Short answer
DENUE lists 95 engine and powertrain parts plants with 11 or more staff in Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 78 have 51 or more staff, and 52 of those match an IMMEX program on exact name and postal code. Guanajuato has the most, with 38. Each plant still needs its own checks.
Key facts
- Activity codes (SCIAN)
- 336310 and 336350
- Plants, 11+ staff
- 95
- Data
- INEGI DENUE bulk files, 25 Sep 2026; IMMEX directory, August 2026 edition
About engine and powertrain parts
Powertrain plants make engine, transmission and driveline parts. The work is machining heavy and often safety or emissions relevant.
The numbers by state
| State | Plants, 11+ staff | With 51+ staff | With an IMMEX match |
|---|---|---|---|
| Guanajuato | 38 | 34 | 25 |
| Querétaro | 25 | 17 | 14 |
| Aguascalientes | 18 | 15 | 12 |
| San Luis Potosí | 14 | 12 | 8 |
| Four states | 95 | 78 | 59 |
| Staff band | Plants |
|---|---|
| 11 to 30 | 7 |
| 31 to 50 | 10 |
| 51 to 100 | 12 |
| 101 to 250 | 20 |
| 251 or more | 46 |
What to ask a powertrain supplier
Registries show that a plant exists and exports. These questions cover what they cannot.
- Casting or forging sources, and machining capability in house.
- Cleanliness and leak-test requirements they already meet.
- End-of-line testing and how results are stored.
- Programs they run today and their launch history.
- IATF 16949 status, confirmed with the certification body.
Checks before you approach a plant
- Confirm the plant in DENUEName, address, activity code and staff band.
- Check its IMMEX programStatus and type, matched on legal name and postal code.
- Search the SAT 69-B listBy RFC where you have it, otherwise by exact name.
The verification guide explains each step and where it stops.
Frequently asked questions
How many engine and powertrain parts plants are in the Bajío?
INEGI’s DENUE lists 95 engine and powertrain parts plants with 11 or more staff across Aguascalientes, Guanajuato, Querétaro and San Luis Potosí. 78 of them have 51 or more staff. Testigo counted these from INEGI’s bulk files on 25 September 2026.
Which Bajío state has the most engine and powertrain parts plants?
Among the four states Testigo counted, Guanajuato has the most engine and powertrain parts plants in DENUE, with 38 of 95, followed by Querétaro (25). Plants elsewhere in Mexico are outside Testigo’s pilot, and counts are establishments in INEGI’s directory as of 25 September 2026.
Do engine and powertrain parts plants in the Bajío export under IMMEX?
Some do. 59 of the 95 plants match an IMMEX program on exact name and postal code, and 52 of the 78 with 51 or more staff. A plant with no match may still export through a shelter company’s program, so ask which entity holds it.