Mercedes-Benz GLK-Class: Tire pressure

Tire pressure specifications

WARNING

Follow recommended tire inflation pressures. Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect handling and fuel economy, and are more likely to fail from being overheated.

Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are more likely to become punctured or damaged by road debris, potholes etc.

Do not overload the tires by exceeding the specified load limit as indicated on the Tire and Loading Information placard on the driver's door B-pillar. Overloading the tires can overheat them, possibly causing a blowout. Overloading the tires can also result in handling or steering problems, or brake failure.

The recommended tire pressures for the tires mounted at the factory can be found on the labels described here. Option 1) Tire and Loading Information placard on the B-pillar on the driver's side of the vehicle (). The Tire and Loading Information placard contains the recommended tire pressures for cold tires on a fully loaded vehicle and for the maximum permissible vehicle speed.

The specifications given on the following Tire and Loading Information placard are examples. Tire pressure specifications are vehicle-specific and may deviate from the data shown here. The tire pressures applicable to your vehicle can be found on the Tire and Loading Information placard on your vehicle.

1 Recommended tire pressures

Option 2) Tire pressure table on the inside of the fuel filler flap.

The tire pressure table contains the recommended pressures for cold tires for various operating conditions, i.e. differing load and speed conditions.

Specifications shown in the examples of tire pressure tables are for illustration purposes only. Tire pressure specifications are vehicle-specific and may deviate from the data shown here. Tire pressure specifications applicable to your vehicle are located in your vehicle's tire pressure table.

Example: tire pressure table for all tires approved ex-works for this vehicle

If a tire size precedes a tire pressure, the tire pressure information following is only valid for that tire size. The load conditions "partially laden" and "fully laden" are defined in the table for different numbers of passengers and amounts of luggage. The actual number of seats may differ.

Example: tire pressure table with tire dimensions

Some tire pressure tables show only the rim diameters instead of the full tire size, e.g. R18. The rim diameter is part of the tire size and can be found on the tire sidewall ().

If the tire pressures have been set to the lower values for lighter loads and/or lower road speeds, the pressures should be reset to the higher values:

• if you want to drive with an increased load and/or
• if you want to drive at higher road speeds.

The tire pressures for increased loads and/or higher road speeds, shown in the tire pressure table, may have a negative effect on driving comfort.

For trailer towing, adjust the tire pressure of the rear tires to the maximum tire pressure value stated on the table inside the fuel filler flap.

Option 3) The tire pressure for the emergency/collapsible spare wheel (depending on vehicle equipment) can be found:

• printed in yellow on the rim of the emergency/collapsible spare wheel
• in the "Wheel and tire combinations" section () in this manual
• on the Tire and Loading Information placard on the B-pillar on the driver's side.

If the tire pressure is not set correctly, this can lead to an excessive build up of heat and a sudden loss of pressure.

For further information, consult a qualified specialist workshop, e.g. an authorized Mercedes-Benz Center.

Important notes on tire pressure

WARNING

Should the tire pressure drop repeatedly:

• check the tire for foreign bodies.
• check whether the wheel is losing air or the valve is leaking.
• make sure that only a valve cap approved by Mercedes-Benz is used on the tire valve.

Tire pressures that are too low have a negative effect on vehicle safety, which could lead you to cause an accident.

To test tire pressure, use a suitable tire pressure gauge. The outer appearance of a tire does not permit any reliable conclusion about the tire pressure. On vehicles equipped with the electronic tire pressure monitoring system, the tire pressure can be checked using the on-board computer.

The tire temperature and pressure increase when the vehicle is in motion. This is dependent on the driving speed and the load.

Therefore, you should only correct tire pressures when the tires are cold.

The tires are cold:

• if the vehicle has been parked without direct sunlight on the tires for at least three hours and
• if the vehicle has not been driven more than 1 mile (1.6 km).

