PALO ALTO (CBS SF) — More than half of Tesla’s Model S drivetrains may need to be replaced before the electric cars cover 100,000 miles, a new report revealed.

Data analyzed by Plug-In America showed that out of 327 Model S cars, that as many as two-thirds of those cars’ drivetrains had to be replaced within 60,000 miles, Green Car Reports reported.

In fairness to Tesla, it’s not that the drivetrains are failing.  The company replaces drivetrains before they fail, when they start making noise.

In October, Consumer Reports raised questions about reliability issues with the Model S sedans.