Tesla Motors: Is It Time to Sell My First Double-Bagger?

Tesla Motors (NASDAQ: TSLA  ) reported first-quarter earnings last week, blowing away expectations and sending shares soaring. Less than four months after I first invested in this electric-car company, my shares have doubled. I'm a long-term investor, but a surge like this might be cause for concern. Should I take the Steve Miller Band's advice and "take the money and run"? Or should I listen to the Steve Miller Band and let Tesla shares "keep on a-rockin' me, baby"? Let's take a look.

Go on, take the money and run
Tesla bears have plenty to chew on. Before this quarter, the start-up automaker had never reported a quarterly profit, and many saw Tesla as little more than billionaire founder and CEO Elon Musk's latest pet project. With the connections and finances to get his company started, naysayers believed that this company's full-throttled idealism would soon have it sucking on financial fumes.

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Even for those investors who believe in the future of the electric car, Tesla is hardly a stable or safe investment. Toyota Motors (NYSE: TM  ) made hybrid history with its Prius model and raked in $225.8 billion in revenue for fiscal 2012. That's 546 times larger  than Tesla's $413 million in sales.

There's even speculation as to whether electric cars have already had their heyday. With fuel efficiency at all-time highs, who needs electric when gas goes further? In China, Ford's (NYSE: F  ) 31 mpg Focus is the best-selling vehicle, and April sales up are up 41% compared with the same month last year.

Even if Americans hang on to their hemis, Ford's and General Motors' (NYSE: GM  ) new pickups pack more punch for less petroleum. GM's Chevy Silverado offers the most fuel-efficient V-8 engine to date, offering 23 mpg to would-be gas guzzlers.

Keep on a-rocking me, baby
But Tesla shares are up for a reason, and bulls are revving their investor engines louder than ever before.

If I thought Tesla was a direct competitor with the likes of Toyota or Ford, I'd tuck my tail between my legs and cash out today. The Blue Oval and its Japanese counterpart may be less agile than Tesla, but monster trucks don't need to aim when they crush ants beneath their wheels.

In reality, Toyota is actually a Tesla investor itself, and the two companies have massive consumer credibility to gain from double-teaming the efficiency advantage. Tesla poured 66% of its 2012 sales straight into R&D, paving the way for partnership potential in the years to come.

This quarter specifically, investors were elated to see Tesla turn a profit. At $15 million net profit, or $0.12 adjusted EPS, this growth stock is hardly a balanced book. Nevertheless, seeing green instead of red is always a plus for any serious growth stock. For me, I place more importance on the automakers' seasonally adjusted 83% increase in sales than its positive net income. In the words of Field of Dreams' Shoeless Joe Jackson, "If you build it, they will come."

As a final tip of the hat to Tesla's potential, Consumer Reports released a May 9 statement declaring its Model S the best car -- ever. With a score of 99 out of 100, the publication hinted at the future of vehicles when it stated that the Model S outrated all other vehicles "even though it's an electric car. In fact, it does so because it is electric."

Sell in May? I don't think so.
"Sold too soon" is a common sob story among investors, and I'm not going to let Tesla be one for me. Valuation is nearly impossible for a company with the growth potential of Tesla, and I'm sticking to my long-term investing rules when it comes to this stock. Barring an event of epic proportions (and a good quarter doesn't qualify), I hold on to my investments for a minimum two-year period, for better or for worse.

Tesla's stock may tumble in Q2 -- or it may soar. Regardless, I'm in it to win it and believe that Tesla has what it takes to keep electrifying my own earnings for years to come.

But don't just take my word for it. The Motley Fool has assembled the most in-depth Tesla research available for smart investors like you. Thousands have already claimed their own premium ticker coverage, and you can gain instant access to your own by clicking here now.