2018 VOLVO XC90 T8 wheel torque

DRIVER SUPPORT
* Option/accessory.273
WARNING
While the power steering is working at reduced power, the driver support functionswith steering assistance are not available. In such a situation, the driver display shows the
Power steering failure or Power
Steering Assist Temporarily Reduced
message, combined with a STEERING WHEEL symbol.
Changing the level of steering wheel resistance *
To change the level of steering wheel resistance, see the description of the INDIVIDUAL optionunder "Available drive modes" in the "Drivemodes" section. On models not equipped with drive mode con- trols and the INDIVIDUAL option, steering wheelresistance can instead be set in the center dis-play's Top view under:
SettingsMy CarDrive ModesSteering force
Steering wheel resistance settings cannot be accessed when turning at speeds above10 km/h (6 mph).
Related information
•Drive modes (p. 445)
• Pilot Assist (p. 311) •
Lane Keeping Aid (p. 364)
• Steering assistance at risk of collision(p. 372)
• Park Assist Pilot
* (p. 395)
Stability system Roll StabilityControl
The Roll Stability Control (RSC 1
) system helps
minimize the risk of a rollover in the event of e.g. a sudden evasive maneuver or if the vehiclebegins to skid.
The RSC system monitors the lateral angle at which the vehicle is leaning and registers anychanges. Using this information, the system cal-culates the likelihood of a rollover. If there is animminent risk of a rollover, Electronic StabilityControl is activated, engine torque is reduced andbrakes are applied to one or more of the wheelsuntil the vehicle has regained stability.
WARNING
The vehicle

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STARTING AND DRIVING
* Option/accessory.
438
Related information
• Rear Collision Warning (p. 347)
• BLIS
* (p. 348)
• Brake functions (p. 429)
Transmission The transmission is part of the vehicle's driveline (power transmission) between the engine andthe drive wheels. The function of the transmis-sion is to change gears depending on speedand power needs.
The vehicle has an 8-speed automatic transmis- sion and an electric motor for rear-wheel drive.The number of gears allows the engine's torqueand power band to be effectively utilized. Two ofthe gears are overdrive gears that save fuel whendriving at a constant engine speed. The steering wheel paddles
* can be used to shift up or down
manually. The instrument panel shows the gear currently in use.
CAUTION
Check the operating temperature of the transmission to help avoid damage to any ofthe drive system components. If there is a riskof overheating, a warning symbol will appearin the instrument panel and a text messagewill be displayed. Follow the recommenda-tions given.
Symbols in the instrument panelIf a problem should occur with the transmission, a symbol and a message will appear in the instru-ment panel.
SymbolMeaning
Information and messages related to the transmission. Follow the rec-ommendations provided.
Hot or overheated transmission. Follow the recommendations provi-ded.
Reduced performance/Acceler-
ation performance reduced
In the event of a temporary fault in the driveline, the vehicle may gointo a "limp home" mode withreduced power output to help avoiddamage to the driveline.
Related information
• Gear selector positions for automatic trans- missions (p. 439)
• Gear indicator
* (p. 442)

STARTING AND DRIVING
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443
All Wheel Drive (AWD)All-wheel drive, All Wheel Drive (AWD), also called four-wheel drive, means that power is dis-tributed to all four wheels, which improves trac-tion.
The electric motor that powers the rear wheels enables electronic all-wheel drive functionality. To achieve the best traction, power is automati- cally directed to the wheels that have the bestgrip. The system continuously calculates theneed for torque to the rear wheels, and canimmediately redistribute up to half of the engine'storque to the rear wheels. All-wheel drive also has a stabilizing effect at higher speeds. In normal driving conditions, mostof the engine's power is directed to the frontwheels. When the vehicle is stationary, all-wheeldrive is always activated in preparation for maxi-mum traction during acceleration. All-wheel drive reacts differently depending on which drive mode is selected.
Related information
• Drive modes (p. 445)
• Low Speed Control (p. 453)
• Transmission (p. 438)
Drive systems
Volvo Twin Engine combines a combustion engine for the front wheels and an electric motorfor the rear wheels.
Two drive systemsDepending on the selected drive mode and power available in the electric motor, the drivesystems can either be used separately or in tan-dem. The electric motor gets its energy from a hybrid battery located under the tunnel console. Thehybrid can be charged from a wall outlet or in a special charging station. The combustion engine can also charge the hybrid battery using a special high-voltage generator. Both the combustion engine and the electric motor can generate power directly to the wheels.An advanced control system coordinates both thedrive systems to help optimize driving economy.
Hybrid battery - The hybrid battery's function is to store electrical current. This energy isprovided by plugging the charging cable intoan electrical outlet, through regenerativebraking or from the high-voltage generator.This provides current to power the electricmotor and to temporarily power the electricalair conditioning to precondition the passen-ger compartment.
Combustion engine - The combustion engine starts when the charge level in the hybridbattery is too low to provide the power outputrequested by the driver.
High-voltage generator 3
- Charges the hybrid
battery. Starter for the combustion engine.
2 This illustration is generic. The layout may vary depending on vehicle model and software updates.
3 CISG (Crank Integrated Starter Generator) - Combined high-voltage generator and starter.

