50 • Section 2 — Driving & Safety Cayman 2006
Tire Pressure:
A motorhome may weigh slightly heavier on one side. Tire infl ation pressure of the heavier side tires
determine the infl ation pressure for all tire(s) on that axle due to the weight transfer that occurs when cornering.
Improperly infl ated tires, or an incorrectly loaded suspension, can result in poor fuel economy, poor handling
and over-stressed chassis components. How the motorhome is loaded will infl uence tire infl ation pressure and the
load carried by each axle. This is why each wheel position must be weighed. Motorhome axle confi guration and
fl oor plan styles will require different weighing procedures.
NOTE:
When weighing a motorhome, each tire on any axle must be inflated to the same pressure.
The wheel position carrying the most weight will determine the tire inflation pressure for
each tire of that particular axle.
Scales:
Certifi ed public scales are located in moving and storage lots, farm supplies with grain elevators, gravel pits,
recycling companies and large commercial truck stops. To locate a nearby public scale access, check the local
area telephone book yellow pages under Scales-Public or Weighers. A nominal fee may be charged, but this is
money wisely spent.
Weight scale types and weighing methods determine the procedure used to calculate proper tire infl ation
pressure and axle loading. Several types of scales are in use today. A platform scale will allow the entire
motorhome to fi t on the scale to read the GVW in one scale recording. A segmented platform scale is designed to
weight one axle at a time. A single axle scale weighs one axle at a time. Some scales read only one wheel position
at a time due to physical size. Several scale readings may be required to determine the GAW or GVW total.
Each wheel position requires weighing, referred to as a four-point weigh, to accurately determine the correct tire
infl ation pressure.
NOTE:
Four-point weighing is the most accurate method to determine proper tire pressure. Each
wheel position must be weighed independently. Weighing the entire axle will not accurately
determine the total weight carried by that wheel position. When calculating the drive axle
dual tire pressure using a independent corner weigh method, divide the total weight by two
to determine the weight carried by each tire. Each wheel position must be weighed and
recorded.
When weighing, the scales and the motorhome must be level to obtain an accurate scale reading. Even when
an axle is not physically on the scale, a defi nite lean in the motorhome will produce inaccurate scale readings.
To Next Page
Loading...
