Attention! On S420 and S500 models, tires with a summer tread pattern may only be used on light alloy rims, tires with a winter tread pattern on light alloy and steel rims.
Depending on the model and equipment, tires and wheels of various sizes can be fitted. The discs have a pressing depth of 38 mm. The pressing depth is the distance from the middle of the disc to the wheel stop on the brake disc or drum. The wheel bolts for steel and alloy wheels are the same size.
Note. When installing alloy wheels from other manufacturers, bolts of different sizes may be required.
Technique is improving. It may be that older models may have different tire pressures. The dimensions specified in the documents for the car are decisive.
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.
Winter tires typically have 0.2 bar higher pressure than summer tires. The recommendations of the winter tire manufacturers must be observed.
Since winter tires have a speed limit, a sign indicating the maximum speed must be affixed in the driver's field of vision.
Drive designations
Example 6Jx15
Wheel width in inches | 6 |
The letter designation of the height and contour of the side flange of the rim of the disc | J |
Solid deep disk designation | x |
Disc diameter in inches | 15 |
Permissible lateral runout on the side edge of the disk: | 0.8mm |
Permissible radial runout on the landing flange of the disk: | 0.5mm |
Tire designation
Example: 195/70 R 14 89 H
Tire width in mm | 195 |
Height to width ratio (tire cross-sectional height is 70% of the width) | 70 |
Speed class, H: up to 210 km/h (on new tires is not always given). | H |
Radial design | R |
Disc size in inches | 14 |
Load parameter | 89 |
Note. 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%.
Note. If between data 14 and 89 there is the designation M + S, we are talking about tires with a winter tread.
Designation of permissible maximum speed | H |
Note. The speed symbols apply to both summer and winter tyres. Letter designations of speed are given in Specifications.
Tire manufacturing date
The date of manufacture is stamped on the tire in the manufacturer's code
Example: DOT CUL2 UM8 019 TUBELESS
DOT | Department of Transportation (US Department of Transportation) |
CU | manufacturer's name abbreviation |
L2 | tire size |
UM8 | bus version |
4600 | date of manufacture - 46th working week of 2000 |
TUBELESS | tubeless (TUBETYPE - tube tire) |
Checking the condition of your tires regularly 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.
The tires are equipped with integrated tread wear indicator strips that 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.
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.
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.
Carefully inspect the inner sidewalls of the tires for signs of brake fluid leakage. If any, check the brake system immediately.
Maintaining the correct tire pressure increases tire life, helps save fuel and improves overall driving comfort. A pressure gauge is required to check the pressure.
Recommendations
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.
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.
Unscrew the protective cap from the inflation valve protruding from the wheel disk or from the hub cap, then firmly press the pressure gauge nozzle onto the valve. Read the readings of the device and compare them with those recommended in 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.
Do not forget to maintain the required pressure in the spare wheel.
Tire pressure check
Note. Air pressure should only be checked with cold tires.
Unscrew the valve cap.
The air pressure in the tires is checked once a month, as well as during maintenance (including spare wheel). When checking, use a special pressure gauge, or a pressure gauge built into the compressor.
Note. You should not trust the readings of pressure gauges built into the nozzles of compressors used to inflate tires at gas stations.
In addition, the air pressures must be checked before every long trip, as in this case, the temperature load on the tires increases.
The required air pressure in the tires is indicated on the sticker located on the inside of the fuel tank cap.
Note. When using winter tires, the air pressure must be increased by 0.2 bar in relation to the set value.
The air pressure of narrow spare tires is indicated on the sidewall of the rim. The air pressure in the tires varies depending on the change in ambient temperature by 10°C by approximately 0.1 bar. This should be taken into account when monitoring tire pressure indoors, especially during the cold season.
Example:
The temperature in the garage | About + 20°С |
Outside temperature | Around 0°C |
Adjustable tire pressure | Prescribed value, + 0.2 bar |
Note. The tire pressure values given for a light vehicle load are the minimum values for driving comfort. The increased air pressure in the tires, which is provided for with an increased load on the car, has a positive effect on the handling of the car even at a light load and is quite acceptable. The smoothness of rolling, however, is somewhat reduced.
