Determining the appropriate tire pressure for agricultural vehicles cannot be based solely on intuition; it requires a comprehensive assessment combining precise measurement, visual inspection, and operational performance. The core standard is: under cold tire conditions, the measured value should match the standard value specified in the vehicle manual for the operational/transportation scenario, and the pressure difference between the left and right tires should be less than 20 kPa.

1. The Most Accurate Method: Using a Tire Pressure Gauge

This is the only method to obtain an accurate value, and the following guidelines must be followed:

Measurement must be performed under cold conditions: the vehicle must have been parked for at least 3 hours or driven no more than 2 kilometers. Driving will cause the tires to heat up, resulting in an inflated reading; releasing air will lead to insufficient pressure when the tires are cold.

Operating Steps:

Unscrew the valve cap and press the tire pressure gauge firmly against the valve stem.

Read the value (units are usually kPa, Bar, or kg/cm2).

Compare to the Standard: Refer to the user manual for this agricultural machinery model. If a manual is unavailable, refer to general standards: Driving wheels typically operate at 80-120 kPa during tillage, and 140-190 kPa during transport.

Note unit conversion: 1 Bar ≈ 100 kPa ≈ 1.02 kg/cm2

2. Quick Visual Inspection: Observe the Tread Blocks

Without tools, a rough judgment can be made by observing the contact area between the tire and the ground:

Normal tire pressure: Approximately 3 to 4 tread blocks are in contact with the ground, and the tire appears full and rounded.

Underinflated tire pressure: More than 4 tread blocks are in contact, the tire sidewall appears flat, and the rim may even be close to the ground. This leads to high rolling resistance, high fuel consumption, and rapid shoulder wear.

Overinflated tire pressure: The contact area is significantly reduced, and the center of the tire bulges considerably. This leads to decreased grip, increased slippage, and accelerated wear in the center of the tread.

3. Dynamic Experience Method: Observing Driving Conditions

During operation or driving, abnormal tire pressure will directly affect vehicle performance:

Signs of Insufficient Tire Pressure:

* Slow acceleration, feeling sluggish.

* Abnormally strong bumps when driving over uneven roads, with reduced cushioning.

* Heavy steering, reduced handling agility.

* Tire friction noise is louder than usual.

Signs of Excessive Tire Pressure:

* Noticeable bouncing when driving on hard roads, poor stability, prone to skidding.

* Tires are highly susceptible to blowouts or punctures when encountering obstacles.

* Driving comfort is significantly reduced, with vibrations directly transmitted to the cab.

4. Utilizing Onboard Monitoring Systems

Modern large tractors or harvesters are often equipped with tire pressure monitoring systems:

* Direct Type: The instrument panel directly displays the real-time tire pressure values, the most intuitive and reliable.

* Indirect Type: Monitors engine speed via ABS sensors. If an abnormal tire pressure causes a change in tire radius, the system will illuminate a warning light, but will not display the specific value, requiring immediate stopping and manual inspection.