Dot Tire Quality Grading; Air Conditioning; Testing Of Readiness Codes - Honda Civic Sedan 2019 Owner's Manual

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Glossary of Tire Terminology
n
Cold Tire Pressure – The tire air pressure when the vehicle has been parked
for at least three hours or driven less than 1 mile (1.6 km).
Load Rating – The maximum load that a tire is rated to carry for a given
inflation pressure.
Maximum Inflation Pressure – The maximum tire air pressure that the tire
can hold.
Maximum Load Rating – The load rating for a tire at the maximum
permissible inflation pressure for that tire.
Recommended Inflation Pressure – The cold tire inflation pressure
recommended by the manufacturer.
Treadwear Indicators (TWI) – The projections within the principal grooves
designed to give a visual indication of the degrees of wear of the tread.

DOT Tire Quality Grading

The tires on your vehicle meet all U.S. Federal Safety Requirements. All tires are
also graded for treadwear, traction, and temperature performance according to
Department of Transportation (DOT) standards. These gradings are explained
below.
Uniform Tire Quality Grading
n
Quality grades can be found where applicable on the tire sidewall between
tread shoulder and maximum section width.
For example:
Treadwear 200
Traction AA
Temperature A
All passenger car tires must conform to Federal Safety Requirements in
addition to these grades.
Treadwear
n
The treadwear grade is a comparative rating based on the wear rate of the
tire when tested under controlled conditions on a specified government test
course. For example, a tire graded 150 would wear one and one-half (1 1/2)
times as well on the government course as a tire graded 100. The relative
performance of tires depends upon the actual conditions of their use,
however, and may depart significantly from the norm due to variations in
driving habits, service practices, and differences in road characteristics
and climate.
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Traction
n
The traction grades, from highest to lowest, are AA, A, B, and C. Those
grades represent the tire's ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor traction performance.
WARNING: The traction grade assigned to this tire is based on straight-
ahead braking traction tests, and does not include acceleration, cornering,
hydroplaning, or peak traction characteristics.
Temperature
n
The temperature grades are A (the highest), B, and C, representing the tire's
resistance to the generation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified indoor laboratory test
wheel. Sustained high temperature can cause the material of the tire to
degenerate and reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a level of performance
which all passenger car tire must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the minimum required by
law.
WARNING: The temperature grade for this tire is established for a tire that
is properly inflated and not overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination, can cause heat
buildup and possible tire failure.

Air Conditioning

To ensure proper and safe operation, the Society of Automotive Engineers
(SAEJ2845) recommends that the refrigerant system only be serviced by trained
and certified technicians.
Never repair or replace the air conditioning evaporator (cooling coil) with one
removed from a used or salvaged vehicle.
New replacement mobile air conditioning evaporators must be certified (and
labeled) as meeting SAE Standard J2842.

Testing of Readiness Codes

Your vehicle has readiness codes as part of the onboard self-diagnostic system.
Some states use these codes for testing to verify whether your vehicle's
emissions components are working properly. The codes may not be read if you
go through the testing just after the battery has gone dead or been
disconnected.
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