MERCEDES-BENZ GL 2016 Owner's Manual

Selecting the unit of measure-
ment .............................................. 283
see Instrument cluster
Standing lamps
Display message ............................ 305
Switching on/off ........................... 132
Start/stop function
see ECO start/stop function
Starting (engine) ................................ 167
STEER CONTROL .................................. 77
Steering (display message) .............. 322
Steering assistant STEER CON-
TROL
see STEER CONTROL
Steering wheel
Adjusting (electrically) ................... 122
Adjusting (manually) ...................... 121
Button overview ............................... 37
Buttons (on-board computer) ......... 273
Cleaning ......................................... 382
Important safety notes .................. 121
Paddle shifters ............................... 178
Steering wheel heating .................. 122
Storing settings (memory func-
tion) ............................................... 127
Steering wheel heating
Problem (malfunction) ................... 123
Switching on/off ........................... 122
Steering wheel paddle shifters ........ 178
Stopwatch (RACETIMER) ................... 288
Stowage areas ................................... 340
Stowage compartments
Armrest (under) ............................. 342
Center console .............................. 342
Center console (rear) ..................... 342
Cup holders ................................... 349
Eyeglasses compartment ............... 342
Glove box ....................................... 341
Important safety information ......... 341
Stowage net ................................... 343
Stowage net ....................................... 343
Summer tires ..................................... 406
Sun visor ............................................ 350
Surround lighting (on-board com-
puter) .................................................. 284 Suspension tuning
AMG adaptive sport suspension
system ........................................... 223
SETUP (on-board computer) .......... 287
SUV
(Sport Utility Vehicle) ....................... 27
Switching air-recirculation mode
on/off ................................................. 159
T Tachometer ........................................ 273
Tail lamps
Display message ............................ 304
Tailgate
Display message ............................ 321
Emergency unlocking ....................... 97
Important safety notes .................... 93
Limiting the opening angle ............... 96
Opening dimensions ...................... 454
Opening/closing (automatically
from inside) ...................................... 96
Opening/closing (automatically
from outside) ................................... 94
Opening/closing (from outside) ....... 94
Tank
see Fuel tank
Tank content
Fuel gauge ....................................... 35
Technical data
Capacities ...................................... 447
Emergency spare wheel ................. 441
Information .................................... 444
Tires/wheels ................................. 432
Trailer loads ................................... 458
Vehicle data ................................... 454
TELEAID
Call priority .................................... 360
Downloading destinations
(COMAND) ..................................... 360
Downloading routes ....................... 363
Emergency call .............................. 357
General notes ................................ 356
Geo fencing ................................... 364
Locating a stolen vehicle ............... 362
MB info call button ........................ 359
Remote vehicle locking .................. 362
Roadside Assistance button .......... 358 Index 19

Search & Send ............................... 361
Self-test ......................................... 357
Speed alert .................................... 364
System .......................................... 357
Triggering the vehicle alarm ........... 364
Vehicle Health Check .................... 363
Vehicle remote unlocking .............. 362
Telephone
Accepting a call ............................. 280
Display message ............................ 322
Menu (on-board computer) ............ 279
Number from the phone book ........ 280
Redialing ........................................ 280
Rejecting/ending a call ................. 280
Temperature
Coolant (display in the instrument
cluster) .......................................... 273
Coolant (on-board computer,
Mercedes-AMG vehicles) ............... 287
Engine oil (on-board computer,
Mercedes-AMG vehicles) ............... 287
Outside temperature ...................... 273
Setting (climate control) ................ 155
Transmission oil (on-board com-
puter, Mercedes-AMG vehicles) ..... 287
Through-loading feature ................... 343
Time
see separate operating instructions
Timing (RACETIMER) ......................... 288
Tire pressure
Calling up (on-board computer) ..... 412
Checking manually ........................ 411
Display message ............................ 318
Maximum ....................................... 411
Not reached (TIREFIT) .................... 390
Notes ............................................. 409
Reached (TIREFIT) .......................... 390
Recommended ............................... 408
Tire pressure loss warning system
General notes ................................ 411
Important safety notes .................. 411
Restarting ...................................... 412
Tire pressure monitor
Checking the tire pressure elec-
tronically ........................................ 414
Function/notes ............................. 412
General notes ................................ 412
Important safety notes .................. 413 Radio type approval for the tire
pressure monitor ........................... 415
Restarting ...................................... 415
Warning lamp ................................. 338
Warning message .......................... 414
TIREFIT kit .......................................... 388
Tire pressure not rea ched .............. 390
