Yet most of these vehicles consume much more fuel — and release much more greenhouse gas emissions — than they should. Of course, moving Mexican cities towards sustainable mobility built around electric transport, walking, and cycling is the most beneficial way to improve the environment, economies, and society. However, as fuel-burning private vehicles remain a constant, policymakers must focus on minimizing their impact on the air and climate. While neighborhing nations have moved ahead with cleaner, more efficient vehicle options, Mexico still lags behind. Now, there is an opportunity to advance change for Mexico.

Three leading civil society organizations — ITDP Mexico, the Mexican Center for Environmental Law (CEMDA), and El Poder del Consumidor (EPC) — recently joined together to urge the national Mexican Ministry of Environment and Natural Resources (SEMARNAT) to take a bold step forward as it updates NOM-163, the country’s main policy overseeing on vehicle emissions and fuel efficiency. The organizations say this update is a once-in-a-decade opportunity to enshrine protections for the climate, save Mexican households more money, and reduce dependence on imported fossil fuels — if, and only if, the process remains transparent and free from corporate interference.

Setting the Standard

Known formally as NOM-163-SEMARNAT-SCFI-2023, the rule sets limits on CO2 emissions and establishes energy efficiency standards for light vehicles sold in Mexico. Though it may sound technical, its impact shapes what kind of cars are available on the Mexican market, how much fuel they consume, and how much pollution they produce. Stronger standards mean cleaner air, lower fuel bills, and greater energy security for the country. When coupled with more investment in sustainable mobility policies and projects, such vehicle standards is crucial to helping Mexico meets its urban emissions and development goals.

Current President Claudia Sheinbaum’s 100-Point National Plan calls for modernizing environmental and energy regulations to accelerate Mexico’s transition to a low-carbon economy. Updating NOM-163 is a cornerstone of that effort. However, as has happened in the past, some stakeholders of the automotive industry may push to weaken the rule with loopholes and “’lexibility mechanisms’ that make it appear ambitious while allowing high emissions to continue.

Learning from Past Mistakes

Previous versions of NOM-163 were compromised by corporate influence. Instead of cutting emissions, the regulation was diluted with exceptions and credits that rewarded manufacturers for actions that did not result in real reductions. As a result, Mexico’s most important vehicle emissions policy failed to deliver its promise.This time, civil society organizations like ITDP Mexico are warning  SEMARNAT to not repeat past mistakes. Instead, the government should:

• Set ambitious goals aligned with the Glasgow Climate Pact (adopted at COP26 in 2021) and Mexico’s plans for vehicle electrification by 2030 and 2035;
• Eliminate loopholes and false credits that allow companies to meet targets without actual improvements in efficiency;
• Ensure transparency, by requiring open, digital data formats and standardized vehicle information so that citizens, researchers, and institutions can monitor compliance.

For Anaid Velasco of CEMDA, NOM-163 is not just a technical issue; it’s about fundamental mobility and environmental rights for Mexican communities. “NOM-163 must become a true climate and environmental tool,” Velasco said. “Human rights such as a healthy environment and health should not be conditioned by purely economic criteria. Mexico cannot waste the opportunity to fulfill its international commitments and protect fundamental human rights.”

An ambitious standard would also bring relief to families. Low-income households are often the most affected by high fuel prices and poor air quality. A more efficient vehicle fleet reduces household spending, improves air quality, and strengthens Mexico’s energy independence. Each improvement in fuel performance means less reliance on gasoline and diesel from abroad, making the country more resilient to global energy market fluctuations and reinforcing national sovereignty.

A Moment for Change

For over a decade, Mexico has aimed to align its vehicle standards with those of its neighbors in the U.S. and Canada as part of regional trade commitments. But progress has been slow. By 2027, new cars in Mexico will still be allowed to consume about 3% more gasoline than those in the U.S. In addition, Mexico’s standards are up to twice as flexible, allowing manufacturers to pollute more while still appearing to comply. This disparity undermines both competitiveness and consumer trust.

“Mexico has all the commercial and technological conditions to adopt ambitious efficiency standards,” said Bernardo Baranda of ITDP Mexico. “The international market already demands these levels, and our plants export to countries with stricter standards, which is shameful. There is no excuse for continuing with weak regulations.”

Mexico’s ability to meet its Nationally Determined Contributions (NDCs) under the Paris Agreement will depend heavily on the strength of NOM-163. The transport sector remains one of the country’s largest sources of emissions, and this regulation is its primary tool for reducing them. The new NOM-163 is the last call to put consumers and the environment at the center of policy design.

The coming months will determine whether Mexico continues down a path of weak standards and missed opportunities, or takes a decisive step toward a cleaner, fairer future. For the organizations pushing for reform, the choice is clear. A stronger NOM-163 means more efficient vehicles, cleaner air, lower costs for families, and a more resilient Mexico.