Mexico: Light-duty: Emissions

Overview

 * Standard type: Conventional pollution emission limits
 * Regulating body: Secretaria de Medio Ambiente y Recursos Naturales (SEMARNAT)
 * Current standard: NOM-042-SEMARNAT-2003
 * Applicability: Vehicles with GVW ≤ 3,857 kg

History
Mexican emissions requirements for new vehicles and engines are adopted by the Secretaria de Medio Ambiente y Recursos Naturales (SEMARNAT). Manufacturers can chose to comply with emission limits based on either US- or European-based standards.

Emissions standards for both light- and heavy-duty vehicles were first established in 1988 and became effective in model year 1993 (NOM-044-ECOL-1993).

Mexican light-duty standards were later updated with NOM-042-ECOL-1999, which became effective with MY 2001 and strengthened standards to be equivalent to the US Tier 1. With NOM-042-SEMARNAT-2003, a mix of US Tier 1/2 and Euro 3/4 standards has been required since 2004.

Light-Duty Vehicle Classification
Light-duty vehicles are defined as vehicles of Gross Vehicle Weight (GVW) &le; 3857 kg. Passenger cars (PC) are defined as vehicles with up to 10 seats, including the driver. Light trucks are classified into four groups—corresponding approximately to the US Light Duty Truck 1 to 4—based on the GVW and the test weight (weight of the vehicle with full fuel tank) as follows:
 * CL1: GVW &le; 2722 kg, test weight &le; 1701 kg
 * CL2: GVW &le; 2722 kg, test weight 1701 - 2608 kg
 * CL3: GVW 2722 - 3857 kg, test weight &le; 2608 kg
 * CL4: GVW 2722 - 3857 kg, test weight 2608 - 3857 kg

Weight ratings based on the European grouping for passenger cars and light commercial vehicles using a vehicle’s reference mass (weight of vehicle with full tank of fuel + 100 kg) are also used:
 * CL Class 1: reference mass &le; 1305 kg
 * CL Class 2: reference mass &gt; 1305 kg but &le; 1760 kg
 * CL Class 3: reference mass &gt; 1760 kg

MY 1993-2003
Emission standards for light-duty vehicles (MY 1993-2003) are summarized in the table below. The standards were based on US regulations and Federal Test Procedures (FTP) (FTP-75). The 1993 requirements were based on the US 1981 emission standards, while the 2001 requirements represent the US Tier 1 standards without On Board Diagnostics (OBD) II provisions.

The standards apply both to gasoline and diesel vehicles, with the exception of NOx standards, as specified, and the PM standard that applies only to diesel vehicles. Natural gas and liquefied petroleum gas (LPG) vehicles have the same standards as gasoline vehicles.

Gasoline, natural gas, and LPG vehicles of all classes and all model years must also meet an evaporative (SHED) limit of 2 g/test.

MY 2004 and later
Limit Values

Standards that apply to model year 2004 and later are based on US Tier 1 and Tier 2 standards and Euro 3 and Euro 4 limits. New vehicles must meet the standards based on US Tier 1/2 limits or based on Euro 3/4 limits, as outlined in the tables below. Vehicles meeting these standards are also required to be equipped with OBD. Gasoline vehicle standards also apply to natural gas and LPG vehicles.

While the standards are based on US EPA limits and European limits, they are not necessarily structured the same way. For example, the NOx and PM limits defined by the “A” standard are a combination of 50,000 mile and full useful life US EPA Tier 1 limits. For the “B” and “C” standards, the PM limits do not change, (i.e., they stay at the Tier 1 limits) while the NOx standards decrease to limits based on 50,000 mile US EPA Tier 2 values. The NOx limit for the “B” standard is US Tier 2 Bin 10 and for the “C” standard is Bin 7 (for lighter vehicles) and Bin 9 (for heavier vehicles). With the exception of “B” standard for gasoline, LPG and natural gas, the standards are equivalent to Euro 3 and 4 limits. Note the different durability requirements for the US based standards (80,000 km) and Euro based standards (100,000 km).

Gasoline, natural gas, and LPG vehicles of all classes and all model years must also meet an evaporative (SHED) limit of 2 g/test.

Emission durability requirements
 * 80,000 km / 50,000 mi for US EPA option, or 100,000 km for European option

Phase-in schedule

Vehicles meeting the “A” standard are those produced between 2004 to 2009. Vehicles meeting “B” standard are those produced from 2007 to “Year 3”—2 calendar years after “Year 1”. Vehicles meeting “C” standard are those produced starting in “Year 1”. The phase-in schedules for vehicles meeting B and C standards are as follows:

Fuel quality requirements

An important factor in the phase-in of these vehicles is the introduction of gasoline with an average sulfur content of 30 ppm and a maximum of 80 ppm, as well as diesel fuel with a sulfur content of 15 ppm. NOM-086-SEMARNAT-SENER-SCFI-2005 set in place a timeline for such sulfur reduction goals to be met for gasoline and diesel fuel sold in Mexico. The calendar year that these fuels become available nationally is referred to as “Year 1” (Año 1), which according to NOM-086 should have been 2009. However, this deadline was not met and fuels containing the aforementioned sulfur levels are not yet available nationally.

Regulatory Documents
NOM-042-SEMARNAT-2003, effective 2004, a mix of US Tier 1/2 and Euro 3/4 standards

NOM-042-ECOL-1999, effective 2001 and based on US Tier 1

NOM-044-ECOL-1993

Additional Resources
Secretaria de Medio Ambiente y Recursos Naturales (SEMARNAT) webpage

SEMARNAT mobile source emissions regulation page