Grand Design Momentum, Owner'S Manual

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Pre-Travel Information
Tire Size
To maintain tire safety, purchase new tires that are the same
size as the vehicle’s original tires or another size recommended
by the manufacturer. Look at the Tire and Loading Information
label, or the sidewall of the tire you are replacing to find this
information. If you have any doubt about the correct size to
choose, consult with the tire dealer
Tire Size & Type Designation
For example the tires on your unit may be marked with a des-
ignation of standard trailer (ST) 225/75R15 or light truck (LT)
235/85R16. The designation breakdown is as follows:
• The first three-digit number gives the width in millimeters
of the tire from sidewall edge to sidewall edge. In general,
the larger the number, the wider the tire.
• The next two-digit number after the “slash” mark, known
as the aspect ratio, gives the tire’s ratio of height to width.
• R - The “R” stands for radial.
• The last two-digit number is the wheel or rim diameter in
inches.
Maximum Permissible Inflation Pressure
This number is the greatest amount of air pressure that should
ever be put in the tire under normal driving conditions.
Speed Rating
• Typically tires with a ST designation are speed restricted
to 65 mph under normal inflation and load conditions.
• Typically tires with a LT designation are speed restricted
to 75 mph under normal inflation and load conditions. Do
not exceed these speed ratings regardless of the posted
maximum speed limit.
Tires are warranted by the tire manufacturer,
not by Grand Design RV.
If you need tire warranty assistance, please contact your dealer
or refer to the tire warranty pamphlets provided with your RV.
Because tires are
designed to be
used on more than
one type of vehicle,
tire manufacturers list the
“maximum permissible
inflation pressure” on the
tire sidewall. This number
is the greatest amount of
air pressure that should
ever be put in the tire under
normal driving conditions.