventilation and liquid cooling, is vital for efficiency. Similarly, batteries require a minimum temperature to maintain efficiency. A cold battery holds less energy than a warm one. Warming the battery consumes energy, which explains why consumption increases in winter (along with the fact that heating draws more power than air conditioning).
A heat pump benefits range by heating or cooling various components to maximize efficiency. Battery cell architecture also matters – square pouches are harder to cool than batteries made of small cylindrical cells.
Electric cars with air cooling (like the VW e-UP!) may struggle with temperature management, leading to overheating or charging issues, especially in cold weather. This cooling method has been largely abandoned in recent years, though Nissan held out with the Leaf. The drawbacks are evident – charging speed can decrease after successive charges as the battery pack heats up, triggering safety protocols that limit performance.
All-wheel drive for lower consumption?
In gas-powered cars, all-wheel drive typically means better traction and performance for certain sports models. For electric vehicles, this is also true, but sometimes it can reduce energy consumption. How can adding weight – specifically an electric motor on one of the axles – reduce consumption?
With all-wheel drive in an electric vehicle, there’s greater capacity to regenerate energy during braking and deceleration with two motors. Remember that both motors also act as generators when you lift off the accelerator, allowing for even more energy recovery.
There’s another, more technical argument. Each motor has its own differential since they’re on different axles. This allows engineers to control the gear ratios independently. The car’s electronics can select either motor at predetermined speeds.
For example, if the rear motor has gearing that favors efficiency, it will be prioritized at higher speeds. Tesla goes even further by using two different types of electric motors in a single vehicle – an asynchronous motor on one axle and a permanent magnet motor on the other.
Keep in mind, though, that in most cases, a single-motor electric vehicle will consume less energy.
(Have you noticed how carefully EV designers balance all these factors? It’s almost like solving a puzzle where changing one piece affects all the others.)
What’s your take on electric vehicles? Are you ready to make the switch, or are you waiting for ranges to improve even further?
