How to Resolve 4000 RPM at 120 km/h?

[LaJohn]

There may be an issue with the vehicle itself. For manual transmission vehicles, it is necessary to check if the clutch is slipping, while for automatic transmission vehicles, the transmission should be inspected. Generally, the following key components can be checked: Check oil pressure, fuel injectors, and spark plugs: Inspect the working condition of the oil pressure, fuel injectors, and spark plugs. Problems in these areas can cause discrepancies in the values displayed on the dashboard, where the fuel input leads to a mismatch between the speedometer data and the engine RPM, resulting in such a situation. Relationship between speed and RPM: The relationship between speed and RPM is not one-to-one but primarily depends on the transmission gear ratio. Referring to a speed-RPM gear comparison chart, it can be observed that when the transmission is in 5th gear, the RPM reaches nearly 4000 at 120 km/h; in 6th gear, the RPM is around 3000 at the same speed; and in 7th gear, the RPM exceeds 3000 well before reaching 120 km/h.