In a Two Speed Idle test, which two operating states are used?

In a Two Speed Idle test, which two operating states are used?

• A. 2500 RPM and idle
• B. Idle and 3000 RPM
• C. Idle and 1500 RPM
• D. 2000 RPM and idle

Answer: (A)

Two Speed Idle tests look at emissions at two engine states: idle and a higher, standardized high-idle speed. The high-idle setting is 2500 RPM because it provides a consistent, moderate-load condition that reliably heats the catalytic converter and reveals how the engine and cat perform under more than just idle. This pairing of idle and 2500 RPM is the established protocol for California BAR testing, ensuring readings reflect both resting and light-load operation. Other speeds (like 3000, 1500, or 2000) aren’t the standard high-idle values used in this test, so they don’t fit the protocol.

Two Speed Idle tests look at emissions at two engine states: idle and a higher, standardized high-idle speed. The high-idle setting is 2500 RPM because it provides a consistent, moderate-load condition that reliably heats the catalytic converter and reveals how the engine and cat perform under more than just idle. This pairing of idle and 2500 RPM is the established protocol for California BAR testing, ensuring readings reflect both resting and light-load operation. Other speeds (like 3000, 1500, or 2000) aren’t the standard high-idle values used in this test, so they don’t fit the protocol.