(Reuters) – Hyundai Motor Co has been sued for allegedly misleading consumers sensitive to high gas prices that its popular 2011 and 2012 Elantra model is more fuel efficient than it actually is.

The lawsuit filed by the public interest group Consumer Watchdog claims that TV advertisements touting “the 40 Mile Per Gallon Elantra” reflected only highway mileage, not city or combined highway/city mileage.

It claimed that required disclosures of the estimated city mileage, 29 miles per gallon, appeared only briefly in “tiny, faint text” that viewers could not read without freezing their screens. Disclosures in magazine ads for the car were illegible or nonexistent, the complaint added.

The plaintiff, Louis Bird of Sacramento, California, claimed he would not have bought his 2011 Elantra but for Hyundai’s advertising, and is paying more than he expected to refuel.

His lawsuit seeks class-action status and unspecified damages for alleged violations of California consumer protection and fraud laws. The lawsuit was filed on July 3 in a California state court in Sacramento.

Hyundai North America, in a statement, referred to tests by the government and three widely-read magazines that suggest the advertised fuel economy is realistic. The South Korean company did not specifically address allegations in the complaint that it should have made fuller disclosures in its advertising.

On May 9, a state judge in Los Angeles ruled in favor of Honda Motor Co in reversing a $9,867 award to a Civic hybrid owner who accused the Japanese automaker of fraudulently overstating its fuel economy in its advertising.

Known for its sleek styling, the five-seat Elantra was the 19th best-selling car or truck in the United States from January to June, with 97,769 vehicle sales.

The case is Bird v. Hyundai Motor America et al, Superior Court of California, Sacramento County. (Reporting by Jonathan Stempel in New York; Editing by Tim Dobbyn)