True or False: Auto Ignition temperature in a gas engine is higher than in diesel engines.

The assertion that the auto ignition temperature in a gas engine is higher than in diesel engines is indeed true. Gasoline typically has a higher auto ignition temperature, generally ranging from about 250°C to 300°C (482°F to 572°F), while diesel fuel ignites at a lower temperature, often around 210°C to 250°C (410°F to 482°F).

This difference is primarily due to the distinct properties of the fuels used in gas and diesel engines. Gasoline is designed to vaporize and mix with air more readily, requiring a higher ignition temperature to initiate combustion when no spark is present, whereas diesel engines rely on compression to reach temperatures high enough for auto ignition.

Understanding the auto ignition characteristics of different fuels is critical for heavy-duty technicians, as it affects engine design, operational efficiency, and emissions control strategies. Recognizing these differences helps in troubleshooting and optimizing engine performance across various applications.