Initial Mileage drop

[kbalajam]

My vehicle used to give me 402 miles when i fill my tank, right after exceeding 100k, it dropped to 359 miles for full tank.
Any advise?

 

[LodeRunner]

Have you done the recommended service for that mileage interval? Usually the following might address your issue:

- Change spark plugs and wireset.
- Clean throttle body and MAF sensor.
- Change air filter.
- Fuel additive for cleaning injectors.

Just suggestions... Good luck!