NHTSA complaint #11509792

Owner complaint summary

The brakes fail in wet conditions. Porsche Taycan has 2 brake systems- light braking is regenerative braking (converting mechanical energy into electricity) and for heavier braking the mechanical disc brakes take over IN THIS FAILURE SITUATION in wet conditions pressing the brake pedal does VERY LITTLE to slow the car. DURING THESE FAILURE SITUATIONS, there is 0 regenerative braking occurring. Normally if there is 0 regen braking mechanical brakes engage at 1% brake pedal press so the entirety of the brake pedal engages the mechanical brakes. DURING THIS FAILURE SITUATION, the mechanical braking system does not engage early so it does not begin to engage until near the end of the brake pedal travel. DURING THIS FAILURE EVENT, THE MECHANICAL BRAKES ARE ONLY AT MINIMAL STOPPING POWER (+/- 20%). It has been compared to the first stop after getting a car washed– one must ‘jam on’ their brakes in order to get their car to stop, after which it tends to stop well. Cars come from the car wash at 1-3 mph, so 10-20% braking power does not put the user in jeopardy. IN THESE FAILURE SITUATIONS THE PORSCHE TAYCAN only has 10-20% stopping power WHILE TRAVELLING ‘AT SPEED’ ON NORMAL ROADWAYS The first time this happened I was approaching a stop light in traffic. If the turn lane weren’t empty I WOULD HAVE CRASHED into the cars ahead of me; I jerked the car into the turn lane & eventually came to a stop, with the brake pedal pressed in at 100% for the entire time. It happens at speeds from 3-50 mph It HAS been reproduced with myself in the car by Porsche service, and by other people in their cars, it was reproduced on my car AND ALL OTHER TAYCANS ON THE LOT at the dealer – each car did it The dealer has done ‘everything in their power’ but it is still happening. I was told Porsche NA was investigating on their wet track at their Atlanta HQ, but that the cars ‘tested as designed’ No warning messages or errors –the regen braking gauge always shows 0% while this happens