NEW YORK — Coke Zero, apparently, is your father's diet drink. Women may be the core customers for no-cal drinks, but Coke Zero also is bringing in men — from college boys to soccer dads — with black packaging, a different sweetener and irreverent marketing that appeals to men.

Zero is Coca-Cola's first new product hit after a long list of attempts — from lime to vanilla flavors — that started strong and fizzled fast.

Men are about 45 percent of Diet Coke drinkers but about 55 percent of Coke Zero buyers. It has a stronger, more Coke Classic-like flavor and seems to be holding onto male customers who've become more calorie-conscious with age but still want more flavor than most diet colas.

"This product tastes like Coke," says Caren Pasquale Seckler, Coke's group director of diet cola brands in North America. "There's a broad group of young adult males who are looking for full flavor and, oh, by the way, it has zero calories."

Seckler won't say exactly how the taste/calorie combination is achieved but notes the sweetener is a mix of aspartame and acesulfame potassium (known as Ace-K), which gives Zero a more sugarlike taste than aspartame alone.

"When we first launched the brand, we probably didn't talk about the taste as much as we should have," Seckler says.

"It's got a fairly sophisticated flavor system and complex ingredients to help replicate the taste of regular Coca-Cola," says beverage expert John Sicher, editor of industry tracker Beverage Digest.

A year ago, black cans and labels replaced white because of sales success for Zero with black packaging in Australia and the United Kingdom. "We learned from other countries that the dark color connoted a stronger, bolder flavor," she says.

Advertising of the product is also stronger and bolder. Today's Coke Zero TV ads — shot "Borat"-style — feature two supposed "brand managers" for Coca-Cola Classic approach real-life lawyers and tell the incredulous attorneys that they want their help to sue Coke Zero for "taste infringement."

Apparently the approach is working. Zero, out two years, is still growing. Sales volume is up 34 percent in North America year-to-date vs. the same period in 2006.

Third-quarter results out this month show Zero with a nearly 1.3 percent share in carbonated beverages in North America — enough in the $90 billion beverage business to make a bottler bubble over.

"It's got a fairly sophisticated flavor system and complex ingredients to help replicate the taste of regular Coca-Cola."