"Just give me a Pepsi free."
"If you want a Pepsi pal, you're going to pay for it!"
When Marty McFly found himself in 1955 Hill Valley in the first Back to the Future, he also found that the era of muscle cars and diners was hardly the same era of choice he was used to in 1985. There was no sugar-free Pepsi. Just plain ol' Pepsi.