Safari motorhome TREK 2005, Instructions Manual

Page: 68 / 330

68 • Section 2 --- Driving & Safety TREK 2005
Tire Pressure:
A motorhome may weigh slightly heavier on one side. Tire inflation pressure of the heavier side tires
determine the inflation pressure for all tire(s) on that axle due to the weight transfer that occurs when
cornering.
Improperly inflated 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 influence tire
inflation pressure and the load carried by each axle. This is why each wheel position must be weighed.
Motorhome axle configuration and floor 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:
Certified 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
inflation pressure and axle loading. Several types of scales are in use today. A platform scale will allow
the entire motorhome to fit 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 inflation pressure.
NOTE:
The most accurate method to determine proper tire pressure is four-point weighing.
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 definite lean in the motorhome will produce
inaccurate scale readings.