Material Insights · Understanding the Material World

Internal combustion engines and gensets: Equipment and suppliers

Blocks, turbochargers and alternators inside a genset

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 genset is an engine, an alternator and a control system; a vehicle engine pairs the same core with a gearbox. Key enabling parts are fuel injection, turbochargers and aftertreatment.

Diesel and gas gensets

Reciprocating engine13413

Converts fuel to shaft power.

United States Caterpillar, Cummins Europe Wärtsilä, INNIO Jenbacher, Rolls-Royce Power Systems (mtu), Everllence, Volvo Penta China Weichai Power
Bill of materials
  • Block, heads and crankshaft: cast iron and forged steel
  • Cylinders: up to 500 mm bore in the largest gas engines
  • Turbocharger and fuel injection: high-temperature alloys and precision steel
Alternator4111213

Synchronous generator turning the crankshaft's rotation into AC at grid frequency.

United States Caterpillar, Cummins, Generac, Rehlko (formerly Kohler Energy) Europe Rolls-Royce Power Systems (mtu), Volvo Penta
Bill of materials
  • Stator and rotor: copper windings in laminated electrical steel
Controls, switchgear and fuel system4

Synchronise sets to the grid or a load, start them automatically and store fuel.

Europe Wärtsilä, INNIO Jenbacher United States Caterpillar
Bill of materials
  • Grid-forming batteries in hybrid plants: for example 1.1 GWh with a 4 GW Caterpillar project

Petrol and diesel vehicle engines

High-efficiency engine1213

Delivers wheel torque; peak efficiency set by compression, combustion and friction.

Japan and Korea Toyota China Weichai Power United States Cummins
Bill of materials
  • Cylinder block and head: aluminium or cast iron; 80.5 x 97.6 mm bore and stroke in Toyota's 2.0-litre
  • Aftertreatment: catalysts and particulate filters to meet China VI and Euro VI rules

Sources

  1. Weichai unveils diesel engine with 53.09% brake thermal efficiency DieselNet, 2024
  2. Toyota Unveils More New Gasoline ICEs with 40% Thermal Efficiency SAE Mobility Engineering, 2018
  3. Wärtsilä 50SG gas engine power plant Wärtsilä, 2025
  4. Engine Power Plants Surge as Data Centers Drive Unprecedented Demand POWER Magazine, 2026
  5. Generac reports fourth quarter and full-year 2025 results Generac Holdings, 2026
  6. Kohler Energy changes name to Rehlko Equipment World, 2024
  7. Cummins Inc. Form 10-K for fiscal year 2025 Cummins / US SEC, 2026