Starting a new car company isn't easy. Given the complexity and cost of cars, buyers are often hesitant to try an unknown quantity.

If a car gets even a hint of a reputation for unreliability, that task could turn impossible.

Which is why news that a Tesla Model S electric car on long-term test by Edmunds had its drive unit replaced four times posed such a risk for Silicon Valley carmaker Tesla Motors.

DON'T MISS: Tesla Model S Drive-Unit Replacements: How Big A Problem?

The company has now announced that it will increase the Model S drivetrain warranty to match that of the battery pack..

That means an 85-kilowatt-hour Model S will have an eight-year drivetrain warranty, with unlimited mileage, the company says. The 60-kWh cars will have eight years or 125,000 miles.

Elon Musk plugs a Tesla Model S into a Supercharger (Image: deanslavnich on Twitter)

Elon Musk plugs a Tesla Model S into a Supercharger (Image: deanslavnich on Twitter)

The battery-pack warranty itself had been expanded to cover failure under virtually any circumstances last year. 

The news came Friday afternoon in a post on the Tesla Motors blog.

To sweeten the latest update even further, there is no limit on the number of owners during the warranty period, and Tesla will apply the newly-extended warranty retroactively to all Model S plug-ins currently on the road.

Tesla CEO Elon Musk said he believes this should have been the company's policy from the beginning.

ALSO SEE: Tesla Roadster To Get Replacement Battery, 400-Mile Range: Musk

Musk said Tesla stands by the belief that electric cars are inherently more reliable than internal-combustion vehicles--because, among other things, they have fewer moving parts to break--and that the warranty policy should reflect that.

However, it may well also be a response to recent media coverage of the drivetrain replacements.

Both Edmunds and Motor Trend chronicled the replacement of drive units in their long-term test cars. That's hardly the kind of publicity a car company wants.

2012 Tesla Model S beta vehicle, Fremont, CA, October 2011

2012 Tesla Model S beta vehicle, Fremont, CA, October 2011

The Tesla Model S drivetrain was previously covered under the four-year / 50,000-mile vehicle warranty, which fell somewhat short of the powertrain warranties offered by many established carmakers.

So Tesla's adjustment to that warranty is meant not only to reassure existing customers, but also to fill a gap in what Musk has envisioned as "the world's best service and warranty program."

In his statement, Musk acknowledged that extra warranty repairs will cost Tesla in the short term.

Those costs may pale against the long-term public relations benefits of being seen as a company that does everything it can to treat owners well and do the right thing.


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