Tesla Adding All-wheel Drive, Safety Features to New Version

Tesla Motors unveiled a faster, all-wheel-drive version of its Model S sedan Thursday along with some new safety features. The announcement put to rest a week of feverish speculation. Tesla CEO Elon Musk hinted about the news in a tweet last week. The Model S is currently a rear-wheel-drive car, which has hurt sales in snowier climates. Tesla is adding a second motor to power the front wheels. The all-wheel-drive version will have a top speed of 155 miles per hour, compared with 130 mph for the current version. It will also accelerate faster. Tesla hasn't yet said when the all-wheel-drive version will go on sale or how much more it will cost. The new safety features include automatic braking to avoid a collision.