Mention Herb Chambers to anyone around Boston and more likely than not they know who he is: the guy with tortoise-shell glasses on billboards who sells more cars than anyone in New England.

Now you can add this about Chambers: He’s a billionaire with a $1.5 billion fortune, according to the Bloomberg Billionaires Index. The value of his 55 dealerships, selling everything from Buicks to BMWs, got a nice bounce in March after Warren Buffett purchased the nation’s largest closely held car retailer, Van Tuyl Inc., at a big premium.

"I’d be disappointed if I wasn’t a billionaire, after working all these years," Chambers, 73, says with a laugh in a recent interview.

Car salesmen are inherently optimistic but Chambers has a reason for feeling good these days. U.S. auto sales are at their highest level in more than a decade and the number of dealers has fallen 20 percent since the recession, lessening competition.

All this should push up revenue from his dealerships about 6 percent this year to almost $2.7 billion, Chambers said. Berkshire Hathaway Inc.’s purchase of Van Tuyl, which does business in 10 states, showed how strong the market is for the handful of very large closely held dealerships such as Chambers’s, the 12th largest overall.

He achieves billionaire status based on the $4.1 billion cash Buffett paid for Van Tuyl, as well as accounting for a smaller fortune Chambers made in his first career as the world’s top copier salesman.

Buffett Photo

Chambers is hardly in hiding, of course. About one in seven people in the state buy a car from his dealerships each year, nearly all of which bear his name -- Mercedes and Bentley bar dealer names. Off hours, Chambers is often found dining at Davio’s, a Beantown power spot owned by his best friend. Now and again his 197-foot yacht, the Excellence V, makes an appearance in the harbor.

While the billionaire says he’s enjoying the business more than ever, the prominence in his office of a photo of him with Buffett from a recent National Automobile Dealers Association meeting begs the question: Is he going to sell too?

"At some point in time I absolutely would sell," Chambers said. "There’s a lot of private equity money trying to get into the automobile business. A lot of the investment banking firms, several of them in the Boston area, have been talking to me."