內燃機

內燃引擎的運作方式是將燃料中所含的化學能轉換為動能、透過機械或電力傳動設備傳遞至車輪、進而推動車輛。引擎所需的燃料通常儲存在車輛搭載的油箱中。此類車輛也需要滑油來潤滑機械系統，其也儲存在車輛上。兩種資源的存量都可以透過通常位於駕駛室中的儀表進行監控。上述的兩種油料都需要定期補充。

The fuel needed to run a vehicle with an internal combustion engine is typically stored in fuel tanks carried onboard. Such vehicles also carry and use oil to lubricate the mechanical systems, including the engine. The level of both resources can be monitored by gauges, usually found in the vehicle's cab , and they both need to be periodically refilled .

要發動引擎，通常有一個標註「啟動馬達」的控制裝置，用來使啟動馬達作動。這是一具小型馬達，用來轉動引擎，直到引擎開始開始燃燒燃料且自行運轉。標註「啟動馬達」的斷路器也必須開啟才能使其運作。

Each engine start creates some wear on it , and so does mere running. This is normal, due to wear and tear of the moving parts. It is generally less economical to frequently turn the engine on and off, than to keep it idling for short periods of time.

Rotational speed of an internal combustion engine, measured in rotations per minute (RPM), is controlled by throttle . Throttle position sets the desired engine RPM, while a device called the governor automatically adjusts fuel injection in order to achieve that goal. With variations in engine load, the fuel consumption will vary, regardless of the RPM it's running at.

引擎有著額定的工作轉速範圍。最低轉速是引擎能夠維持怠速、自行運轉的底線。任何更低的轉速會導致燃燒率不足使引擎熄火。最高轉速由轉速表上的紅線表示，在過度使用油門或變速箱操作不當時會使引擎超越最高轉速運轉。當轉速超越紅線時將導致引擎受損，且有機會使它徹底失效。

Internal combustion engines have a specific RPM at which they produce peak power output. Below and above that RPM, the power output diminishes. The peak power output is usually slightly below the maximum RPM. It is generally most efficient to run engines at high RPM when accelerating or engine braking , and at low RPM when coasting.

要使引擎熄火，通常有一個標註「燃油關斷」的控制裝置。這會切斷引擎的燃料供應，使其停止運轉。

由於配有引擎的車輛上載有燃料，因此若暴露在火焰之中，它們可能會爆炸。它們還會向大氣排放有害物質顆粒，僅是進行怠速就會對環境造成破壞。

Internal combustion engines in vehicles can drive drivetrains directly, such as with diesel-mechanical and diesel-hydraulic powertrains, or they can drive generators that produce electrical power, as is the case with diesel-electric powertrains.