How do I calculate the carbon footprint of an alloy wheel?
Most of an alloy wheel is aluminium: multiply the cast weight, including gates and swarf, by the alloy supplier's figure. Add melting, low pressure casting, heat treatment, machining and painting energy, then divide by wheels passed.
Material
- Aluminium alloy by cast weight.
- Swarf and rejects remelted.
- Paint and lacquer.
Process
- Melting furnaces.
- Low pressure die casting and heat treatment.
- Machining, painting and testing.
Per wheel
Report per wheel by size and finished weight. Recycled alloy lowers the figure.
Worked example: alloy wheel unit per wheel (one month)
- Electricity: 150,000 kWh x 0.710 = 106,500 kg CO2
- PNG: 50,000 SCM x 2.05 = 102,500 kg CO2
- Wheels produced: 30,000
- Plant total: 209,000 / 30,000 = 6.967 kg CO2 per wheel
- Add aluminium alloy for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.