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: Dsc system inspection
Preparation
1. Verify that the battery is fully charged.
2. With ignition switch on, verify that the ABS warning light goes out after
2.4 seconds.
3. Turn the ignition switch off.
4. On level ground, jack up the vehicle and support it evenly on safety
stands.
5. Shift the transaxle to N posi ...
Mazda 6 Owners Manual: No.5 tcs off light does not illuminate with ignition switch on
Diagnostic procedure
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunction. If there
is a problem, check to make sure co ...