Tire p ressure reached .................... 390
Tires
Aspect ratio (definition) ................. 426
Average weight of the vehicle
occupants (definition) .................... 425
Bar (definition) ............................... 424
Changing a wheel .......................... 427
Characteristics .............................. 424
Checking ........................................ 405
Curb weight (definition) ................. 426
Definition of terms ......................... 424
Direction of rotation ...................... 427
Display message ............................ 318
Distribution of the vehicle occu-
pants (definition) ............................ 427
DOT (Department of Transporta-
tion) (definition) ............................. 425
DOT, Tire Identification Number
(TIN) ............................................... 424
GAWR (Gross Axle Weight Rating)
(definition) ..................................... 425
General notes ................................ 432
GTW (Gross Trailer Weight) (defi-
nition) ............................................ 425
GVW (Gross Vehicle Weight) (def-
inition) ........................................... 425
GVWR (Gross Vehicle Weight Rat-
ing) (definition) .............................. 425
Important safety notes .................. 404
Increased vehicle weight due to
optional equipment (definition) ...... 425
Information on driving .................... 404
Kilopascal (kPa) (definition) ........... 425
Labeling (overview) ........................ 421
Load bearing index (definition) ...... 426
Load index ..................................... 423
Load index (definition) ................... 425
M+S tires ....................................... 406
Maximum load on a tire (defini-
tion) ............................................... 42620
Index

Maximum loaded vehicle weight
(definition) .................................... .4 25
Maximum permissible tire pres-
sure (definition) ............................ .4 26
Maximum tire load ......................... 423
Maximum tire load (definition) ....... 426
MOExtended tires .......................... 406
Optional equipment weight (defi-
nition) ............................................ 426
PSI (pounds per square inch) (def-
inition) .......................................... .4 26
Replacing ....................................... 427
Service life ..................................... 406
Sidewall (definition) ....................... 426
Speed rating (definition) ................ 425
Storing .......................................... .4 27
Structure and characteristics
(definition) ..................................... 424
Temperature .................................. 420
TIN (Tire Identification Number)
(definition) ..................................... 426
Tire bead (definition) ..................... .4 26
Tire pressure (definition) ................ 426
Tire pressures (recommended) ...... 425
Tire size (data) ............................... 432
Tire size designation, load-bearing
capacity, speed rating .................... 421
Tire tread ....................................... 405
Tire tread (definition) ..................... 426
Total load limit (definition) ............. 427
Traction ......................................... 420
Traction (definition) ....................... 426
Tread wear ..................................... 420
TWR (permissible trailer drawbar
noseweight) (definition) ................. 426
Uniform Tire Quality Grading
Standards ...................................... 419
Uniform Tire Quality Grading
Standards (definition) .................... 425
Wear indicator (definition) ............. 427
Wheel and tire combination ........... 434
Wheel rim (definition) .................... 425
see Flat tire
Tool
see Vehicle tool kit
Top Tether ............................................ 64
Tow -s
tarting
Emergency engine starting ............ 400 Important safety notes .................. 397
Towing a trailer
Active Parking Assist ..................... 231
Axle load, permissible .................... 458
Cleaning the trailer tow hitch ......... 381
Coupling up a trailer ...................... 266
Decoupling a trailer ....................... 268
Driving tips .................................... 264
ESP ®
(Electronic Stability Pro-
gram) ............................................... 75
Important safety notes .................. 263
Installing the ball coupling ............. 265
Lights display message .................. 303
Mounting dimensions .................... 457
Power supply ................................. 269
Pulling away with a trailer .............. 168
Removing the ball coupling ............ 269
Trailer drive program ..................... 256
Trailer loads ................................... 458
Towing away
Important safety guidelines ........... 397
Installing the towing eye ................ 398
Removing the towing eye ............... 399
With both axles on the ground ....... 399
Trailer coupling
see Towing a trailer
Trailer loads and drawbar nose-
weights ............................................... 269
Trailer towing
Active Blind Spot Assist ................. 251
Active Lane Keeping Assist ............ 254
Blind Spot Assist ............................ 246
PARKTRONIC ................................. 226
Permissible trailer loads and
drawbar noseweights ..................... 269
Transfer case ..................................... 182
Transmission
see Automatic transmission
Transmission position display ......... 174
Transmission position display
(DIRECT SELECT lever) ...................... 174
Transporting the vehicle .................. 399
Traveling uphill
Brow of hill ..................................... 202
Driving downhill ............................. 202
Maximum gradient-climbing capa-
bili ty ............................................... 202 Index 21

Trim pieces (cleaning instruc-
tions) .................................................. 382
Trip computer (on-board com-
puter) .................................................. 276
Trip odometer
Calling up ....................................... 275
