ANYONE who worries that the hard sell has vanished from the American scene should look at Yoo-Hoo chocolate drink's ''Chug-a-Can Wide Mouth'' and at Mountain Dew's ''Mega Mouth Slam Can.'' The wider pop-top openings are shrilly proclaimed by banners announcing that these are drinks you can chug.

The same sort of tops -- with an opening about 40 percent larger than usual -- have been found on some beer cans since the summer of 1996, when Coors introduced its Widemouth can and put a trademark on the product. But for beer makers, ''wide'' is not about chugging. No, the Widemouth instead offers ''the same smooth drinking experience consumers enjoy and prefer in a glass,'' Patrick Edson, the Coors brand manager, said. Miller and Budweiser have moved to wider, too.

Same technology, different spin. The wide-mouth beer cans offer ''less glug,'' as one beer distributor put it, while soda brags of ''more chug.''

''Wide mouth is fashionable,'' said Jim Fisher, marketing manager of Ball Metal, a manufacturer of the cans.