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STARTING AND DRIVING
444Can provide the combustion engine with extra electrical current.
Electric motor - Powers the vehicle using electricity. Can provide extra torque andpower during acceleration. Provides electricalall-wheel drive functionality. Regeneratesbraking energy into electrical current.
Related information
•
General information about Twin Engine(p. 406)
• Starting and stopping the combustion enginein Twin Engine vehicles (p. 444)
• Drive modes (p. 445)
• Transmission (p. 438)
• Factors affecting electric motor range(p. 458)
Starting and stopping thecombustion engine in Twin Enginevehicles
An advanced control system determines the dis- tance that the vehicle can be driven on the com-bustion engine, electric motor, or both at thesame time. When driving on only the electricmotor, the vehicle may automatically start thecombustion engine due to outside circumstan-ces, e.g. low ambient temperatures. This is com-pletely normal. The combustion engine will alsoalways start when the hybrid battery is nearlyfully discharged.
Climate settings at low temperaturesAt low ambient temperatures, the combustion engine will sometimes start automatically to helpachieve the desired passenger compartmenttemperature and air quality. The amount of timethe combustion engine is running can be affec-ted by:
• lowering the temperature
• reducing blower speed
• activating Pure drive mode.
Using the electric motor in hot or cold weather
At very low or high ambient temperatures, the electric motor's driving range and power may bereduced and affect how often the combustionengine automatically starts.
Emission control systemTo help ensure that the emission control systemfunctions optimally, the combustion engine willrun for several minutes after it is started. Theamount of time the combustion engine needs tobe used varies depending on the temperature ofthe three-way catalytic converter.
Related information
•
Drive systems (p. 443)
• Economical driving (p. 456)
• Using the electric motor only (p. 457)
• Drive modes (p. 445)

STARTING AND DRIVING
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447
OFF ROAD
•Maximizes the vehicle's ability to traverse dif- ficult terrain or poor roads.
In this mode, ground clearance 4
is high, steering
is light, and all-wheel drive and Hill DescentControl are activated. This drive mode is only available at low speeds, up to 40 km/h (25 mph). If this speed is excee-ded, Off road mode will be cancelled and AWDmode will be activated instead. All-wheel drive requires both the combustion and electric motor to be in continuous operation,which results in higher fuel consumption. In Off road mode, a compass will be displayed between the speedometer and the tachometer inthe instrument panel. The permissible speedrange will be shown in the speedometer. This drive mode is optimized for maximum control when driving at low speeds on very poor roads or difficult terrain. It raises the chassis 4
, reduces
driveline throttle response, and locks the vehicle in all-wheel drive. The Hill Descent Control func-tion facilitates controlled driving on steep down-grades.NOTE
This drive mode is not designed to be used for normal street driving.
NOTE
Due to the increased ground clearance, if the OFF ROAD mode was selected when theengine was switched off, the suspension willlower when the engine is restarted.
CAUTION
Do not use the OFF ROAD drive mode when towing a trailer without an electrical connec-tion. This could result in damage to the pneu-matic suspension system's bellows.
AWD
• Improves the vehicle's traction and handling by increasing all-wheel drive.
This drive mode locks the vehicle in all-wheeldrive. An optimal distribution between front andrear axle torque helps provide the best possiblecontrol, stability and traction, e.g. on slipperyroads or when towing a heavy trailer or anothervehicle. The AWD drive mode is always availableregardless of the hybrid battery's charge status. Both the combustion engine and the electricmotor are engaged to enable all-wheel drive,which results in higher fuel consumption. In the other drive modes, the vehicle automati- cally adapts the need for all-wheel drive accord-ing to the road surface, and can activate the elec-tric motor or start the combustion engine as nee-ded.
POWER
•
Power mode is designed to provide sportier driving characteristics and a faster accelera-tion response.
This drive mode maximizes the combined powerfrom the combustion engine and the electricmotor by providing power to both the front andrear wheels. Gear shifting will be faster and moredistinct and the transmission will prioritize gearswith a higher traction force. Steering response isfaster, suspension is stiffer and ground clearance is lower 4
to help reduce body roll when cornering.
Both the combustion engine and the electric motor are engaged to enable all-wheel drive,which results in higher fuel consumption. This drive mode is optimized for maximum per- formance and throttle response. It changes thethrottle response, gear shifting program andturbo boost system. Chassis settings and steer-ing and brake response are also optimized. ThePower drive mode is always available regardlessof the hybrid battery's charge status.
4 For vehicles with pneumatic suspension.

