Tier 1 suppliers to OEMs
Our biggest customer added a CO2-per-part column to the RFQ. We have plant totals, not numbers per part.
Product carbon footprint for auto component suppliers
CO2 per part, with the quote.
The nomination form has a carbon line now. Fill it from your own plant.
Who are you?
RFQ · ANNEX CProduct carbon footprint · cradle to gate, per part
Ref.
RFQ-PT-0417
RFQ-PT-0417
- Part
- Crankshaft, forged, 12.0 kg
- Steel input
- 17.14 kg at 70% yield
- Steel
- India average
- Volume
- 50,000 a year
- Per part
- 53.18 kg CO₂e
- Steel
- 43.54 kg
- A year
- 2,659 t CO₂e
Per part number
Example. Illustrative part and figures.
The short answer
How do you calculate the carbon footprint of an auto part?
Divide the finished weight by your yield to get the steel input. Multiply it by the steel’s emission factor. Add your plant’s heat and power per part. That’s the cradle-to-gate footprint. ISO 14067 and the Catena-X PCF Rulebook set the method.
Last verified 3 October 2026. Sources at the end.
Sound familiar?
Tier 2 forges and foundries
The form asks for kg CO2e per part. We have one electricity bill and an oil register.
Exporters to the EU and US
The importer wants carbon per part on the PO. Our steel mill won’t give us their number.
Paraphrased from our conversations with component makers.
In a forged steel part, the steel is about four-fifths of the carbon.
Your plant is the rest. Most suppliers measure only that.
7.26 of 8.86 kg CO2e (82%) in the 2 kg part in Act 01, at India’s average of 2.54 t CO2 per tonne of crude steel (Ministry of Steel, 2023-24).
How much of the number is yours?
The same part, three ways. Watch the number, and how much of it is yours.
Why now
Who’s asking, and by when.
Sep 2024
Footprint at tender
Renault asks suppliers for component footprints at tender, steel and aluminium included.
End 2027
Catena-X grace ends
The PCF Rulebook v4 transition closes, and data quality ratings become mandatory.
1 Jan 2028
CBAM for parts
The EU has proposed CBAM on gearbox parts, wheels and suspension. Fasteners are covered already.
2%
Your OEM’s BRSR
Top listed companies can report partners at 2% or more of purchases, from FY 2025-26.
Free CO₂ per part calculator
One part, in ten seconds.
Set the weight, yield, steel and heating. See kg CO2e per part, and which change moves it most.
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How this is worked out
- Steel: India average 2.54 kg CO2 per kg of crude steel, 2023-24 (Ministry of Steel). DRI-EAF 1.47, scrap EAF 0.69, global 1.92 (worldsteel 2025).
- Induction heating 0.50 kWh per kg of input; oil-fired furnace 0.16 l per kg (UNIDO, BEE and GEF forging compendium).
- Other shop power 0.333 kWh per kg, derived from the furnace’s share of plant energy in the same source.
- Furnace oil 2.94 kg CO2 per litre (IPCC 2006). Grid 0.675 kg CO2 per kWh (CEA v22, 2025-26).
- Crude steel factors leave out rolling at the mill, so the result runs slightly low.
- Scenario estimate for forged steel parts. It isn’t a verified PCF.
Fill the RFQ line with a real number.
Your OEM’s RFQ annex. Same question, two answers.
RFQ_Annex_C_PCF.xlsxSheet: Sustainability · line 4
Line 4 State the cradle-to-gate product carbon footprint per part (kg CO2e), per the Catena-X PCF Rulebook. Give the primary data share and the data quality rating. Attach the method.
Wording modelled on OEM RFQ annexes.
- Win the nomination. Fill the carbon line others leave blank.
- Quote two options. Show the scrap-EAF steel option next to the standard one.
Straight answer: we build ISO 14067 calculations with the evidence behind them. Third-party verification is a separate step, and we’ll say when your buyer needs it. We aren’t a Catena-X service provider.
How it works
From your BOM to the OEM portal.
Carbon-OS reads your BOMs, routings, meters and bills. The same data rolls up to your Scope 1, 2 and 3 for BRSR and SBTi.
Connect
BOMs, routings, shop meters, energy bills.
Allocate
Energy to each part by routing and mass.
Calculate
kg CO2e per part, with each line labelled primary or secondary.
Share
RFQ annexes, OEM portals, CBAM data, BRSR.
Method and boundary
- Unit
- kg CO2e per part number, per plant.
- Boundary
- Cradle to gate. Use and end of life left out.
- Standard
- ISO 14067 and the GHG Protocol Product Standard. Catena-X Rulebook v4 for format and data quality.
