Why Porsche Gave the Taycan Enormous Brakes

Porsche's electric sport sedan has regenerative braking, but the car still has huge 16.5-inch rotors and ten-piston calipers up front. It all has to do with Porsche's braking torture test.

© Porsche   Porsche's electric sedan has regenerative braking, but the car still has huge 16.5-inch rotors and ten-piston calipers up front. It all has to do with Porsche's braking torture test.

By Chris Perkins, Road & Track

One of the most unique things about driving an electric vehicle is regenerative braking, where the electric motors that power the car help to slow it down, charging the car's battery in the process. Porsche engineers assume that drivers of the new Taycan electric sedan will accomplish around 90 percent of their braking via regen. 

So why does the Taycan have some of the largest friction brakes ever fitted to a road car?

The Taycan Turbo gets conventional steel brake rotors measuring 16.4 inches up front and 14.4 inches at the rear. Standard on the Turbo S, and optional on the Turbo, are carbon ceramic brakes, 16.5 inches up front, 16.1 inches in back. Both brake setups utilize giant 10-piston front and four-piston rear calipers. (The largest factory brakes in the world are the 17.7-inch front rotors available on the Bentley Bentayga.)

Big brakes are common on Porsche's high-performance models, and with up to 750 horsepower and a 2.6-second 0-60 sprint in Turbo S trim, the Taycan is certainly a performer. But there's a particularly interesting reason why Porsche fit the Taycan with especially gigantic brakes. 

A spokesperson told me that every Porsche is required to pass a braking torture test: 25 stops in a row, from 80 percent of a car's top speed down to 90 km/h (56 mph), with every fifth stop involving full ABS. For a car to pass, it has to generate between 0.8 and 0.9 g of deceleration every time. 

The Taycan presents a unique challenge. Its 161-mph top speed is relatively low compared to other Porsche products. And the EV boasts ultra-quick acceleration, so it doesn't take long at all to reach 80 percent of top speed, around 129 mph. This meant that, during Porsche's braking test, the Taycan didn't have much time at all for the brakes to cool between stops. 

Rather than change its braking performance standards for the Taycan, Porsche solved the problem by fitting those enormous brake rotors and ten-piston calipers. It seems a little funny given that, in normal daily driving, those giant brakes might almost never be activated, thanks to the car's regen capabilities. But the Taycan's brakes are critical to offering the performance Porsche demands—including the car's 7:42 Nürburgring lap time.