(CNN) Tesla CEO Elon Musk has made bold claims about the company's upcoming electric pickup. Now Ford, maker of America's most popular pickup truck, is already pushing back with a demonstration of what its planned electric F-150 could be capable of doing.

Ford F released video of a prototype electric F-150 towing a line of freight train cars weighing, according to Ford, over 1 million pounds. The truck, driven by F-150 chief engineer Linda Zhang, pulled the train for 1,000 feet.

After that was done, Ford added train cars carrying 42 F-150 pickups -- one for every year that the Ford F-series has been the bestselling truck in America -- and Zhang pulled the train again. With the trucks, the train weight rose to 1.25 million pounds, according to Ford.

Ford pointed out that this was a "one-time short event demonstration," in which the prototype was "towing far beyond any production truck's published capacity." Ford has not yet announced how much the production version of the truck will be capable of towing over long distances during day-to-day use.

To demonstrate the potential capabilities of its upcoming all-electric F-150, Ford released a video of the truck pulling more than 1 million pounds for 1,000 feet.

Ford did not say what sort of battery power, electric motors or gear ratios the prototype truck was using.