Upshifting
For normal acceleration, Mazda recommends these shift points:

For cruising, Mazda recommends these shift points:

Downshifting
When you must slow down in heavy traffic or on a steep upgrade
, downshift before the engine starts to overwork. This reduces the chance of stalling and gives better acceleration when you need more speed. On a steep downgrade
, downshifting helps maintain safe speed and prolongs brake life.
Gear Shift Indicator (GSI)Mazda 6 Owners Manual: Vehicle speedometer sensor (vss) inspection
Visual Inspection
1. Remove the VSS. (See VEHICLE SPEEDOMETER SENSOR (VSS)
REMOVAL/INSTALLATION.)
2. Make sure that the sensor is free of any metallic shavings or particles.
If any are found on the sensor, clean them off.
3. Install the VSS. (See VEHICLE SPEEDOMETER SENSOR (VSS)
REMOVAL ...
Mazda 6 Owners Manual: Multi-Information Display and INFO Switch (Some models)
The multi-information display indicates the following information.
Odometer
Trip meter
Engine coolant temperature gauge
Fuel gauge
Outside temperature
Distance-to-empty
Average fuel economy
Current fuel economy
Maintenance Monitor
...