Resetting (on-board computer) ...... 277
Trunk
see Tailgate
Turn signals
Display message ............................ 304
Switching on/off ........................... 132
Two-way radio
Frequencies ................................... 444
Installation ..................................... 444
Transmission output (maximum) .... 444
TWR (Tongue Weight Rating) (defi-
nition) ................................................. 426
Type identification plate
see Vehicle identification plate
UUnlocking
Emergency unlocking ....................... 92
From inside the vehicle (central
unlocking button) ............................. 91
Upshift indicator (on-board com-
puter, Mercedes-AMG vehicles) ....... 287
V
Vanity mirror (in the sun visor) ........ 351
Vehicle
Correct use ...................................... 29
Data acquisition ............................... 30
Display message ............................ 320
Equipment ....................................... 25
Individual settings .......................... 283
Limited Warranty ............................. 30
Loading .......................................... 416
Locking (in an emergency) ............... 92
Locking (SmartKey) .......................... 82
Lowering ........................................ 431
Maintenance .................................... 26
Parking for a long period ................ 192
Pulling away ................................... 168
Raising ........................................... 429 Reporting problems ........................ .2 9
Securing from rolling away ............ 428
Towing away .................................. 397
Transporting .................................. 399
Unlocking (in an emergency) ........... 92
Unlocking (SmartKey) ...................... 82
Vehicle data ................................... 454
Vehicle battery
see Battery (vehicle)
Vehicle data ....................................... 454
Vehicle data (off-road driving)
Approach/departure angle ............ 456
Fording depth ................................ 455
Maximum gradient climbing abil-
ity .................................................. 456
Vehicle dimensions ........................... 454
Vehicle emergency locking ................ 92
Vehicle identification number
see VIN
Vehicle identification plate .............. 446
Vehicle level
AMG adaptive sport suspension
system ........................................... 222
Vehicle level (display message) ....... 310
Vehicle tool kit .................................. 386
Video
Operating the DVD ......................... 279
VIN ...................................................... 446
W
Warning and indicator lamps
ABS ................................................ 327
Brakes ........................................... 326
Check Engine ................................. 334
Coolant .......................................... 335
Distance warning ........................... 337
DISTRONIC PLUS ........................... 337
ESP ®
.............................................. 330
ESP ®
OFF ....................................... 331
Fuel tank ........................................ 334
Overview .......................................... 36
PASSENGER AIR BAG OFF ............... 45
Reserve fuel ................................... 334
Restraint system ............................ 333
Seat belt ........................................ 325
Tire pressure monitor .................... 338
Warranty .............................................. 2522
Index

Washer fluid
Display message ............................ 323
Wheel and tire combinations
Tires ............................................... 434
Wheel bolt tightening torque ........... 431
Wheel chock ...................................... 428
Wheels
Changing a wheel .......................... 427
Checking ........................................ 405
Cleaning ......................................... 379
Emergency spare wheel ................. 438
General notes ................................ 432
Important safety notes .................. 404
Information on driving .................... 404
Interchanging/changing ................ 427
Mounting a new wheel .................. .4 31
Mounting a wheel .......................... 428
Overview ........................................ 404
Removing a wheel .......................... 430
Storing .......................................... .4 27
Tightening torque ........................... 431
Wheel size/tire size ....................... 432
Window curtain air bag
Display message ............................ 300
Operation ......................................... 53
Windows
see Side windows
Windshield
Defrosting ...................................... 157
Windshield washer fluid
see Windshield washer system
Windshield washer system
Adding washer fluid ....................... 374
Notes ............................................. 453
Windshield wipers
Problem (malfunction) ................... 142
Rear window wiper ........................ 140
Replacing the wiper blades ............ 140
Switching on/off ........................... 139
Winter driving
Slippery road surfaces ................... 197
Snow chains .................................. 407
Winter operation
General notes ................................ 406
Overview ........................................ 406
Radiator cover ............................... 371
Snow drive program ....................... 255 Winter tires
M+S tires ....................................... 406
Wiper blades
Cleaning .............. ........................... 379
Important safe ty
notes .................. 140
Replacing ....................................... 140
Replacing (rear window) ................ 141
Replacing (windshield) ................... 140
Wooden trim (cleaning instruc-
tions) .................................................. 382
Workshop
see Qualified specialist workshop
Z ZONE function
Switching on/off ........................... 157 Index 23

Protection of the environment
General notes
H Environmental note
Daimler's declared policy is one of compre-
hensive environmental protection.
