Tesla Motors (NASDAQ:TSLA) made waves early in April when it began marketing its Model S luxury sedan as an affordable option -- if you factored in all the cost savings.

Some of Tesla's assumptions were dubious, but the Silicon Valley upstart may have been on to something. More and more, electric cars and plug-in hybrids are being sold on their cost benefits rather than their environmentally friendly ones. In this video, Motley Fool contributor John Rosevear takes a look at the new electric-car-marketing story -- and whether it's likely to finally resonate with reluctant consumers.