For an ASM test on a vehicle with a 4-speed manual transmission, which gear should be selected?

• A. First
• B. Second
• C. Third
• D. Fourth

Answer: (B)

During an ASM test, you want the engine to be under a realistic loading condition while staying in a safe, usable RPM range. Second gear provides that balance on a four-speed manual: it gives enough torque to avoid lugging the engine at the test speed, while keeping RPM in the middle range so the exhaust readings are stable and representative. First gear would push the engine into too low an RPM and risk stalling or excessive load on the drivetrain. Higher gears like third or fourth generally don’t load the engine enough at the same speed, which can lead to rpm being too high or the test not staying within the intended operating window. So, second gear is the best choice to meet the test’s loading and RPM requirements.