Once every six months, or every 15,000 km.
Tire valve
1 and 2 - rubber and metal caps
3 - valve
4 - valve body
Examination
1. BMW, depending on the model and equipment, may have tires and wheels of various sizes. All discs have a pressing depth of 45 mm. The pressing depth is the distance from the center of the rim to the wheel stop on the brake disc or drum.
The wheel bolts for steel and alloy wheels are the same size.
Technology is constantly evolving. It may be that older models may have different tire pressures. The dimensions specified in the documents for the car are decisive.
2. With a sporty driving style, it is recommended to increase the pressure in the front and rear tires by 0.2 bar. When increasing the pressure, the base value for the various load conditions must be taken into account.
3. Winter tires typically have 0.2 bar higher pressure than summer tires. The recommendations of the winter tire manufacturers must be observed.
4. Since winter tires have a speed limit, a sign indicating the maximum speed must be fixed in the driver's field of vision.
Disc designation
Example: 6 J x 15:
6 rim width in inches.
J letter designation of the height and contour of the side flange of the rim.
X designation for a one-piece deep rim.
15 disc diameter in inches.
BMW can be equipped with tires and wheels of various sizes. However, only discs with a pressing depth of 45 mm can be used. The pressing depth is the distance from the center of the rim to the wheel stop on the brake disc or drum.
Permissible lateral runout at the rim flange: 1.2 mm.
Permissible vertical runout on the landing flange of the rim: 0.8 mm.
Tire designation
Example: 195/70 R14 89H
195 tire width in mm.
/70 height to width ratio (tire cross-sectional height is 70% of the width).
If there is no separate information about the ratio of width to height (e.g. 175 R 14), which means it is about "normal" relation. It is 82%.
R radial design.
14 rim size in inches.
89 payload parameter.
H speed class, H: up to 210 km/h (on new tires is not always given).
The speed letter is behind the tire size. Speed symbols apply to both summer and winter tyres, refer to Specifications.
Tire manufacturing date
The date of manufacture of the tire is indicated on the tire in the manufacturer's code
Example: DOT CUL2 UM8 019 TUBELESS
DOT Departament of Transporation (US Department of Transportation).
CU abbreviation of manufacturer's name.
L2 tire size.
UM8 tire performance.
01 date of manufacture - 01st working week of 1999.
TUBELESS tubeless (TUBETYPE - tube tire).
5. Regularly checking the condition of your tires will help you avoid the hassle of stopping on the road due to a flat tire. In addition, such checks provide valuable information about possible problems with the steering and suspension before serious damage appears in them.
6. Tires are equipped with built-in tread wear indicator strips, which are exposed when the tread depth drops to 1.6 mm, after which the tires are considered worn. This value represents the minimum allowable tread depth; In most cases, it is recommended to replace tires with a tread depth of 2 mm or less. Tread depth can also be determined using a simple and inexpensive device known as a tread depth gauge.
7. Pay attention to any unusual wear on the treads. Tread defects such as caverns, bulges, flattening and more severe wear on one side indicate misalignment of the front wheels and/or wheel balance. If any of the listed defects are detected, you should contact the tire shop for their correction.
8. Carefully check the tire for cuts, punctures, and stuck nails or buttons. Sometimes, after piercing a tire with a nail, it holds pressure for some time or deflates very slowly.
If there is a suspicion that such "slow puncture" first check the tightness of the inflation valve nipple. Then inspect the tread for the presence of stuck foreign objects in it or previously sealed punctures that have begun to let air through again. If there is a suspicion that there is a puncture, you can verify its presence by wetting the suspected area with soapy water. If there is a leak, the solution will begin to bubble. If the puncture is not too big, the tire can usually be repaired at any tire shop.
9. Carefully inspect the inner sidewalls of the tires for signs of brake fluid leakage. If any, check the brake system immediately.
10. Maintaining the correct tire pressure increases tire life, helps save fuel and improves driving comfort. A pressure gauge is required to check the pressure.
Always keep an accurate pressure gauge in your glove box. Pressure gauges built into the nozzles of air hoses at service stations are often inaccurate.
11. Always check the pressure on cold tires (those. before driving). If you check the pressure on warm or hot tires, this will lead to an overestimation of the pressure gauge due to the thermal expansion of the tires. In this case, the pressure should never be released, as after the tire cools down, it will be below normal.
12. Unscrew the protective cap from the inflation valve protruding from the wheel disk or from the hub cap, then firmly press the manometer nozzle onto the valve. Read the instrument readings and compare them with those recommended in the Specifications. Remember to replace the protective cap to prevent dirt and moisture from entering the nipple mechanism. Check the pressure in all four tires and, if necessary, inflate them to the recommended pressure.
13. Do not forget to maintain the required pressure in the spare wheel.
Tire pressure check
14. Checking the air pressure should only be done on cold tires.
15. Unscrew the valve cap.
16. Tire pressure is checked once a month, as well as during maintenance (including spare wheel).
17. In addition, air pressures must be checked before every long trip, as in this case, the temperature load on the tires increases.
18. The required air pressure in the tires is given on the sticker located on the inside of the fuel tank cap.
When using winter tires, the air pressure must be increased by 0.2 bar in relation to the set value.
19. The air pressure of narrow spare tires is indicated on the sidewall of the rim.
20. Car can be equipped tire pressure monitoring system (RDC - Reifen-Druck-Control). The system monitors the air pressure, both at a stationary vehicle and while driving, and takes into account the speed and outside temperature. To do this, each wheel, including the spare, has a transmission unit with a pressure and temperature sensor, which is powered by a lithium battery with a five-year service life. The transmitter transmits the signal to the receiving antenna in the wheel arch, which is connected to the onboard processor. Due to the presence of the RDC, in particular, dangerous tire ruptures which occur due to the tire deformation work as a consequence of low air pressure can be avoided.
Tire valve check
The valve extensions used must be checked for damage and contamination leading to leaks. Extension cords should be replaced if necessary.
21. Unscrew the protective cap and extension.
22. Apply a small amount of soapy water or saliva to the valve. If an air bubble forms, tighten insert 3 with protective cap 2.
To tighten the valve, use only the protective cap 2. 1 rubber protective cap, 4 valve.
23. Check the valve again. If bubbles appear and the valve cannot be tightened, it must be replaced (service station work).
24. Be sure to reinstall the protective cap.
Examples of typical tire tread wear
Lateral wear
Insufficient tire pressure causes the tire to overheat while driving due to excessive deflection, resulting in the tread not pressing sufficiently against the road surface. This results in loss of traction and excessive tread wear, not to mention the risk of tire failure due to overheating.
Check and adjust pressure.
Wrong camber (wear on one side) - Repair or replace suspension parts.
Too sharp turns - Slow down!
Central wear
Overpressure
Excessive tire pressure leads to accelerated wear of the central part of the tread, reduced traction, harder driving and an increased risk of fatal damage to the tire.
Check and adjust pressure.
If you have to inflate heavy duty tires to the pressure specified for this purpose in the Specifications, be sure to bleed it after that when going into normal operation.
Uneven wear
The front tires may wear unevenly as a result of misalignment of the wheel alignment. Tire angles can be checked and adjusted for a modest fee at most tire shops.
Incorrect camber or runout - Repair or replace suspension parts.
Suspension Defect - Repair or replace suspension parts.
Wheels out of balance - Balance the wheels.
Front wheel toe-in incorrectly adjusted - Adjust the front wheel alignment.