---
title: "Internal Combustion Engine — AP Euro Definition & Guide"
description: "The internal combustion engine burns fuel inside the engine itself, powering the Second Industrial Revolution (1870-1914) and new industries like automobiles."
canonical: "https://fiveable.me/ap-euro/key-terms/internal-combustion-engine"
type: "key-term"
subject: "AP European History"
unit: "Unit 6"
---

# Internal Combustion Engine — AP Euro Definition & Guide

## Definition

The internal combustion engine is an engine that burns fuel (like gasoline) inside the engine itself to produce power. Alongside electricity, it replaced steam as a dominant power source during the Second Industrial Revolution (c. 1870-1914), creating new industries and transforming transportation.

## What It Is

The internal combustion engine burns fuel inside a chamber within the engine, rather than heating water in a separate boiler the way a [steam engine](/ap-euro/key-terms/steam-engine "fv-autolink") does. That design makes it smaller, lighter, and more efficient than steam power, which means it can fit inside a vehicle instead of staying bolted to a factory floor.

For [AP Euro](/ap-euro "fv-autolink"), the internal combustion engine is one of the signature technologies of the Second Industrial Revolution (c. 1870-1914). Along with electricity, steel from the Bessemer process, and chemicals, it marks the shift from the coal-and-steam world of the First Industrial Revolution to a new wave of industry. The CED's essential knowledge (KC-3.2.IV.B) is the core of the story here. New, efficient methods of [transportation](/ap-euro/unit-4/18th-century-society-demographics/study-guide/rjkMnqoJer0rcF0dDea9 "fv-autolink") created entirely new industries, improved the distribution of goods, increased consumerism, and enhanced quality of life. The automobile industry is the textbook example, and it exists because of this engine.

## Why It Matters

This term lives in Topic 6.3 (The [Second Industrial Revolution](/ap-euro/key-terms/second-industrial-revolution "fv-autolink")) in [Unit 6](/ap-euro/unit-6 "fv-autolink"): Industrialization and Its Effects. It directly supports AP Euro 6.3.A, which asks you to explain how innovations and advances in technology led to economic and social change, and AP Euro 6.3.B, which covers how industrialization shaped economic and political development from 1815 to 1914. The internal combustion engine is your go-to piece of evidence for the claim that the second industrial revolution wasn't just "more of the same." It ran on new power sources, spread industry to more areas of Europe (KC-3.1.III), and built a more integrated, global economy with rising consumerism (KC-3.1.III.B and KC-3.2.IV.B). If a question asks what made the period after 1870 different from the early 1800s, this engine plus electricity is the answer.

## Connections

### [First Industrial Revolution (Unit 5/6)](/ap-euro/key-terms/first-industrial-revolution)

The first revolution ran on coal, steam, and textiles. The internal combustion engine is one of the clearest markers that the second revolution had moved on to new power sources. Pairing the two is how you write a strong change-over-time argument about [industrialization](/ap-euro/unit-6/context-industrialization/study-guide/giIfSjTUSAVm82neDXdT "fv-autolink").

### [Automobile Industry (Unit 6)](/ap-euro/key-terms/automobile-industry)

The internal combustion engine is the technology, and the [automobile industry](/ap-euro/key-terms/automobile-industry "fv-autolink") is the brand-new industry it created. This is the cause-and-effect pair the CED is pointing at when it says new transportation methods created new industries (KC-3.2.IV.B).

### [Bessemer Process (Unit 6)](/ap-euro/key-terms/bessemer-process)

Cheap, mass-produced steel from the [Bessemer process](/ap-euro/key-terms/bessemer-process "fv-autolink") gave engineers the strong, affordable metal needed to build engines, cars, and machinery at scale. Second Industrial Revolution technologies fed each other, and the MCQ writers love testing them as a cluster.

### [Consumer Culture (Unit 6)](/ap-euro/key-terms/consumer-culture)

Better engines meant faster, cheaper distribution of goods, which fed the rise of department stores and mass consumerism. The engine is a transportation innovation, but its downstream effect is a social one, exactly the tech-to-society link objective 6.3.A asks for.

## On the AP Exam

On the multiple-choice section, the internal combustion engine shows up as a classic identification target. A stem might ask which innovation characterized the Second Industrial Revolution, and the engine (along with electricity, steel, and chemicals) is a correct answer while steam power and textile machinery point to the earlier revolution. Practice questions in this style also ask how the shift from steam to electricity and internal combustion engines between 1870 and 1914 spurred new consumer industries and helped industrialization spread geographically across Europe. No released FRQ has used this term verbatim, but it works as concrete evidence in any LEQ or DBQ on industrialization, especially one asking you to compare the first and second industrial revolutions or explain rising consumerism and economic integration before 1914. Don't just name the engine. Connect it to an effect, like the birth of the automobile industry or improved distribution of goods.

## internal combustion engine vs Steam engine

Both turn fuel into mechanical power, but they belong to different revolutions on the AP Euro timeline. The steam engine burns fuel externally to boil water and defines the First Industrial Revolution (coal, textiles, early railroads). The internal combustion engine burns fuel inside the engine itself and defines the Second Industrial Revolution (c. 1870-1914), alongside electricity. If an exam question is dated after 1870 and mentions new power sources replacing steam, it wants the internal combustion engine, not steam.

## Key Takeaways

- The internal combustion engine burns fuel inside the engine itself, making it smaller and more efficient than the external-combustion steam engine.
- Along with electricity, it replaced steam as a dominant power source during the Second Industrial Revolution (c. 1870-1914), which is the key dividing line between the two industrial revolutions on the exam.
- It created entirely new industries, most famously the automobile industry, supporting the CED point that efficient transportation created new industries and increased consumerism (KC-3.2.IV.B).
- Faster, cheaper transportation helped integrate national economies into a truly global economic network and raised urbanization levels (KC-3.1.III.B).
- Use it as evidence for AP Euro 6.3.A whenever you need to show how a technological innovation produced economic and social change between 1815 and 1914.

## FAQs

### What is the internal combustion engine in AP Euro?

It's an engine that burns fuel inside itself to produce power, and in AP Euro it's a signature innovation of the Second Industrial Revolution (c. 1870-1914). It belongs in Topic 6.3 alongside electricity, Bessemer steel, and chemicals.

### Is the internal combustion engine part of the first or second industrial revolution?

The second. The First Industrial Revolution ran on steam and coal, while the second (c. 1870-1914) introduced new power sources, including electricity and the internal combustion engine. Mixing these up is one of the most common errors on Unit 6 multiple-choice questions.

### How is the internal combustion engine different from the steam engine?

A steam engine burns fuel externally to boil water in a separate boiler, while an internal combustion engine burns fuel directly inside the engine. That made it lighter and portable enough to power automobiles, which steam engines couldn't realistically do.

### Why does the internal combustion engine matter for the AP Euro exam?

It's prime evidence for learning objective 6.3.A on how technology drove economic and social change. It created new industries like the automobile industry, improved the distribution of goods, and fed the rise of consumer culture before 1914.

### Did the internal combustion engine completely replace steam power by 1914?

No. Steam was still widely used in 1914, especially in railroads and factories. The exam point is that electricity and the internal combustion engine emerged as the new dominant power sources between roughly 1880 and 1914, marking the shift to second-wave industrialization.

## Related Study Guides

- [6.3 Second-Wave Industrialization and Its Effects](/ap-euro/unit-6/second-wave-industrialization-its-effects/study-guide/b5lPxh2BwluZk3TEHgwf)

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