Gas Turbine vs. Reciprocating Engine: Power, Efficiency & Cost Showdown
A gas turbine is a continuous-combustion engine that spins a shaft with hot, expanding gases. A reciprocating engine uses pistons moving back and forth in cylinders to turn a crankshaft.
Pilots see “turboprop” on flight tickets, drivers spot “V6” badges, and data-center engineers debate backup gensets—yet all call them “engines.” The everyday word blurs two wildly different machines, so people lump them together when they shop for power.
Key Differences
Gas turbines spin at 15,000–50,000 rpm, reach 40%+ thermal efficiency at full load, cost $2–4 million per MW, and favor constant power. Reciprocating engines idle efficiently, hit 45% in diesel form, cost $0.8–1.2 million per MW, but need frequent overhauls.
Which One Should You Choose?
Pick a turbine for 24/7 baseload, aviation, or remote pipelines where weight trumps price. Choose reciprocating for hospitals, ships, or peaking plants needing rapid start-stop cycles and lower upfront capital.
Do turbines use less fuel at part load?
No. Their efficiency drops sharply below 50% load, while reciprocating engines hold steady down to 30%.
Which lasts longer between overhauls?
Industrial turbines run 30,000–50,000 hours; large diesels need major service every 15,000–20,000 hours.