What should be the average line pressure in drive at idle?

The average line pressure in drive at idle for most automatic transmissions typically falls within the range of 80 to 95 PSI. This pressure is crucial for the proper operation of the transmission, as it ensures that the clutches and bands receive adequate pressure to engage and disengage as necessary. Proper line pressure not only contributes to smooth shifting but also helps prevent slippage and wear of transmission components.

In automatic transmissions, line pressure is generated by the transmission pump and is influenced by various factors, such as engine speed, load, and the condition of the transmission itself. Generally, higher line pressures are needed as the vehicle speed increases or under heavy load, but at idle, the pressure stabilizes in the lower end of that spectrum to maintain functionality without causing unnecessary strain on the system.

The other ranges presented do not accurately reflect the average line pressure at idle. Lower values indicate insufficient pressure, which could lead to poor transmission performance, while significantly higher values could lead to excessive strain on components, potentially causing damage or premature wear. Thus, the chosen range of 80-95 PSI is the most appropriate for this situation.