Long-term ownership of electric vehicles remains a touchy subject. Unlike conventionally-powered cars, EVs simply haven't been around long enough to get a clear idea of what happens once the miles really start to pile up. That said, there are some promising early signs as a Tesla Model S owner is about to reach 750,000 miles in his car. Tesla even went as far as to stop recommending scheduled maintenance on its vehicles last year as they were simply that reliable.

All of which makes the company's latest move more curious, namely, the rather significant shortening of the warranty for used Teslas. As reported by Electrek, Tesla previously offered a two- to four-year warranty on used Model X SUVs and Model S sedans.

If the vehicle was less than four years old and had under 50,000 miles on the clock at the time of delivery, these models were covered by a four-year/50,000-mile used vehicle limited warranty. If the models had over 50,000 miles or were more than four years old - but less than 100,000 miles and were less than six years old - the used vehicle limited warranty would run for two years following delivery or up to 100,000 miles.

In each case, the original warranty isn't extended or altered, while the balance of the original battery/drive unit limited warranties still applies. However - just ahead of the brand's imminent Q3 financial report - Tesla has now diminished its used vehicle warranty to just one year or 10,000 miles once the original warranty expires.

Effectively, this means that if you want to buy something like a 2017 Tesla Model S with around 40,000 miles, the updated used vehicle warranty covers only a fifth of the mileage or a quarter of the time period compared with the previous warranty. A 2019 used Tesla would be a much better bet, as the bulk of the new vehicle warranty would still need to run its course. But it's disappointing news for shoppers hoping to save by purchasing a slightly older model.

This change comes just after Tesla removed its seven-day return policy, another item that significantly enhanced consumer trust in the brand. Don't expect any clear cut answers from Tesla on these changes, though, as the company no longer has a PR department. It remains to be seen if the changes have an impact on sales of used Teslas.