The objectives are for the natural resources
that form the basis of our existence on this
planet to be used sparingly and in a manner
that takes the requirements of both nature
and humanity into account.
You too can help to protect the environment
by operating your vehicle in an environmen-
tally responsible manner.
Fuel consumption and the rate of engine,
transmission, brake and tire wear are affected
by these factors: R
operating conditions of your vehicle R
your personal driving style
You can influence both factors. You should
bear the following in mind:
Operating conditions: R
avoid short trips as these increase fuel con-
sumption. R
always make sure that the tire pressures
are correct. R
do not carry any unnecessary weight. R
remove roof racks once you no longer need
them. R
a regularly serviced vehicle will contribute
to environmental protection. You should
therefore adhere to the service intervals. R
always have service work carried out at a
qualified specialist workshop.
Personal driving style: R
do not depress the accelerator pedal when
starting the engine. R
do not warm up the engine when the vehicle
is stationary. R
drive carefully and maintain a safe distance
from the vehicle in front. R
avoid frequent, sudden acceleration and
braking. R
change gear in good time and use each gear
only up to

You could jeopardize the operating safety of
your vehicle if you use parts, tires and wheels
as well as accessories relevant to safety
which have not been approved by Mercedes.
This could lead to malfunctions in safety-rel-
evant systems, e.g. the brake system. Use
only genuine Mercedes-Benz parts or parts of
equal quality. Only use tires, wheels and
accessories that have been specifically
approved for your vehicle.
Genuine Mercedes-Benz parts are subject to
strict quality control. Every part has been spe-
cifically developed, manufactured or selected
for and adapted to Mercedes-Benz vehicles.
Only genuine Mercedes-Benz parts should
therefore be used.
More than 300,000 different genuine
Mercedes-Benz parts are available for
Mercedes-Benz models.
All authorized Mercedes-Benz Centers main-
tain a supply of genuine Mercedes-Benz parts
for necessary service and repair work. In addi-
tion, strategically located parts delivery cen-
ters provide quick and reliable parts service.
Always specify the vehicle identification num-
ber (VIN) when ordering genuine Mercedes-
Benz parts ( Y
page 446).
Operator's Manual
Vehicle equipment
This Operator's Manual describes all models
and all standard and optional equipment of
your vehicle available at the time of going to
print. Country-specific differences are possi-
ble. Bear in mind that your vehicle may not
feature all functions described here. This also
applies to safety-relevant systems and func-
tions. The equipment in your vehicle may
therefore differ from that shown in the
descriptions and illustrations.
The original purchase agreement lists all sys-
tems installed in your vehicle.
Should you have any questions concerning
equipment and operation, please consult an
authorized Mercedes-Benz Center. The Operator's Manual and Maintenance
Booklet are important documents and should
be kept in the vehicle.
Service and vehicle operation
Warranty The implied warranty for your vehicle applies
in accordance with the warranty terms and
conditions in the Service and Warranty Infor-
mation booklet.
