At Aptera, efficiency isn’t just a goal—it’s the foundation of everything we do. From our ultra-lightweight composite body to our aerodynamic teardrop shape, every design decision is made to maximize range and minimize energy consumption with the goal of making every journey powered by the sun. One of the most effective ways to measure a vehicle’s efficiency is coastdown testing, a process used across the automotive industry to assess aerodynamic drag and rolling resistance.
Recently, we took our first production-intent validation vehicle to the proving grounds for coastdown testing—and the results left us in awe. Aptera took over three minutes to decelerate from 60 mph to a complete stop, showcasing just how little resistance it faces as it glides through the air. Accounting for slope, Aptera’s coastdown was two miles long. Based on our calculations, Aptera’s coastdown distance is significantly more than any other vehicle on the road today — gas or electric! This is just a tiny glimpse of Aptera’s extreme efficiency—and it’s only going to get better.
What is Coastdown Testing, and Why Does It Matter?
Coastdown testing is a widely used industry method for evaluating how efficiently a vehicle moves through the air and along the road. The test involves accelerating to a set speed (in this case, 60 mph), cutting power, and measuring how long the vehicle takes to come to a complete stop. The longer a vehicle coasts, the less energy it needs to maintain speed—indicating lower aerodynamic drag and rolling resistance.
By allowing a vehicle to roll to a stop without power, engineers can isolate aerodynamic drag, rolling resistance, and powertrain mechanical resistance, key factors that impact energy consumption and real-world driving range. For Aptera, this test is helping our engineers fine-tune everything from gear selection to aerodynamics and prove what they’ve designed in computer simulations translates into real-world performance.
How Aptera’s Coastdown Compares
While coastdown times vary by vehicle type, most modern sedans come to a stop much faster due to their higher aerodynamic drag and rolling resistance. Aptera’s ultra-streamlined shape and lightweight build give it an exceptionally long coastdown time, reinforcing our belief that this is the most efficient passenger vehicle ever designed.
Even more impressively, our coastdown test exceeded the measurement limits of standard equipment—a sign that we’re pushing the boundaries of what’s possible. To gather even more precise data, we plan to re-run the test on a long-distance oval track, allowing us to measure performance in both directions to account for external factors like wind.
Watch Aptera’s Coastdown Test in Action
What This Means for Aptera’s Efficiency Goals
One of our biggest targets is achieving an industry-record 100 Wh/mile energy consumption, making solar mobility possible in ways never before seen in passenger vehicles. This coastdown test proves we are well on our way to meeting that goal.
With an ultra-low drag coefficient, reduced rolling resistance, and optimized powertrain efficiency, Aptera is set to deliver:
- More miles per charge than almost any other electric vehicle on the road today
- Solar-powered driving that minimizes reliance on charging
- Lower energy costs for drivers
What’s Next?
As we continue validation testing, we’ll be fine-tuning every aspect of Aptera and sharing the results along the way. Next steps include:
- Completion of our second validation vehicle with further refinements
- Extended highway drive cycle testing
- Aerodynamic tuft testing to visualize airflow over the vehicle
- Solar output testing
With each test, we move closer to the start of production of the solar electric vehicle we’ve all been dreaming of. We can’t wait to share more as we hit new milestones—stay tuned!
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