- Material
- BOM × input weight × mill or database factor, flagged primary or secondary.
- Process
- Metered kWh and fuel per shop, allocated by routing and mass.
- CBAM
- Embedded emissions of steel and aluminium per CN code for EU importers.
- Factors
- More than a million emission factors, including CEA, IPCC and worldsteel.
From the field
What suppliers ask us first.
Forging suppliers
“Our OEM asked. We had plant totals.”
Paraphrased from a forging supplier. The ask is per part number, and plant totals don’t answer it.
What usually follows
“Our mill won’t send their number.”
Start with a labelled default, and ask the mill with the buyer’s form in hand. The calculator shows what it’s worth.
Glossary
Eight terms, in plain words.
- PCF
- The carbon footprint of one product, in kg CO2e per unit.
- Cradle to gate
- From raw material to your factory gate. Driving and scrapping are left out.
- Primary data share
- The part of a PCF built from your own measured data and factors.
- DQR
- Data quality rating: how good the inputs are.
- Catena-X
- The auto industry’s data network and PCF rulebook, used by European OEMs.
- IMDS
- The auto industry’s material database. It has mass, not carbon.
- Yield
- Finished weight over input weight. Scrap still carries the steel’s carbon.
- CBAM
- The EU’s carbon charge on imported steel, aluminium and, if adopted, some parts.
Where are you today?
Three questions. Your first steps.
See where we'd start with you.
Who asked you for a carbon number most recently?
What did they ask for?
What do you have today?
Questions suppliers ask.
What is a product carbon footprint for an auto part?
The CO2e from making one part, cradle to gate: the steel or aluminium in it, plus the energy your plant uses to shape it.
Why do OEMs ask suppliers for CO2 per part?
Bought-in parts are a big share of a car’s footprint. BMW uses supplier carbon footprint in contract awards. Renault has asked for component footprints at tender since September 2024.
What is the Catena-X PCF Rulebook?
The auto industry’s method for product footprints. Version 4 is based on ISO 14067, cradle to gate, with a 3% cut-off. Its transition runs to the end of 2027.
What is primary data share?
The share of a footprint where both the activity data and the emission factor are your own. A database grid or steel factor counts as secondary.
What drives the footprint of a forged part?
Usually the steel. At India’s average of 2.54 t CO2 per tonne of crude steel, steel is about 82% of a typical forged part.
How much does yield matter?
A lot. Every kilogram of flash and chips carries the steel’s carbon. Moving yield from 70% to 80% cuts the example part by 12%.
Does renewable power help an auto supplier’s footprint?
Yes, on your plant’s share. In the example, 100% renewable power cuts the footprint 18%.
Are auto parts covered by CBAM?
Fasteners (CN 7318) already are. A December 2025 proposal adds gearbox parts, wheels and suspension from 1 January 2028. It isn’t law yet.
Do Indian OEMs need supplier data for BRSR?
Value-chain disclosure is voluntary for the top 250 listed companies from FY 2025-26, for partners at 2% or more of purchases or sales.
I’m an MSME. Do I need software?
You need a number per part your customer accepts. Start with input weight, steel source and one year of energy bills.
Is a Climes product footprint verified?
No. We build ISO 14067 calculations with the evidence behind them. Third-party verification is a separate step.
Which grid factor do you use?
CEA’s CO2 Baseline Database v22: 0.675 t CO2 per MWh for 2025-26, unless you have contracted renewable supply.
Bring one part. We’ll work out its CO2.
Twenty minutes. Your weight, your yield, your steel. You leave with the number for the RFQ.
Book the 20-minute callor write to carbon-os@climes.io
Sources
- BMW Group: supplier carbon footprint as a contract-award criterion
- Renault Group: component footprints at tender since September 2024
- Catena-X PCF Rulebook v4: boundary, primary data share, cut-off, transition to end-2027
- Council of the EU, ST 16973/25 ADD 1: proposed CBAM codes, CN 7318 and 8708
- European Commission, IP/25/3088: downstream goods from 1 January 2028, proposed
- SEBI circular, 28 March 2025: value-chain disclosure, 2% threshold
- Ministry of Steel, Rajya Sabha reply: 2.54 t CO2 per tonne of crude steel
- worldsteel Sustainability Indicators 2025: route factors
- UNIDO, BEE and GEF forging cluster compendium: induction and furnace energy per kg
- IPCC 2006 Volume 2, Chapter 2: furnace oil factor
- CEA CO2 Baseline Database, version 22: grid 0.675
Facts on this page last verified 3 October 2026. Interactive figures are illustrative unless a source is named.