Tesla Motors (NASDAQ:TSLA) rewarded shareholders in 2014, with its stock price climbing more than 27% from around $150 a share in early January 2014 to where it trades today, around $191 a pop. For those keeping score at home, that compares to a rise of just 12% in the S&P 500 over the same period. Nevertheless, 2015 could be an even bigger year for Tesla's stock thanks to three key catalysts, including the rollout of new higher-margin EVs. Here are three reasons investors should love Tesla Motors in the year ahead.

1. New leasing program
Tesla is making it easier for people to buy its all-electric cars. The EV maker introduced a lower-cost lease option in October that reduces the monthly cost of owning a leased Model S by as much as 25% -- thus creating a more compelling value proposition for consumers. Tesla was able to pull this off by partnering with U.S. Bank, which operates at a much lower cost of capital than the California-based carmaker.

Under the new leasing terms, you can now lease a Model S for between $777 and $1,271 per month. This should fuel both U.S. demand and earnings growth in the quarters ahead. Moreover, Tesla now expects to lease about 3,000 to 3,500 Model S cars in North America during the fourth quarter.

2. International expansion
Tesla's stock took a hit earlier this week after the company's chief executive, Elon Musk, said that sales of its vehicles in China were weaker than expected in the current quarter. However, "China is a small percentage of our sales right now," Musk told Bloomberg. Nonetheless, Tesla's recently opened Shenzhen location in China is one of the company's highest-grossing stores worldwide today.

It's also important to remember that it has been less than a year since Tesla first entered the Chinese market. After all, building out a reliable charging infrastructure and convincing drivers to buy your gas-free cars in a new market takes time.

Tesla's Supercharger Network in China. Source: Tesla Motors. 

Despite near-term challenges, China should be a massive market for Tesla over the long haul. In addition to installing its Supercharger stations across Asia, the EV maker has also gained the support of the Chinese government. Tesla drivers in China, for example, are entitled to free license plates in Shanghai, thereby sidestepping the usual auction price of $10,000 to $15,000 per plate. This should help incentivize more Chinese consumers to buy Tesla's zero-emissions vehicles. What's more, China is just one piece of the company's much larger global expansion strategy.

Tesla Motors now sells its gas-free cars in 15 countries including Canada, Norway, Austria, and the U.K., to name a few. International expansion will be an important theme for Tesla in 2015 as it continues to expand its presence in key markets such as Hong Kong, Japan, and more recently, Australia. As Tesla's cars begin to gain traction in new markets around the world, it should significantly accelerate revenue growth for the company.

3. Higher-margin cars
Tesla entered the new year with overwhelming demand for its new higher-margin version of the Model S. The company introduced the world's first dual-electric-motor car in late 2014 to great fanfare. In fact, Musk told GQ magazine, "Demand for the P85D is off the charts." As a result, the company now expects that more than 70% of the cars it produces in 2015 will be dual-motor. This should boost margins for Tesla going forward.

Perhaps the most compelling feature of Tesla's new P85D Model S is its ability to go from zero to 60 mph in just 3.2 seconds. This dual-motor version, therefore, does more than lift margins for the automaker; it also proves that an electric car can beat gas-powered luxury cars on both efficiency and performance. This will likely be a catalyst for Tesla when it begins to ramp up deliveries of its dual-motor EVs in February 2015.

Foolish takeaway
Tesla's stock is currently trading in the middle of its 52-week range. The stock nose-dived last week due to near-term worries over weak sales in China as well as fear that cheap oil prices will hurt demand for electric cars in 2015. However, this is a very shortsighted view. With shares of Tesla now trading more than 36% below the stock's high of $291.42, I believe this creates an opportunity for long-term investors to buy Tesla stock and hold it for the next three to five years.