Aptera and 1000 Mile Range
Why the drag coefficient is vital to long range.
Range, range, range. The goal of most manufacturers is to make an EV with the longest range. Well, that bar has been raised. Aptera announced a futuristic-looking 3-wheeler that has long range, but more importantly exceptional efficiency.
The method of achieving this milestone is clear. Engineers and designers at Aptera designed the vehicle solely around achieving the lowest possible drag coefficient. A low DC would theoretically lead to a vehicle that could be made with a smaller battery and lower weight, in turn resulting in increased range.
What is Drag Coefficient?
The Drag Coefficient can be defined as follows
Where Fd is the drag force, “p” (rho) is the density of the air, “u” is the flow speed of the object relative to the fluid, and A is the reference area. In this particular case the reference area is the front of the vehicle that is working to push through the air.
Over the decades drastic design changes have resulted in exponential impacts on the drag coefficient. Lower drag has significantly contributed to features such as sleek styling and improved fuel economy. Fuel efficiency of vehicles in the 1920s was roughly 14 miles per gallon, while today’s vehicles achieve roughly 25 miles per gallon due in large part to improved aerodynamics.
Below is a simple graphic of the forces in play when driving a vehicle down a road. The vehicle faces pressure from the air as it tries to move forward. The engine and tires constantly battle the air when trying to accelerate, and is the reason why you must constantly have your foot on the gas pedal to maintain speed.
With this in mind, I have included a table below listing some popular vehicle models and their corresponding drag coefficients. Size and shape of the front end of the vehicle appear to directly correlate which makes intuitive sense.
Aptera’s proposed battery size is 100kWh with a range of 1000 miles (10miles/kWh). The Tesla Model 3 Long Range has a battery size of 75kWh with a range of 353 miles and efficiency of 4.71 miles/kWh, which makes Aptera over twice as efficient as the industry leader.
Let’s also take into account that the weight of the Model 3 Long Range is 4031 pounds of which 1060 pounds is the battery. Aptera could theoretically make a 353 mile range vehicle with a battery that weighs just 375 pounds (~64% less than the Model 3 battery).
Smaller battery and less weight. What could Aptera possibly do? Exactly what you see. They are redefining the vehicle and even have plans to incorporate solar panels on the roof of the car, further reducing the need to charge the vehicle.
Aptera is striving for more than just longer range, they are claiming the potential of “Never Charge”. Innovation in 2021 is already off to a fast start.
References:
https://www.aptera.us/ - Aptera Home Website
https://electrek.co/2020/12/07/aptera-super-efficient-electric-car-1000-miles-range-solar-power/ - Electrek Report
Aptera Launch Video