Your authorized Mercedes-Benz Center will
replace and repair all factory-installed parts in
accordance with the following warranty terms
and conditions: R
New Vehicle Limited Warranty R
Emission System Warranty R
Emission Performance Warranty R
California, Connecticut, Maine, Massachu-
setts, New York, Pennsylvania, Rhode
Island and Vermont Emission Control Sys-
tem Warranty R
State warranty enforcement laws (lemon
laws)
Replacement parts and accessories are cov-
ered by the Mercedes-Benz Parts and Acces-
sories warranties. These are available at any
authorized Mercedes-Benz Center.
i Should you lose your Service and War-
ranty Information booklet, have an author-
ized Mercedes-Benz Center arrange for a
replacement. The new Service and War-
ranty Information booklet will be posted to
you. Introduction 25
Z

Information for customers in Califor-
niaUnder Califo rn ia law you may be entitled to a
replacement of your vehicle or a refund of the
purchase pric e or lease price, if after a rea-
son able number of repair attempts
Mercedes-Benz USA, LLC and/or it s author-
iz ed repair or service facilities fail to fix one or
more substantial defects or malfunctions in
the vehicle that are covered by it s express
warranty. During the period of 18 months
from original deliv ery of the vehicle or the
accumulation of 18,000 miles (approximately
29,000 km) on the odometer of the vehicle,
whic hever occurs first, a reasonable number
of repair attempts is presumed for a retail
buyer or lessee if one or more of the fol lowin g
occurs:
(1) the same substantial defect or malfunc-
tion results in a condition that is likely to
cause death or serious bodily injury if the
vehicle is driv en, that defect or malfunc-
tion has been subject to repair two or
more times, and you have direct ly noti-
fied Mercedes-Benz USA, LLC in writ ing
of the need for it s repair,
(2) the same substantial defect or malfunc-
tion of a less serious nature than cate-
gory (1) has been subject to repair four or
more times and you have directly notified
us i n writ ing of the need for its repair, or
(3) the vehicle is out of service by reason of
repair of the same or different substantial
defects or malfunctions for a cumulative
total of more than 30 calendar days.
Please send your written notice to:
Mercedes-Benz USA, LLC
Customer Assistance Center
One Mercedes Drive
Montvale, NJ 07645-0350 Maintenance The Se rvice and Warranty Booklet describes
all the necessary maintenance work which
should be done at regular intervals.
Always have the Se rvice and Warranty Book-
let with you when you bring the vehicle to an
authorized Mercedes-Benz Center. The ser-
vice advisor will record every ser vic e for you
in the Se rvice and Warranty Booklet.
Breakdown assistance The Mercedes-Benz Roads ide Assistance
Program offers technical help in the event of a
breakdown. Calls to the toll-free Roads ide
Assistance Hotline are answered by our
agents 24 hours a day, 365 days a year.
1-800-FOR-MERCedes(1- 800-367-6372 )
(USA)
1-8 00-387-0100 (Canada)
For additional information, refer to the
Mercedes-Benz Roads ide Assistance Pro-
gram brochure (USA) or the "Roadside Assis-
tance" section in the Se rvice and Warranty
booklet (Canada). You will find both in your
vehicle literature portfolio.
Change of address or change of own-
ership
In the event of a change of address, please
send us the "Not ific ation of Address Change"
in the Se rvice and Guarantee booklet or sim-
ply call the Mercedes-Benz Customer Assis-
tance Center (USA) at the hotline number
1-800-FOR-MERCedes(1-800-367-6372) or
Customer Service Center (Canada) at
1-800-387-0100. This will assist us in con-
tacting you in a timely manner should the
need arise.
If you sell your Mercedes, please leave the
entire literature in the vehicle so that it is
available to the next owner.
If you have purchased a used car, please send
us the "Notification of Used Car Purchase" in26
Introduction

the Service and Guarantee booklet or simply
call the Mercedes-Benz Customer Assistance
Center (USA) at the hotline number
1-800-FOR-MERCede s(1 -800-367-6372) or
Customer Service (Canada) at
1-800-387-0100.
Vehicle operation outside the USA
and Canada If you plan to operate your vehicle in foreign
countries, please be aware that: R
service facilities or replacement parts may
not be readily available. R
unleaded fuel for vehicles with a catalytic
converter may not be available. Leaded fuel
may cause damage to the catalytic con-
verter. R
the fuel may have a considerably lower
octane rating. Unsuitable fuel can cause
engine damage.
Some Mercedes-Benz models are available
for delivery in Europe through our European
Delivery Program. For details, consult an
authorized Mercedes-Benz Center or write to
one of the following addresses.