The tire temperature changes depending on the outside temperature, the vehicle speed and the tire load. If the tire temperature changes by 18 ‡ (10 † ), the tire pressure changes by approximately 10 kPa (0.1 bar/ 1.5 psi). Take this into account when checking the pressure of warm tires and only correct the tire pressure if it is too low for the current operating conditions. If you check the tire pressure when the tires are warm, the resulting value will be higher than if the tires were cold. This is normal. Do not reduce the tire pressure to the value specified for cold tires. The tire pressure would otherwise be too low.

Observe the recommended tire pressures for cold tires

• on the Tire and Loading Information placard on the B-pillar on the driver's side,
• in the tire pressure table on the inside of the fuel filler flap,
• printed in yellow on the rim of the emergency/collapsible spare wheel (depending on vehicle equipment).

Underinflated or overinflated tires

Underinflated tires

WARNING

Follow recommended tire inflation pressures. Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect handling and fuel economy, and are more likely to fail from being overheated.

Underinflated tires can:

• wear excessively and/or unevenly
• adversely affect fuel economy
• fail from being overheated
• adversely affect handling

Overinflated tires

WARNING Follow recommended tire inflation pressures. Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are more likely to become punctured or damaged by road debris, potholes etc.

Overinflated tires can:

• adversely affect handling
• wear excessively and/or unevenly
• be more likely to become damaged
• adversely affect ride comfort
• increase stopping distance

Maximum tire pressure

WARNING

Never exceed the maximum tire inflation pressure. Follow recommended tire inflation pressures.

Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect handling and fuel economy, and are more likely to fail from being overheated.

Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are more likely to become punctured or damaged by road debris, potholes etc.

1 Maximum permitted tire pressure (example)

The actual values for tires are specific to each vehicle and may deviate from the values in the illustration.

When adjusting the tire pressures always observe the recommended tire pressure for your vehicle ().

Checking the tire pressures

Important safety notes

WARNING

Follow recommended tire inflation pressures. Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect handling and fuel economy, and are more likely to fail from being overheated.

Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are more likely to become punctured or damaged by road debris, potholes etc.

Do not overload the tires by exceeding the specified load limit as indicated on the Tire and Loading Information placard on the driver's door B-pillar. Overloading the tires can overheat them, possibly causing a blowout. Overloading the tires can also result in handling or steering problems, or brake failure.

Check the tire pressure at least once a month. Only check and correct tire pressures when the tires are cold ().

Checking tire pressure manually

To determine and set the correct tire pressure, proceed as follows:

• Remove the valve cap of the tire that is to be checked.
• Press the tire pressure gauge securely onto the valve.
• Read the tire pressure and compare it with the recommended value on the Tire and Loading Information placard on the B-pillar on the driver's side of your vehicle.
• If necessary, increase the tire pressure to the recommended value ().
• If the tire pressure is too high, release air by pressing down the metal pin in the valve using the tip of a pen, for example. Then check the tire pressure again using the tire pressure gauge.
• Screw the valve cap onto the valve.
• Repeat these steps for the other tires.

Tire pressure loss warning system (Canada only)

Important safety notes

While the vehicle is in motion, the tire pressure loss warning system monitors the set tire pressure using the rotational speed of the wheels. This enables the system to detect significant pressure loss in a tire. If the speed of rotation of a wheel changes as a result of a loss of pressure, a corresponding warning message will appear in the multifunction display.

WARNING

If the Check Tire Pressure Soon message appears in the multifunction display, one or more tires are significantly underinflated. Stop the vehicle as soon as possible and inflate the tires to the pressure specified on the vehicle's Tire and Loading Information placard or (where available) in the tire pressure table.

Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure. Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability.

Check all tires when cold, including the spare tire, at least once a month. The tires should be inflated to the recommended pressure. This information can be found:

• on the Tire and Loading Information placard on the B-pillar on the driver's side or
• in the table for the tire pressure on the inside of the fuel filler flap

WARNING

The tire pressure loss warning system does not provide a warning for wrongly selected tire inflation pressures. Always adjust tire inflation pressure according to the Tire and Loading Information placard on the driver's door B-pillar or on the tire inflation pressure label located on the inside of the fuel filler flap.

The tire pressure loss warning system does not replace regular checks of the tire inflation pressures since a gradual pressure loss in more than one tire cannot be detected by the tire pressure loss warning system.

