Tire Markings; Tire Maintenance - Glacier A612 Owner's Manual

GVWR: The maximum permissible weight of
your vehicle, INCLUDING CARGO, ALL OPTIONS,
PASSENGERS, GASOLINE AND WATER.
USEFUL WEIGHTS:
Water – 8.328 pounds per gallon
Gasoline – 6.0 pounds per gallon
TIRES
The tires installed on your RV have been
preselected as the proper size and weight for
the type of RV built. The tag located on the
outside of the RV will show the proper tire size
for your RV. When replacing tires, make sure
these guidelines are followed:

TIRE MARKINGS

Sample tire size: LT225/75R 16 E
•
LT reflects the "Light Truck" usage.
Light truck tires are used on anything
from compact pickups to class A motor
homes.
•
225 indicates the "contact patch"
width. The contact patch is the amount
of tire surface that actually comes into
contact with the pavement. In this case
the width is 225 millimeters wide.
•
75 indicates the height to width ratio of
the tires.
•
R identifies the construction type of the
tire. R-Radial, B-Bias belted, D-Diagonal
Bias. Some tires may have a speed
designation label in front of the
construction type. Example – MR tires
are rated for use up to 81 mph. SR tires
up to 112 mph. ZR tires carry the
highest speed rating, and are safe for
speed over 150 mph. However, ZR tires
should never be installed on any motor
home or travel trailer. If no speed
rating is listed on the sidewall, the
maximum speed for light truck tires is
87 mph, and for passenger cars 105
mph.
•
16" is the rim size. This is the only
measurement made in inches.
•
E is the load range.
TIRE LOAD RATINGS
Load ratings for tires go up as the
corresponding letter changes. For example,
load range "E" tires have a heavier rating than
load range "D" tires. Load capabilities of tires
can change as the psi (air pressure) is lowered.
As much as 220 lbs. of load carry capacity is lost
per tire for each 5 psi below the recommended
inflation. This decreased load amount varies
from one tire manufacturer to the next;
therefore it is recommended that you contract
your tire manufacturer for further information
in this regard.
TIRE AIR PRESSURE
When checking air pressures, if the tire has
been driven more than 6 miles, you can add 4-6
psi to the rated maximum "cold" inflation
recommendations. For example, if the tire has
a maximum rating of 90 psi cold, you can inflate
the tire to 96 psi after being driven on. Under
inflation generates excessive heat (a tire's worst
enemy!), increases tread wear in the shoulder
area, and reduces your vehicle's fuel economy.
Never mix radial, bias belter or bias type tires.
Never mix brand names. This can adversely
affect vehicle handling and stability. Use only
the tire size that is listed on the Safety
Compliance Certification Label.

TIRE MAINTENANCE

When cleaning tires, try to use a tire-cleaning
agent. Never use any cleaner that contains
solvents. Solvents will draw oil from tires and
cause them to prematurely crack. Inspect your
tires prior to each trip, looking for bulges or
cracks in sidewalls.
When storing your RV for long periods you
should completely unload the vehicle so that a
minimum weight will be placed on the tires.
Make sure the tires are inflated to the
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