A good Cd figure, signifying low wind resistance, is increasingly key to tackling any electric car’s Achilles’ heel: restricted touring range. VW says the ID.4, the brand’s first all-electric SUV, will have a Cd of 0.28 and a range of up to 310 miles (500km).
“The electric design evolution of the ID.4 means that we have focused very strongly on the aerodynamics,” VW Group’s head of design, Klaus Zyciora, tells us. “Its exterior design is clean, flowing and powerful with gentle, soft transitions alternating with sharp, clear separating edges. The design looks as if shaped by the wind itself.”
Key to the ID4’s low drag factor, says Zyciora, is its organically sculpted look and the way the car’s body is drawn in towards the rear. This first teaser drawing doesn’t show it, but at the back is a large roof spoiler to ensure the air flow is cleanly separated.
Zero point two-eight is good but it’s true to say Cd figures haven’t changed much over recent decades – the Audi 100 scored a 0.30 in 1982. The recent surge in sales of high-riding SUVs, with their much greater frontal areas, means true aerodynamic efficiency has likely decreased. The shift to pure electric power and need to maximise range is putting it back in the spotlight.