The tire pressure loss warning system is not able to issue a warning due to a sudden dramatic loss of tire inflation pressure (e.g. tire blowout caused by a foreign object). In this case bring the vehicle to a halt by carefully applying the brakes and avoiding abrupt steering maneuvers.

The function of the tire pressure loss warning system is limited or delayed if:

• snow chains are mounted to your vehicle's tires.
• road conditions are wintry.
• you are driving on sand or gravel.
• you adopt a very sporty driving style (cornering at high speeds or driving with high rates of acceleration).
• you are towing a very heavy or large trailer.
• you are driving with a heavy load (in the vehicle or on the roof).

Restarting the tire pressure loss warning system

Restart the tire pressure loss warning system if you have:

• changed the tire pressure
• changed the wheels or tires
• mount new wheels or tires
• Before restarting, consult the Tire and Loading Information placard on the B-pillar on the driver's side or the tire pressure table on the inside of the fuel filler flap to ensure the tire pressure in all four tires is set correctly for the current operating conditions.
• Observe the notes in the section on tire pressures ().

WARNING

The tire pressure loss warning system can only give reliable warnings if you have set the correct tire pressure.

If an incorrect tire pressure is set, these incorrect values will be monitored.

A tire with insufficient pressure results in vehicle instability when driving, thus increasing the risk of an accident.

• Make sure that the SmartKey is in position 2 () in the ignition lock.
• Press the or button to select the Service menu.
• Press the or button to select Tire Pressure.
• Press the button. The Run Flat Indicator Active Press 'OK' to Restart message appears in the multifunction display.

If you wish to confirm the restart:

• Press the button. The Tire Pressure Now OK? message appears in the multifunction display.
• Press or to select Yes.
• Press the button. The Run Flat Indicator Restarted message appears in the multifunction display.

After a teach-in period, the tire pressure loss warning system will monitor the set tire pressures of all four tires.

If you wish to cancel the restart:

• Press the button.

or

• If the Tire Pressure Now OK? message appears, press or to select Cancel.
• Press the button. The tire pressure values stored at the last restart will continue to be monitored.

Tire pressure monitor (USA only)

Important safety notes

If a tire pressure monitor system is installed, the vehicle's wheels have sensors that monitor the tire pressures in all four tires. The tire pressure monitor warns you when the pressure drops in one or more of the tires. The tire pressure monitor only functions if the correct wheel electronics units are installed on all wheels.

The tire pressure monitor has a yellow warning lamp in the instrument cluster for indicating pressure loss or a malfunction. Whether the warning lamp flashes or lights up indicates whether a tire pressure is too low or the tire pressure monitoring system is malfunctioning:

• if the warning lamp is lit continuously, the tire pressure on one or more tires is significantly too low. The tire pressure monitor is not malfunctioning.
• if the warning lamp flashes for 60 seconds and then remains lit constantly, the tire pressure monitor is malfunctioning.

WARNING

Each tire, including the spare (if provided), should be checked at least once a month when cold and inflated to the pressure recommended by the vehicle manufacturer on the tire and Loading Information placard on the driver's door B-pillar or the tire pressure label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size indicated on the tire and Loading Information placard or the tire pressure label, you should determine the proper tire pressure for those tires.

As an added safety feature, your vehicle has been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires are significantly underinflated. Accordingly, when the low tire pressure telltale illuminates, you should stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure. Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability.

Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has not reached the level to trigger illumination of the TPMS low tire pressure telltale.

Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the system is not operating properly. The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately one minute and then remain continuously illuminated. This sequence will be repeated every time the vehicle is started as long as the malfunction exists.

When the malfunction indicator is illuminated, the system may not be able to detect or signal low tire pressure as intended. TPMS malfunctions may occur for a variety of reasons, including the mounting of incompatible replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning properly. Always check the TPMS malfunction telltale after replacing one or more tires or wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the TPMS to continue to function properly.

If the tire pressure monitor is malfunctioning, it may take more than 10 minutes for the tire pressure warning lamp to inform you of the malfunction by flashing for 60 seconds and then remaining lit.

