Tesla Motors Inc. TSLA, +1.63% said Thursday it delivered a record 11,507 Model S vehicles in the second quarter, up 52% from the year-earlier period. The number was well above the company's estimate of 10,000 to 11,000 units, sending its shares up almost 3% in premarket trade. The electric car maker headed by entrepreneur Elon Musk has started reporting quarterly sales with the target of publishing them three days after the end of the quarter. That date would fall on Friday, but markets are closed that day in observance of the July 4 holiday. Shares have gained 21% in the year so far, while the S&P 500 has climbed just 0.9%.