FILE PHOTO: A Tesla logo is seen in Los Angeles, California U.S. January 12, 2018. REUTERS/Lucy Nicholson/File Photo

(Reuters) - Tesla Inc, struggling with delay in delivery of its higher-priced Model S and X luxury cars, said on Tuesday it will bring back lower-priced options for those cars and roll out upgrades to improve their driving range and re-charging speed.

The company, striving to improve margins and post a profit later this year, has laid off workers including about half of the team hired to deliver cars in the United States, and said it would close stores to lower costs.

Tesla has since said it will keep higher-volume stores open, while announcing a 3 percent price increase on some models.

The upgrades include a new drivetrain design and a new adaptive suspension system, increasing each vehicle's driving range, the company said in a blog post here ahead of its first-quarter results on Wednesday.

With the upgrades, the long-range version of Model S and X can now travel 370 miles (595.5 km) and 325 miles, respectively, on the U.S. Environmental Protection Agency cycle.

The lower-priced options, or the ‘standard range’ versions, of Model X and Model S were available for purchase on Tesla’s website after Tuesday’s announcement for $83,000 and $78,000, respectively. Estimated delivery of both cars was set for May.

Earlier in April, Tesla reported fewer-than-expected vehicle deliveries in the first quarter, with figures for the Model S sedans and Model X SUVs more-than-halving compared with the preceding quarter.

The Silicon Valley carmaker has faced a range of challenges over the past year as one of the leaders in electric vehicle technology sought to ramp up production, deliveries and sales of the Model 3 sedan seen as crucial to its long-term profitability.