Material Insights · Understanding the Material World

Combustion road vehicles: Equipment and suppliers

Inside the engine, turbocharger and the precious-metal catalyst

What this tab covers For each method, the main pieces of equipment, who makes them (by region) and what they are made of (bill of materials).

A combustion vehicle is built around the engine, its fuel system and its exhaust aftertreatment, plus a gearbox. Gas vehicles add high-pressure tanks.

Petrol car

Spark-ignition engine311

Turns fuel energy into crankshaft work.

Japan and Korea Toyota, Hyundai, Honda Europe Volkswagen, Stellantis United States GM, Ford China SAIC, Geely
Bill of materials
  • Block and cylinder head: cast aluminium alloy or cast iron
  • Crankshaft, pistons, valves: forged steel, aluminium pistons
  • Fuel injection and ignition: high-pressure injectors, spark plugs, engine control unit
Three-way catalytic converter23

Converts carbon monoxide, unburnt fuel and nitrogen oxides into CO2, water and nitrogen.

Europe Umicore (Belgium), BASF Environmental Catalyst and Metal Solutions (Germany), Johnson Matthey Clean Air (United Kingdom) Japan and Korea Cataler (Japan)
Bill of materials
  • Catalyst: platinum, palladium and rhodium on a ceramic honeycomb

Diesel truck and bus

Heavy-duty diesel engine45618

High-compression engine with turbocharger and common-rail injection; 43-55% brake thermal efficiency.

United States Cummins China Weichai Power
Bill of materials
  • Block and head: compacted graphite or grey cast iron
  • Turbocharger: nickel superalloy turbine wheel
  • Waste heat recovery (in prototypes): organic Rankine cycle turning exhaust heat into extra work
Exhaust aftertreatment23

Particulate filter and selective catalytic reduction (urea dosing) to meet Euro VI, China VI and US limits.

Europe Umicore (Belgium), BASF Environmental Catalyst and Metal Solutions (Germany), Johnson Matthey Clean Air (United Kingdom) Japan and Korea Cataler (Japan)
Bill of materials
  • Diesel particulate filter: silicon carbide or cordierite ceramic
  • SCR catalyst: copper or iron zeolite

CNG and LPG vehicles

High-pressure CNG cylinders1617

Store compressed methane on board.

United States Luxfer (UK-registered group; cylinders sold in North America) Europe Hexagon Agility (part of Hexagon Composites, Norway)
Bill of materials
  • Type 4 cylinder: polymer liner wrapped in carbon fibre composite
  • Type 1 cylinder: all steel, heavier and cheaper

Sources

  1. TNGA powertrain: 2.5-litre Dynamic Force engine Toyota Motor Corporation, 2016
  2. The ever-improving efficiency of the diesel engine ICCT, 2015
  3. Weichai unveils diesel engine with 53.09% thermal efficiency DieselNet, 2024
  4. SuperTruck II team reaches brake thermal efficiency goal Heavy Duty Trucking (truckinginfo.com), 2021
  5. Three Chinese automakers enter global top 10 as 2025 sales rankings finalized (press compilation of company reports) CarNewsChina, 2026
  6. G-Stor Go Type 4 CNG cylinders Luxfer Gas Cylinders, 2025
  7. Hexagon Agility receives new wave of orders for natural gas fuel systems for North American heavy-duty trucks Hexagon Composites ASA, 2025
  8. 2022 Annual Merit Review: Cummins/Peterbilt SuperTruck II US Department of Energy, Vehicle Technologies Office, 2022
  9. BASF Factbook: Catalysts (Environmental Catalyst and Metal Solutions; competitors in mobile emissions catalysts) BASF (company source), 2026