New York (CNN Business) On Sunday, Ford will announce what is possibly the biggest change ever in the 55-year history of the Mustang.

The automaker will unveil a vehicle bearing the Mustang brand that's not a two-door car.

Called the Ford Mustang Mach-E, it's a fully electric crossover SUV that will wear the Mustang's chrome pony.

Ford has apparently learned from brands like Porsche, Lamborghini and Jeep that even ardent fans will forgive the use of a brand name on a once-unthinkable type of vehicle. That's as long as the new vehicle maintains some core aspects of the original and as long as the original vehicle that made the brand carries on as well.

Ford provided this teaser image of the crossover SUV before Sunday's launch.

For instance, Porsche fans were once outraged by the Cayenne SUV . But because Porsche still makes sports cars like the 911 and the Cayenne can credibly claim to be "the Porsche of SUVs," the brand remains strong. Likewise, Jeep has been able to make crossover SUVs that will rarely leave pavement as long as those crossovers are available in tough "Trail Rated" versions and Jeep keeps making the ultra-rugged Wrangler.

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