What device indicates the current gear being used or suggests a shift to a higher gear?

The shift indicator is a device specifically designed to show the current gear that the vehicle is in and may also suggest when to shift to a higher or lower gear. This feature is particularly useful in vehicles with manual transmission, where the driver needs to be aware of the appropriate gear for optimal performance and fuel efficiency. In some cars, the shift indicator will illuminate or indicate a gear change when the engine speed or load indicates it’s time to shift, aiding the driver in making timely gear adjustments for better control and efficiency.

The other devices mentioned serve different functions: the odometer measures the total distance the vehicle has traveled, the speedometer displays the current speed of the vehicle, and the turn signal indicator shows whether the turn signals are activated for making turns or lane changes. None of these devices provide information about gear selection or shifting, making the shift indicator the correct choice.