How can I reduce the fuel consumption of my Mazda6?

Take it easy, don't be too intense.

If I don't drive, it drops, haha. I'm basically around 9.2, which is still acceptable.

Check the spark plugs, upstream oxygen sensor, and charcoal canister solenoid. Remember to use low viscosity oil like 0W-30 or 5W-30. Don't listen to those who say older cars with poor sealing should only use high viscosity oil like 10W-40 or 5W-40. Don't believe that! High viscosity oil increases engine resistance, which is why fuel consumption is high. The original engine's certified oil specification is 5W-30. 😄

If the driving environment is congested, fuel consumption is around 12, and it cannot be reduced.

Fuel additives can help clean carbon deposits. Replace the air filter and cabin air filter every 10,000 kilometers. Don't skimp on this expense, and use better quality engine oil.