Tyres OVERVIEW Tyres of the correct type, manufacturer and dimensions, with correct cold inflation pressures are an integral part of every vehicle s design. Regular maintenance of tyres contributes not only to safety, but to the designed function of the vehicle. Road-holding, steering and braking are especially vulnerable to incorrectly pressurised, badly fitted or worn tyres. Tyres of the correct size and type, but of different make have widely varying characteristics. It is therefore recommended that Jaguar approved tyres are fitted to all wheels. A tyre recommendation placard is placed on the inside of the fuel filler flap, giving information specific to the vehicle s wheel and tyre equipment. TYRE PRESSURES The recommended tyre pressures are written on a label, inside the fuel filler flap. These tyre pressures provide optimum ride and handling characteristics for all normal operating conditions. The pressures should be checked, and correctly set each week with the tyres cold. Tyre temperatures and pressures increase when running. Deflating a warm tyre to the recommended pressure will result in under inflation which may be dangerous. A slight natural pressure loss occurs with time. If this exceeds 14 kpa (2 lbf/in², 0.14 bar, 0.14 kg/cm²) per week, the cause should be investigated and rectified. Note: It is an offence in certain countries to drive a vehicle with tyres that are not inflated in accordance with the vehicle s proper use. 233
TYRE PRESSURE MONITORING! WARNING: The Tyre Pressure Monitoring (TPM) system is NOT a substitute for manually checking tyre pressures. Tyre pressures, including the spare wheel, should be checked regularly, when cold, using an accurate pressure gauge and inflated to the correct pressure. Failure to properly maintain your pressures could increase the risk of tyre failure, with consequential loss of vehicle control and personal injury. The TPM system cannot register damage to a tyre. Regularly check the condition of your tyres. Note: 1. Non-approved accessories may interfere with the system. If this occurs, TYRE PRESSURE SYSTEM FAULT is displayed in the message centre. 2. Certain tyres may affect the performance of the TPM system. Always replace tyres in accordance with recommendations, see page 236. Wheels fitted with a TPM system can be easily visually identified by the external metal lock nut and valve (1). All Jaguar non-tpm system wheels have a rubber valve fitted (2). Vehicle speed If a vehicle is to be driven at speeds above 160 km/h (100 mph), the tyre pressures must be set to the recommended higher pressure stated on the tyre pressure label. If this is not carried out, the TPM System will display the message TYRE PRESSURES LOW FOR SPEED, the yellow warning light within the cluster and the AMBER priority warning light will be illuminated. In the event of this warning being displayed, the vehicle speed should be reduced. 234
Note: Always reset the tyres to Comfort pressures when speeds below 160 km/h (100 mph) are resumed. TPM system operation The TPM system monitors pressure of the tyres via sensors located in each wheel and a receiver located within the vehicle. Communication between sensor and receiver is via Radio Frequency (RF) signals. The tyre pressure warning comprises the TPM warning light, see page 104, the AMBER priority warning light and an associated message within the message centre, see page 110. If a warning appears one or more of your tyres is significantly under-inflated. You should stop and check your tyres as soon as possible and inflate them to the recommended pressure see page 233. If warnings re-occur frequently, the cause must be determined and rectified. Caution: When inflating tyres, care should be taken to avoid bending or damaging the TPM system valves. Always ensure correct alignment of the inflation head to the valve stem. Driving with an under-inflated tyre causes the tyre to overheat and can lead to tyre failure. Under-inflation also reduces fuel efficiency and tyre tread life and may affect the vehicle s handling and stopping ability. Your vehicle will also indicate a TPM system malfunction displaying the text message TYRE PRESSURE SYSTEM FAULT and illuminating the amber priority warning light. When a malfunction occurs, the system may not be able to detect or signal low tyre pressure as intended. TPM system malfunctions may occur for a variety of reasons which may include other radio frequency systems that could cause interference or the fitting of non-recommended tyres. Tyre pressures To correctly set the tyre pressures, see page 233. Spare tyre pressure: The full size spare tyre should be inflated to the highest pressure for the specified tyre size. If a wheel and tyre needs changing Full size spare wheel: Should it be necessary to change a wheel and tyre with the spare, the system will automatically recognise the change in wheel positions. After driving above 25 km/h (18 mph) the TPM system warning will clear within approximately five minutes. Temporary-use spare wheel: The temporary-use spare wheel does not have a sensor fitted. Therefore, should it be necessary to change a wheel and tyre with the temporary-use spare wheel the TPM system will automatically recognise the change in wheel positions. After approximately ten minutes of driving above 25 km/h (18 mph), the message centre will display the message TYRE PRESSURE SENSOR FAULT and the AMBER warning light will illuminate. 235
