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: Combination switch removal/installation
1. Disconnect the negative battery cable.
2. Remove the driver-side air bag module. (See DRIVER-SIDE AIR BAG MODULE
REMOVAL/INSTALLATION.)
3. Remove the steering wheel. (See STEERING WHEEL AND COLUMN
REMOVAL/INSTALLATION.)
4. Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION)
5 ...
Mazda 6 Owners Manual: Steering gear and linkage inspection
Rack Inspection
1. Inspect the rack for cracking, damage, and tooth wear. Replace it as
necessary.
2. Measure the runout of the rack.
Runout
Near point A: 0.15 mm {0.006 in} max.
Near point B: 0.20 mm {0.008 in} max.
3. If not within the specification, replace the rack.
Tie-rod End ...