EV Vehicle Range Simulator

Electric vehicles (EVs) are often marketed with an "EPA range," which typically refers to the vehicle's range at 55 mph. However, in practice, an EV's range decreases significantly as speed increases, primarily due to aerodynamic drag. This means that at typical highway speeds (around 75 mph), users will experience a noticeably shorter range than the advertised EPA figure.

This discrepancy led to the concept of an 'honest mile' for EVs, which represents a mile of range at energy use of 75 mph speed. For example, a Tesla Model X with an EPA range of 330 miles would have only about 245 'honest miles' of range. This alternative measure provides a more realistic expectation for drivers: they can expect "245 miles or more" rather than "330 miles or less" under typical highway conditions, more akin to gasoline car driver experience.

Another goal of this simulator was to explore what kind of EV would be needed to travel from San Francisco to Los Angeles (383 miles) at highway speeds (75 mph) on a single charge. Initially I thought that trying to optimize for vehicle weight and aerodynamics is the best way to achieve this. The simulation revealed that the most practical way is to have Tesla Model X equipped with a 170 kWh battery - adding 70kWh is would make it capable of accomplishing this feat.

This simulator allows you to experiment with various vehicle parameters and see how they affect range and energy consumption at different speeds, helping to understand the real-world performance of electric vehicles.

The simulator comes preloaded with data corresponding to Tesla Model X (to the best of my abilities).

Understanding the physics

This dashboard uses basic physics principles to calculate an electric vehicle's energy consumption. Here are the key equations:

1. Air Drag Force

This is the force of air resistance on the vehicle:

F_drag = 0.5 * Cx * A * ρ * v²

Where:

Cx: Drag coefficient
A: Frontal area (m²)
ρ (rho): Air density (typically 1.225 kg/m³)
v: Velocity (m/s)

2. Rolling Resistance Force

This is the force resisting the motion when the vehicle rolls on a surface:

F_rolling = Crr * m * g

Where:

Crr: Coefficient of rolling resistance
m: Mass of the vehicle (kg)
g: Acceleration due to gravity (9.81 m/s²)

3. Total Force

The total force the vehicle must overcome is the sum of air drag and rolling resistance:

F_total = F_drag + F_rolling

4. Power Required

The power required to overcome these forces:

P = F_total * v

5. Energy Consumption

Energy consumption per unit distance, accounting for drivetrain efficiency:

E = P / (v * η)

Where η (eta) is the drivetrain efficiency.

6. Range

The theoretical range of the vehicle:

Range = Battery Capacity / E