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: Climate control unit disassembly/assembly
1. Disassemble in the order indicated in the table.
2. Assemble in the reverse order of disassembly.
Wire Disassembly Note
Disassemble the wires in the shown in the figure.
Wire Assembly Note
Assemble the wires to the position as shown in the figure.
...
Mazda 6 Owners Manual: Driver-side air bag module removal/installation
Warning
Handling the air bag module improperly can accidentally deploy the
air bag module, which may seriously injure you. Read AIR BAG SYSTEM SERVICE
WARNINGS before handling the air bag module. (See SERVICE WARNINGS.)
Due to the adoption of 2-step deployment control in both the
driv ...