One of General Motors Co.’s most popular cars in Mexico is putting the lives of its drivers at a huge risk.

The Chevrolet Aveo failed tests on adult occupant protection, according to a new rating issued Monday by the Latin America branch of the New Car Assessment Program, an independent group that evaluates the safety of consumer vehicles. The sedan, which was the best-selling car in Mexico from September 2013 until August of this year, is marketed without airbags in the country, placing adult occupants at high risk for life-threatening injuries if accidents occur.

Crash tests conducted by Latin NCAP found the car’s body shell to be unstable, with particularly poor protection for the driver’s chest and head. The Aveo received zero out of five possible stars for adult occupant protection.

Cars sold in Latin American markets are not held to the same safety standards as those sold in the United States and Europe. Many vehicles in Mexico are not required to have basic features like antilock braking systems or airbags, and their absence has been cited as a big factor in the rise of car-related deaths in the country.

The results of the Aveo’s recent safety test were so disturbing that Maria Fernanda Rodriguez, president of the Latin division of NCAP, wrote to GM CEO Mary Barra about the dearth of safety features in the automaker’s cars sold in Latin American markets.

“It is hard to understand how GM can still sell a non-airbag version of the Aveo in Mexico with a high fatality risk,” Rodriguez wrote.

The NCAP tested a European Aveo model nine years ago with slightly better results. The European version, with four airbags, received a two-star rating, which allowed it to to squeeze past the European Union’s regulatory tests. But those standards were discarded for models sold in Mexico.

The disparity underscores long-standing criticism that automakers lower safety standards for Latin American models in order to offset decreasing profits. A 2013 report by the NCAP found that cars by GM, Suzuki and Renault-Nissan tested significantly lower than their equivalent models in Europe and America, suggesting that the companies placed a higher value on the safety of customers there than those in developing countries.

“Government regulations in Latin America are softer than they are in the U.S. and Europe, and that allows manufacturers to sell cars with lower safety standards,” said Alejandro Furas, secretary general of Latin NCAP. “They also want to make as much profit as possible by removing certain features. We’ve seen less reinforcements in the structure, so less metal material, and no airbags.”

The NCAP is now calling for dramatic changes from GM, which just last year announced a sweeping effort to encourage employees to speak up if they notice potential safety issues in cars.

“All the measures we’re talking about have been developed in the last 20 years,” Furas said of GM’s safety features. “There’s no reason not to put them in the cars we have in Latin America.”

Earlier this year, Nissan backed away from its defense of its Datsun Go car as complying with Indian safety regulations. After receiving backlash for the model’s weak body shell and airbags, Nissan pledged to improve safety features. It’s an indication that car companies are gradually — though still somewhat reluctantly — starting to take concrete actions toward reducing the sale of potentially harmful vehicles in emerging markets.

GM did not immediately respond to a request for comment.