Buhler 2180 - Manual (Page 177)

SECTION 2 - OPERATION
2-131
Always maintain the proper air pressure in the tire to
carry the load. Do not over inflate radial or bias ply
tires. Radial tires will work with LOWER air
pressures. Radial tires will show up to 20% sidewall
deflection or BULGE when properly inflated.
The force that enables the tires to drive the tractor
must be transmitted through the tire sidewalls. The
tires work best when all the tires on a given axle are
working at the same rate. Think of them like a shock
absorber; they must respond the same way to share
the load equally.
Factors Determining Best Tire Performance
Good Performance
Proper air pressure for the load
Proper sidewall deflection
8-15% wheel slip
Proper tire size for expected load
Less than 50% fill of liquid ballast
Maintaining equal tire pressure in all tires
on a given axle
Poor Performance
High or low air pressure
Stiff sidewalls
High or low wheel slip
Overloaded or underloaded tire
Excessive liquid calcium in a tire
Treating tires on an axle differently