Tesla Motors Inc. is upgrading the slower-selling version of its Model S electric sedan, equipping it with a more capable battery, all-wheel drive and a bigger price tag.

The move comes as the Palo Alto, Calif.-based auto maker is racing to meet a steep sales target set for 2015 and down the road. Tesla said on Friday it sold a record 10,300 cars in the first quarter, but it needs to pick up the pace and average 15,000 vehicles a quarter to hit this year’s 55,000 goal.

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