Heavy Duty Technician Complete Practice Exam 2025

Question: 1 / 400

What is the purpose of using octane boosters in SI engines?

To increase fuel economy

To enhance octane rating

The purpose of using octane boosters in spark ignition (SI) engines is primarily to enhance the octane rating of the fuel. Higher octane ratings allow the engine to operate more efficiently under higher compression ratios and can help prevent engine knocking or pinging, which occurs when the fuel-air mixture detonates prematurely. By improving the fuel's octane rating, octane boosters allow for a more controlled and stable combustion process, ultimately leading to better engine performance.

While increasing fuel economy, improving ignition timing, and reducing emissions can be secondary benefits in some cases, the main function of octane boosters is to raise the octane level of the fuel. This allows the engine to perform optimally and can lead to enhanced power output and efficiency, especially in high-performance or modified engines designed to run on higher octane fuel.

Get further explanation with Examzify DeepDiveBeta

To improve ignition timing

To reduce emissions

Next Question

Report this question

Download Heavy Duty Technician Complete Practice Exam 2025 PDF Study Guide
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy