ASVAB · Engine Basics and the Four-Stroke Cycle

What does a thermostat regulate in a vehicle's cooling system?

Correct answer

Engine temperature

  1. A Oil pressure
  2. B Engine temperature
  3. C Battery voltage
  4. D Fuel flow

Why this is the answer

The thermostat regulates coolant flow to maintain optimal engine operating temperature — it opens when the engine reaches operating temp to allow coolant to flow through the radiator.
Source: ASVAB AI, Cooling System

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About this topic: Engine Basics and the Four-Stroke Cycle

Engine basics cover the four-stroke cycle (intake, compression, power, exhaust), the parts that make it happen — pistons, valves, crankshaft, camshaft — and the terms used to describe engines, such as displacement and compression ratio. This is one of 21 Auto Information questions on engine basics and the four-stroke cycle, each with a full explanation on a single study page.

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