Car Engine Map

What is a Car Engine Map?

A car engine map is a graphical representation of the relationship between the air-fuel ratio (AFR) and the spark timing. It is used to determine the optimal settings for the engine to achieve the best performance and fuel economy.

How to Read a Car Engine Map

A car engine map is typically divided into two sections: the lean side and the rich side. The lean side is located at the bottom of the map, and the rich side is located at the top. The AFR is represented on the x-axis, and the spark timing is represented on the y-axis.

The optimal AFR for a car engine is typically between 14.7:1 and 15.2:1. This is known as the stoichiometric AFR. Running the engine at a leaner AFR will result in better fuel economy, but it can also lead to engine damage. Running the engine at a richer AFR will result in more power, but it can also lead to decreased fuel economy and increased emissions.

The optimal spark timing for a car engine will vary depending on the engine design. However, a general rule of thumb is to advance the spark timing as the AFR becomes leaner. This will help to prevent engine knock.

How to Use a Car Engine Map

A car engine map can be used to determine the optimal settings for the engine to achieve the best performance and fuel economy. To do this, you will need to know the following information:

The engine displacement
The engine compression ratio
The fuel type
The target AFR

Once you have this information, you can use a car engine map to determine the optimal spark timing for the engine. You can then adjust the spark timing accordingly.