Tesla Motors "founder" Elon Musk has a propensity for boasting about his electric car business, but the company's latest SEC filing shares the risks he doesn't like to talk about, including having the Roadster's advertised range cut 30%.

Musk, now the CEO of a publicly traded company, has turned doubt about Tesla's viability into a badge of honor, telling critics earlier this month: "Accept the possibility that every now and again there's going to be an exception to the rule. In this case, it's Tesla."

Since Tesla went public in June, raising $226 million, it now has to provide investors with a detailed look inside its business roughly every three months, via filings to the U.S. Securities and Exchange Commission. The most recent one arrived late Friday, with 30,000 words about ways Tesla could stumble or collapse. We've distilled them down to 10 big hurdles:

1. Tesla's best guess at how the Environmental Protection Agency will set mileage rules for electric vehicles might reduce the Roadster's touted 245-mile range and its 300-mile promise for the Model S sedan by "up to 30%."


2. It won't start building the Model S until mid-2012, while the current generation Tesla Roadster production ends in December 2011, leaving the company with little revenue just as it makes its biggest financial gamble.

3. To tide itself over, Tesla has arranged with Lotus to buy 2,400 "gliders" - Roadster bodies minus the Tesla driving gear - which it hopes to sell while cranking on the Model S through 2012.

3. There are only 130 prepaid orders for Roadsters not yet built as of June 30.

4. The 2,400 is a minimum; if Tesla can't sell them, it still owes Lotus.

5. If it needs more, it has to go back to Lotus with more money, and Lotus might have moved on by then.


6. Tesla has 2,600 deposits for the Model S worth $23 million. All such deposits are fully refundable.

7. There is one drivable prototype of the Model S, but final design/tooling/engineering isn't done.

9. Tesla has 24 months' worth of cash thanks to the IPO, Toyota's $50 million investment and the U.S. Department of Energy's $465 million loan - assuming the Model S launch goes smoothly and meets its deadlines. Anything changes, and Tesla will need more cash.


10. While Toyota has signed up for Tesla tech, Daimler has limited its business to a few test fleets, and has plans to build EVs with BYD Auto of China. After Tesla finishes its current Daimler project, there's nothing else on the boards with the German automaker.

On the bright side, the all-electric RAV4 prototype is getting rave reviews from Toyota execs.

[via Tesla 10-Q]