WHEELS AND TIRES
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* Option/accessory.565
Jack*
The jack can be used to lift the vehicle to e.g. change a wheel.
The illustration is generic – the design may vary.
CAUTION
• When not in use, the jack
* should be kept
in its storage compartment under the cargo compartment floor.
• The jack provided with your vehicle isintended to be used only in temporary sit-uations such as changing wheels in theevent of a flat tire. Only the jack thatcame with your particular model shouldbe used to lift the vehicle. If the vehicleneeds to be lifted more frequently or for aprolonged period, using a garage jack orhoist is recommended. Always follow thisdevice's instructions for use.
The jack needs to be cranked together to the correct position in order to fit.
Models with leveling control
*
If the vehicle is equipped with the optional pneu- matic suspension, it must be turned off beforethe vehicle is lifted on a jack.
Related information
•Tool kit (p. 564)
Wheel bolts
The wheel bolts hold the wheel in place on the wheel hub.
CAUTION
The wheel bolts should be tightened to 140 Nm (103 ft. lbs.). Over-tightening orunder-tightening could damage the threadedjoints.
Only use rims that have been tested and approved by Volvo and are included in Volvo'soriginal product range. Use a torque wrench to check that the wheel bolts are tightened correctly. Do not grease the wheel bolt threads.
WARNING
The wheel bolts may need to be tightened again several days after a wheel change.Temperature fluctuations and vibrations cancause them to loosen slightly.
Locking wheel bolts *A tool for removing the locking wheel bolts is located in the foam block under the cargo com-partment floor.

WHEELS AND TIRES
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* Option/accessory.569
1. Clean the contact surfaces between the
wheel and the wheel hub.
2. Lift the wheel into place. Tighten the wheel bolts securely. Do not grease the wheel bolt threads.
3. Lower the vehicle so that the wheel cannot rotate.
4. Tighten the wheel bolts in a crisscross pat- tern (as shown in illustration). It is important that the wheel bolts are securely tightened.Tighten to a torque of 140 Nm (103 ft.lbs.).Use a torque wrench to check torque.
5. Press the plastic covers onto the wheel bolts.
WARNING
The wheel bolts may need to be tightened again several days after a wheel change.Temperature fluctuations and vibrations cancause them to loosen slightly.
NOTE
• After inflating a tire, always replace the valve cap to help prevent valve damagecaused by gravel, dirt, etc.
• Use plastic valve caps only. Metal capscould corrode and become difficult toremove.
Related information
•
Leveling control settings
* (p. 453)
• When changing wheels (p. 564)
• Hoisting the vehicle (p. 605)
• Jack
* (p. 565)
• Tool kit (p. 564)
• Removing a wheel (p. 566)
Spare wheel11
The spare wheel is a Temporary spare and can be used to temporarily replace a punctured tireon one of the vehicle's regular wheels.
The spare tire is only intended for temporary use. Replace it with a normal wheel as soon as possi-ble. The driving characteristics of the vehicle change and ground clearance reduces when the sparewheel is used. Do not wash the vehicle in anautomatic car wash while using the TemporarySpare. The recommended tire pressure must be main- tained regardless of at which position the tempo-rary spare wheel is used on the vehicle. If the spare wheel is damaged, a new one can be purchased from a Volvo retailer.
WARNING
Current legislation prohibits the use of the "Temporary Spare" tire other than as a tem-porary replacement for a punctured tire. Itmust be replaced as soon as possible by astandard tire. Road holding and handling maybe affected with the "Temporary Spare" inuse. Do not drive faster than 80 km/h(50 mph).
11 Not available on all models.