If a tyre requires to be changed Care must be taken when removing and refitting tyres to ensure that the tyre pressure sensor is not damaged. In order to avoid damage to the pressure sensor the tyre MUST be removed and refitted to the road wheel in a specific manner. It is recommended that you always have your tyres serviced or changed by a Jaguar Dealer/Authorised Repairer. Care must be taken to avoid contact between the bead of the tyre and the sensor during removal and refitting of the tyre, otherwise the sensor may become damaged and/or inoperable. Valve stem seal, washer, nut, valve core and cap should be replaced at every tyre change. TYRE RENEWAL When renewing tyres, it is preferable to fit a complete vehicle set. If either front or rear tyres only need to be renewed, new tyres must be fitted, as axle sets, to replace worn ones. After new tyres have been fitted the wheels need to be dynamically balanced. The radial ply tyres specified are designed to meet the high-speed performance capability of this vehicle (see Wheels and Tyres on page 249). Do not fit tyres with a different tread pattern, size or speed rating.! WARNING: A new valve stem seal, washer and nut must be fitted whenever the valve stem nut has been loosened. Sensor units and nuts must be refitted using correct torque figures and associated profile. If a sensor requires to be changed It is recommended that if the sensor requires replacing, it is carried out by a Jaguar Dealer/Authorised Repairer. Should the TPMS warning for any wheel not clear, even after ensuring correct inflation pressures and driving for more than ten minutes above 25 km/h (18 mph), contact your Jaguar Dealer/Authorised Repairer. Radio Frequency Approval The TPMS transmitters and receivers meet European approval. 236
Tyre wear All tyres fitted as original equipment include tread wear indicators (TWI) in their tread pattern. When the tread has worn to a remaining depth of 1.6 mm the indicators appear at the surface as bars which connect the tread pattern across the full width of the tyre. It is illegal, in certain countries, to continue to use tyres after the tread has worn to less than 1.6 mm over three quarters of the width and the entire circumference of the tyre. It should be noted that the properties of many tyres alter progressively with wear. In particular the wet grip and aquaplaning resistance are gradually but substantially reduced. Extra care and speed restriction should therefore be exercised on wet roads as the effective tread depth diminishes. Incorrect wheel alignment will accelerate tyre wear. Fins on the inner or outer edges of the tread pattern are caused by excessive toe-in or toe-out respectively. As fins may also be caused by high cornering speeds or road camber, it is advantageous to have the cause detected by having the wheel alignment checked. Tyre repair It is recommended that damaged tyres are discarded and new tyres fitted. They must not be repaired in view of the high performance capability of the vehicle. Tyre damage Excessive local distortion can cause the casing of a tyre to fracture and may lead to premature failure. Tyres should be examined especially for cracked walls, exposed cords, etc. Flints and other sharp objects must be removed from the tyre tread; if left in they may work through the cover. Clean off any oil or grease contamination by using a suitable cleaner. Caution: Do not use paraffin (kerosene), because this has a detrimental effect on rubber. TYRE USE AFTER VEHICLE STORAGE After a long period of a vehicle standing, tyres may become locally distorted with a flat area. This will cause an uneven ride for a few miles until the tyres have warmed up and the flat rounds off. However, to reduce the effects of flat-spots, the tyres of a stored vehicle may be inflated to pressures not exceeding: 420 kpa (60 lbf/in², 4.2 bar, 4.3 kg/cm²). 237
WINTER (SNOW) TYRES The tyres fitted as original equipment are designed with a rubber compound, tread pattern and width specially suited for high speeds in normal road conditions, but they are less suitable during extremes of low temperatures, snow and ice. The use of winter tyres will considerably improve the vehicle s handling during these conditions. It is recommended that only Jaguar approved winter tyres are used (see page 250). Tyre directional indicators must be rotating in a clockwise direction when viewed from the right-hand side of the vehicle, and anti-clockwise when viewed from the left-hand side of the vehicle. Do not exceed the tyre speed rating when using winter tyres. Winter tyres must be used in vehicle sets, that is, fitted on all four wheels. SNOW CHAINS Snow chains, of the recommended type, may only be fitted to rear wheels. Contact your Jaguar Dealer/Authorised Repairer for details and availability of approved snow chains. The maximum speed when using snow chains is 48 km/h (30 mph). Remove the snow chains immediately the roads are clear of snow. Ensure the fitting instructions supplied with the snow chains are kept in a safe place, for example, with this literature pack. Note: Dynamic Stability Control MUST be switched OFF when using snow chains. Tyres 238