Upshifting
For normal acceleration and cruising, Mazda recommends these shift points:

*1 Always observe local speed limit regulations.
Downshifting
When you must slow down in heavy traffic or on a steep upgrade, downshift before the engine starts to overwork. This gives better acceleration when you need more speed.
On a steep downgrade, downshifting helps maintain safe speed and prolongs brake life.
Shift Gear (Shifting) Speed Limit
Direct ModeMazda 6 Owners Manual: Front lower arm (rear) inspection
1. Remove the lower arm (rear) from the vehicle.
2. Inspect for damage, cracks, and bending.
3. Inspect the ball joint rotation torque.
(1) Rotate the ball joint five times.
(2) Measure the rotation torque using a suitable allen socket and a
torque wrench.
If not within the specif ...
Mazda 6 Owners Manual: Air intake actuator inspection
1. Connect battery positive voltage to terminal D or F and ground to terminal
F or D of the air intake actuator.
2. Verify that the air intake actuator operates as shown below.
If not as specified, replace the air intake actuator.
...