The invisible load on every journey
Aerodynamic drag depends on shape, frontal area, air density and the square of speed through the air.
Canvas of Knowledge · 14 November 2026 · Illustrated explainerThe useful equation
Drag force is one half × air density × drag coefficient × frontal area × speed squared. With other factors fixed, doubling speed multiplies drag force by four.
More than one number
A low drag coefficient does not by itself prove low total drag: frontal area matters too. Aerodynamic power is drag force multiplied by speed.
Different design missions
Xiaomi distinguishes its SU7 Ultra Prototype’s track-focused aerodynamic package from passenger-car priorities. Downforce, cooling and low drag can compete; a track prototype is not a production range claim.
THE IDEA TO KEEPCompare drag area and test conditions, not an isolated Cd headline.
Sources & further reading
- NASA Glenn · Drag equation →
- NASA Glenn · Drag coefficient →
- Xiaomi · SU7 Ultra Prototype aerodynamics →
Sources reviewed 14 November 2026. Specifications and availability depend on the product, market and date. Source organisations do not endorse this website.