Instead of preaching about the evils of General Motors’ Hummer H2, with its hulking frame and 10-mile-per-gallon fuel economy, the Sierra Club has launched a new website to mock the mega-SUV: www.hummerdinger.com. “G.M. celebrates Hummer’s state-of-the-art 1950’s engine technology with some of today’s hottest stars,” reads a mock story on the site, which goes on to note that Pat Boone and Frankie Avalon have been lined up as endorsers. The site also features a cartoon movie parody of Hummer TV ads, a quiz to see if you’re a “Hummer hunk,” and — because this is a product of the Sierra Club, after all — a way to send G.M. a “Hummerdinger zinger,” which calls on the company to boost the gas mileage of its fleet. G.M. dismisses the criticism, noting that sales of the H2 amount to just one half of 1 percent of the U.S. vehicle market.