x Temperature: A, B or C
For example: Treadwear 200, Traction AA, Temperature A.
All passenger car tires must conform to Federal Safety Requirements in addition to these grades.
Treadwear
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 (Treadwear-value 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.
Traction
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 ⇒ .
Temperature
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 tires 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 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.
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.
speed fluctuations caused by taking your foot off the accelerator. Active braking and accelerating is then not necessarily required.
Calm and smooth driving
Consistency is more important than speed. The more smoothly you drive, the less fuel the vehicle consumes.
When driving on the highway or freeway, a constant, moderate speed is more efficient and economical than constantly accelerating and braking. Usually you can reach your destination just as quickly by driving at a moderate, but steady speed.
The cruise control system can assist in maintaining a uniform driving style.
Moderate use of extra electrical loads
Comfort inside the vehicle is nice and important, but it is important to use them in an environmentally conscious manner.
Some devices can increase fuel consumption when activated (examples):
x Climate control system (air conditioner): If the air conditioner has to produce starkly contrasting temperatures, it requires a large amount of energy, which is generated by the engine. The temperature in the vehicle should therefore not be extremely different from that of the outside temperature. It may be helpful to ventilate the vehicle before driving and then to drive a short distance with the windows open. After that, switch on the air conditioner with the windows closed. Keep the windows closed when driving at high speeds. Open windows increase fuel consumption.
x Switch off seat heating once it has served its purpose.
x Switch off the rear window defroster as soon as the windows are free of fog and ice.
Additional factors that increase fuel consumption (examples):
x Malfunctioning engine control.
x Driving in the mountains.
x Towing a trailer.
NOTICE
Never let the vehicle coast or roll down a hill in Neutral (N), especially when the engine is not running. The transmission will not be lubricated and will be damaged.