Tire valve check
Note. The valve extensions used must be checked for damage and contamination leading to leaks. Extension cords should be replaced if necessary.
Unscrew the protective cap and extension.
Tire valve
1 and 2 - Rubber and metal caps
3 - Valve
4 - valve body
Apply a small amount of soapy water or saliva to the faucet. If an air bubble forms, tighten the insert (3), - use the protrusion of the metal protective cap (2).
Check the valve again. If bubbles appear and the valve cannot be tightened, it must be replaced (service station work).
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
Reduce your speed!
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 had to inflate tires for transporting heavy loads to the specified for this purpose in Specifications pressure values, do not forget to bleed it afterwards when returning to normal operation.
Uneven wear
The front tires may wear unevenly as a result of misalignment of the wheel alignment.
Incorrect camber or runout
Repair or replace suspension parts.
Suspension defect
Repair or replace suspension parts.
Wheels out of balance
Perform wheel balancing.
Front wheel alignment incorrectly set
Adjust the angles of the front wheels.
Note. Fraying on the edges of the tread pattern, which is a sign of wear, is best detected by touch
Wheel rotation
Note. Wheel rotation is allowed only if the size of the front and rear wheels is the same
Rotate the wheels depending on tire wear every 5000-10000 km. At the same time, make sure that the direction of rotation of the wheels is maintained (for directional tires).
Rotation must be done before the characteristic signs of tire wear appear. A characteristic sign of wear for front wheel tires is the wear of the shoulder area of the tread, and for rear wheel tires - the middle of the tread.
With each rotation of the wheels, it is necessary to thoroughly clean them from the inside. After rotating the wheels, check and, if necessary, correct the air pressure in the tires (see above).
The wheel bolts may loosen if they are not tightened to the specified Specifications tightening torque. After changing the wheels, check the tightening torque.
Use only branded mounting bolts «MB», marked with a star «Mercedes-Benz». Other bolts may loosen.
Lightweight spare wheel
If a tire is damaged, the lightweight spare wheel can be used as a normal wheel; it is recommended, however, to replace it with a normal wheel as soon as possible, as it is designed for a limited run of up to 20,000 km.
When changing tires, the spare wheel tire can be mounted on the impeller if the tire matches the design of the impeller tyres. If the tire is older than 6 years, it is recommended to use it only if the tire is damaged.
Models with 245/45R18 tires
Attention! If a lightweight spare wheel is fitted, a change in the vehicle's dynamic properties must be taken into account due to the different tire sizes. Adapt your driving style to the traffic situation.
Replace the lightweight spare wheel with a regular wheel as soon as possible.
Models with AMG equipment
Warning! There is a danger of an accident! If a light-weight spare wheel is fitted, a change in vehicle dynamics must be taken into account due to the different tire sizes. Adapt your driving style to the situation.
The lightweight spare wheel is intended for short-term use only, subject to the prescribed tire pressure and a maximum speed of 80 km/h.
Operation with more than one lightweight spare wheel is not permitted.
Wheel replacement
Attention! Forged steel rims, 15-hole and 6-hole light alloy rims (7 Ѕ Jx16). When changing tires, the spare wheel can be used as a working one if the tire is new and the design of the wheel and tire matches the design of the working wheels and tires.
See Section Jacking and towing in Administered to this guide.
Wheel bolts
Replace wheel bolts that are damaged or rusty.
Do not lubricate the bolts with oil or grease.
If the thread in the wheel hub is damaged, you cannot continue driving. Need to go to service station «Mercedes-Benz».
Clean the contact surface of the wheel and hub.
Use only branded mounting bolts «MB», marked with a three-pointed star «Mercedes-Benz». Other bolts may loosen. Tighten the bolts to the prescribed torque (150 Nm).