When the malfunction has been rectified, the tire pressure warning lamp goes out after driving for a few minutes.

Information on tire pressures is displayed in the multifunction display. After a few minutes of driving, the current tire pressure of each tire is shown in the multifunction display.

The tire pressure values indicated by the on-board computer may differ from those measured at a gas station with a pressure gauge. The tire pressures shown by the onboard computer refer to those measured at sea level. At high altitudes, the tire pressure values indicated by a pressure gauge are higher than those shown by the on-board computer. In this case, do not reduce the tire pressures.

The operation of the tire pressure monitor can be affected by interference from radio transmitting equipment (e.g. radio headphones, two-way radios) that may be being operated in or near the vehicle.

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference, and

2. this device must accept any interference received, including interference that may cause undesired operation.

Any unauthorized modification to this device could void the user’s authority to operate the equipment.

Checking tire pressure electronically

• Make sure that the SmartKey is in position 2 () in the ignition lock.
• Press the or button on the steering wheel to select the Service menu.
• Press the or button to select Tire Pressure.
• Press the button. The current tire pressure for each wheel will be displayed in the multifunction display.

If the vehicle has been parked for longer than 20 minutes, the Tire pressures will be displayed after driving a few minutes message appears in the display.

After a teach-in period, the tire pressure monitor automatically recognizes new wheels or new sensors. If a clear allocation of the tire pressure values to the individual wheels is not possible, the Tire Pressure Monitor Active message is shown instead of the tire pressure display. The tire pressures are already being monitored.

If a spare wheel/emergency spare wheel is mounted, the system may continue to show the tire pressure of the wheel that has been removed for a few minutes. If this occurs, note that the value displayed for the position where the spare tire is mounted is not the same as the spare wheel/emergency spare wheel's current tire pressure.

Tire pressure monitor warning messages

If the tire pressure monitor detects a significant pressure loss on one or more tires, a warning message is shown in the multifunction display. A warning tone also sounds and the tire pressure warning lamp lights up in the instrument cluster. Each tire that is affected by a significant loss of pressure is highlighted with a color. If the Correct Tire Pressure message appears in the multifunction display:

• Check the tire pressure on all four wheels and correct it if necessary.

If the wheel positions on the vehicle are interchanged, the tire pressures may be displayed for the wrong positions for a short time. This is rectified after a few minutes of driving, and the tire pressures are displayed for the correct positions.

Restarting the tire pressure monitor

WARNING

It is the driver's responsibility to set the tire pressure to the recommended cold tire pressure. Underinflated tires affect the ability to steer or brake the vehicle. You might lose control over the vehicle.

When you restart the tire pressure monitor, all existing warning messages are deleted and the warning lamps go out. The monitor uses the currently set tire pressures as the reference values for monitoring.

The tire pressure monitor must be restarted when you set the tire pressure to a new value (as a result of changed drive or load characteristics, for example). The tire pressure monitor then monitors the new tire pressure values.

Restart the tire pressure monitor after you have set the tire pressure to the value recommended for the desired driving situation (). Only correct tire pressures on cold tires. Comply with the recommended tire pressures on the Tire and Loading Information placard on the B-pillar on the driver's side. Additional tire pressure values for driving at high speeds or with heavy loads can be found in the tire pressure table on the inside of the fuel filler flap.

• Make sure that the tire pressure is correct on all four wheels.
• Make sure that the SmartKey is in position 2 in the ignition lock.
• Press the or button on the steering wheel to select the Service menu.
• Press the or button to select Tire Pressure.
• Press the button. The multifunction display shows the current tire pressure of the individual tires or the Tire pressures will be displayed after driving a few minutes message.
• Press the button. The Use Current Pressures as New Reference Values message appears in the multifunction display.

If you wish to confirm the restart:

• Press the button.

The Tire Press. Monitor Restarted message appears in the multifunction display. After driving for a few minutes, the system checks whether the current tire pressures are within the specified range. The new tire pressures are then accepted as reference values and monitored.

If you wish to cancel the restart:

X Press the button.

• The tire pressure values stored at the last restart will continue to be monitored.