In the USA
Mercedes-Benz USA, LLC
European Delivery Department
One Mercedes Drive
Montvale, NJ 07645-0350
In Canada
Mercedes-Benz Canada, Inc.
European Delivery Department
98 Vanderhoof Avenue
Toronto, Ontario M4G 4C9
Sports Utility Vehicle
G WARNING
Due to the high center of gravity, the vehicle
may start to skid and roll over in the event of
an abrupt steering maneuver and/or when the vehicle's speed is not adapted to the road
conditions. There is a risk of an accident.
Always adapt your speed and driving style to
the vehicle's driving characteristics and to the
prevailing road and weather conditions.
Utility vehicles have a significantly higher roll-
over rate than other types of vehicles.
Failure to operate this vehicle safely may
result in an accident, rollover of the vehicle,
and severe or fatal injury.
In a rollover crash, an unbelted person is sig-
nificantly more likely to die than a person
wearing a seat belt.
You and all vehicle occupants should always
wear your seat belts.
Operating safety
Important safety notes
G WARNING
If you do not have the prescribed service/
maintenance work or any required repairs
carried out, this can result in malfunctions or
system failures. There is a risk of an accident.
Always have the prescribed service/mainte-
nance work as well as any required repairs
carried out at a qualified specialist workshop.
G WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system. There is a risk
of fire.
When driving off road or on unpaved roads,
check the vehicle's underside regularly. In
particular, remove parts of plants or other
flammable materials which have become
trapped. In the case of damage, contact a
qualified specialist workshop.
G WARNING
Modifications to electronic components, their
software as well as wiring can impair their
function and/or the function of other net- Introduction 27
Z

worked components. In particular, systems
relevant to safety could also be affected. As a
result, these may no longer function as inten-
ded and/or jeopardize the operating safety of
the vehicle. There is an increased risk of an
accident and injury.
Never tamper with the wiring as well as elec-
tronic components or their software. You
should have all work to electrical and elec-
tronic equipment carried out at a qualified
specialist workshop.
! There is a risk of damage to the vehicle if: R
the vehicle becomes stuck, e.g. on a high
curb or an unpaved road R
you drive too fast over an obstacle, e.g. a
curb or a hole in the road R
a heavy object strikes the undercarriage
or parts of the chassis
In situations like this, the body, the under-
carriage, chassis parts, wheels or tires
could be damaged without the damage
being visible. Components damaged in this
way can unexpectedly fail or, in the case of
an accident, no longer withstand the strain
they are designed to.
If the underbody paneling is damaged,
combustible materials such as leaves,
grass or twigs can gather between the
underbody and the underbody paneling. If
these materials come in contact with hot
parts of the exhaust system, they can catch
fire.
In such situations, have the vehicle
checked and repaired immediately at a
qualified specialist workshop. If on con-
tinuing your journey you notice that driving
safety is impaired, pull over and stop the
vehicle immediate ly,
paying attention to
road and traffic conditions. In such cases,
consult a qualified specialist workshop. Declarations of conformity
Vehicle components which receive
and/or transmit radio waves USA: "The wireless devices of this vehicle
comply with Part 15 of the FCC Rules. Oper-
ation is subject to the following two condi-
tions: 1) These devices may not cause harm-
ful interference, and 2) These devices must
accept any interference received, including
interference that may cause undesired oper-
ation. Changes or modifications not expressly
approved by the party responsible for com-
pliance could void the user’s authority to
operate the equipment."
Canada: "The wireless devices of this vehicle
comply with Industry Canada license-exempt
RSS standard(s). Operation is subject to the
following two conditions: (1) These devices
may not cause interference, and (2) These
devices must accept any interference, includ-
ing interference that may cause undesired
operation of the device."
Diagnostics connection
The diagnostics connection is only intended
for the connection of diagnostic equipment at
a qualified specialist workshop.
G WARNING
If you connect equipment to the diagnostics
connection in the vehicle, it may affect the
operation of the vehicle systems. As a result,
the operating safety of the vehicle could be
affected. There is a risk of an accident.
Do not connect any equipment to a diagnos-
tics connection in the vehicle.
G WARNING
Objects in the driver's footwell can restrict the
pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter28
Introduction