Tires Flashcards
Check the tires and rims for damages
Look for signs of uneven wear, bulges or cracks, or embedded objects that could cause air leaks.
What are the most common tire damages?
The most common damages to tires and rims are tears and wounds on the side of the tire and bulges on the rim edge. This causes the resilience in the tire to be reduced. The tire can break while driving, which causes accidents.
What is the correct tire dimension for this car?
Check the vehicle registration certificate, under the column “Aksler / dekk / felger”, and see that the dimensions correspond to what is written on the side of the tires.
The vehicle card states that standard tire dimensions on axles 1 and 2 are 215/65R16.
On the tire it says that the tire dimension is 215 / 55R18.
This is what the marks on the tires mean:
215 stands for tire width in millimeters.
55 is the height of the tire as a percentage of width.
R stands for radial, and explains how the tire is constructed.
18 stands for the rim diameter in inches.
99 is load class, how much weight the tire can carry.
V is speed code. This tells the limit of how fast the tire is designed to drive.
In addition, the tires are marked m · s if they are winter tires.
The vehicle registration certificate states that there are alternative tire and rim dimensions you can use on this car. This means that the tire dimensions of this car are correct.
The deviation in rolling circumference can be a maximum of + -5% in relation to the standard tire dimension stated in the vehicle registration certificate. If you choose to increase the height of the rim, you must also reduce the height of the tire (lower profile).
Where can you find the correct tire pressure for this car?
You can find the tire pressure specifications along the door jam or in the gas tank lid. You can also check your vehicle owner’s manual for tire pressure recommendations.
(Remember the picture :) )
According to the label along the door jam the right air pressure for this car is:
1-3 passengers included luggage, 260 kPa in the front tires and 240 kPa in the rear tires
4-5 passengers included luggage, 260 kPa in the front tires and 260 kPa in the rear tires
Check the tire pressure in the front wheels
Take a visual control or use a pressure gauge. If you do not have a pressure gauge they have it at the gas station. This is how you check the pressure.
Unscrew the valve cap Check current pressure - place the filling gun at the valve. You should be able to see the current air pressure in the tires. Fill to the correct level - If the air pressure is low, fill up a small amount of air at the time, until you reach the right tire pressure for your car
The cars we use for our driving lessons have tire pressure warning, which means that if the tires have the wrong air pressure, a dashboard lamp will light up.
What is the legal requirement for tire depth for winter and summer tires?
Winter tires have a minimum requirement of 3 mm (between November 1st and the second Sunday after Easter Monday) and the summer tires have a minimum requirement of 1.6mm. The tire is measured at the most worn place.
Check the tread depth on the tires
Use a tread depth gauge to measure the tread depth where the tire is most worn. Measure in three different places, such as the edges and center of the tire. Make sure there are no bumps on the tire surface.
What are the risks of driving with tread depth under the legal limit?
You get poor grip and increase the risk of aquaplaning and the braking distance increases. You also risk recourse if you are unlucky (that you have to pay back the insurance company or risk not getting coverage for the insurance).
Check the front tires for wear and tear.
Take a visual control. Can you see the tread sensors? Are the tires worn in the middle? Is there extensive wear on the edges of the tire?
What can the tire wear tell you?
It could be the wrong air pressure. If the tires are worn in the middle, it may be a sign of too high air pressure, if the tires are only worn on the sides, the tire pressure may be too low. In some cases, the wear is different on the tires. Worn shock absorbers can also cause you to experience abnormally high tire wear.
What is the minimum load index for the tires on this car?
Check the vehicle registration certificate, under “Min.LI” (Minimum Load Index). In the vehicle registration certificate it says 84 which means 500kg.
Check that all the tires have the correct load index.
The vehicle registration card in the car shows speed code U, which is a minimum equivalent to 200 km/h. On the tire we can see that it says “V” which means 240 km/h. All letters in the alphabet after the letter written in the vehicle registration card are approved tires to use. V comes after U. The tire has therefore the correct speed code.
