2010 GMC YUKON fuel cap

Towing a Trailer
If the vehicle has a two–mode hybrid engine, see the
Two–mode Hybrid manual for more information.
Do not tow a trailer during break‐in. SeeNew Vehicle
Break-In
on page 3‑27for more information.
{WARNING:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is
too heavy, the brakes may not work well —or
even at all. The driver and passengers could
be seriously injured. The vehicle may also be
damaged; the resulting repairs would not be
covered by the vehicle warranty. Pull a trailer only
if all the steps in this section have been followed.
Ask your dealer for advice and information about
towing a trailer with the vehicle. Notice:
Pulling a trailer improperly can damage
the vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your dealer
for important information about towing a trailer with
the vehicle.
To identify the trailering capacity of the vehicle, read the
information in “Weight of the Trailer” that appears later
in this section.
Trailering is different than just driving the vehicle
by itself. Trailering means changes in handling,
acceleration, braking, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
The following information has many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully
before pulling a trailer.
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Vehicles that have a FlexFuel badge and a yellow fuel
cap can use either unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85). SeeFuel E85
(85% Ethanol)
on page 6‑9. For all other vehicles,
use only the unleaded gasoline described under
Gasoline Octane on page 6‑7.
Gasoline Octane
For all vehicles except those with the 6.2L V8 engine
(VIN Code 2), use regular unleaded gasoline with a
posted octane rating of 87 or higher. If the octane
rating is less than 87, an audible knocking noise,
commonly referred to as spark knock, might be heard
when driving. If this occurs, use a gasoline rated at
87 octane or higher as soon as possible. If heavy
knocking is heard when using gasoline rated at
87 octane or higher, the engine needs service. If the vehicle has the 6.2L V8 engine (VIN Code 2), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle's
acceleration could be slightly reduced, and a slight
audible knocking noise, commonly referred to as spark
knock, might be heard. If the octane is less than 87, you
might notice a heavy knocking noise when you drive.
If this occurs, use a gasoline rated at 87 octane or
higher as soon as possible. Otherwise, you could
damage the engine. If heavy knocking is heard when
using gasoline rated at 87 octane or higher, the engine
needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB‐3.5 or 3.511 in Canada. Some gasolines
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
We recommend against the use of gasolines containing
MMT. See
Additives
on page 6‑8for additional
information.
6-7

Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer for service.
Fuel E85 (85% Ethanol)
Vehicles that have a FlexFuel badge and a yellow fuel
cap can use either unleaded gasoline or ethanol fuel
containing up to 85% eithanol (E85). For all other
vehicles, use only the unleaded gasoline described
underGasoline Octane
on page 6‑7.
We encourage the use of E85 in vehicles that are
designed to use it. The ethanol in E85 is a "renewable"
fuel, meaning it is made from renewable sources such
as corn and other crops. Many service stations will not have an 85% ethanol
fuel (E85) pump available. The U.S. Department
of Energy has an alternative fuels website
(www.afdc.energy.gov/afdc/locator/stations/) that
can help you find E85 fuel. Those stations that do have
E85 should have a label indicating ethanol content.
Do not use the fuel if the ethanol content is greater
than 85%.
At a minimum, E85 should meet ASTM Specification
D 5798. By definition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%.
Filling the fuel tank with fuel mixtures that do not meet
ASTM specifications can affect driveability and could
cause the malfunction indicator lamp to come on.
6-9

Filling the Tank
{WARNING:
Fuel vapor burns violently and a fuel fire can
cause bad injuries. To help avoid injuries to you
and others, read and follow all the instructions on
the fuel pump island. Turn off the engine when
refueling. Do not smoke near fuel or when
refueling the vehicle. Do not use cellular phones.
Keep sparks, flames, and smoking materials away
from fuel. Do not leave the fuel pump unattended
when refueling the vehicle. This is against the law
in some places. Do not re-enter the vehicle while
pumping fuel. Keep children away from the fuel
pump; never let children pump fuel.
The tethered fuel cap is located behind a hinged fuel
door on the driver side of the vehicle. If the vehicle has
E85 fuel capability, the fuel cap will be yellow and state
that E85 or gasoline can be used. SeeFuel E85
(85% Ethanol) on page 6‑9.
6-11

To open the fuel door, push the rearward center edge in
and release and it will open.
To remove the fuel cap, turn it slowly counterclockwise.
The fuel cap has a spring in it; if the cap is released too
soon, it will spring back to the right.
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
{WARNING:
Fuel can spray out on you if you open the fuel cap
too quickly. If you spill fuel and then something
ignites it, you could be badly burned. This spray
can happen if the tank is nearly full, and is more
likely in hot weather. Open the fuel cap slowly and
wait for any hiss noise to stop. Then unscrew the
cap all the way.
Be careful not to spill fuel. Do not top off or overfill the
tank and wait a few seconds after you have finished
pumping before removing the nozzle. Clean fuel from
painted surfaces as soon as possible. See Washing
Your Vehicle on page 6‑112.
6-12

When replacing the fuel cap, insert the tether in its hole
before tightening the cap. Turn the fuel cap clockwise
until it clicks. It will require more effort to turn the fuel
cap on the last turn as you tighten it. Make sure the cap
is fully installed. The diagnostic system can determine
if the fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the atmosphere.
SeeMalfunction Indicator Lamp on page 4‑39.
If the vehicle has a Driver Information Center (DIC), the
TIGHTEN GAS CAP message displays if the fuel cap is
not properly installed.
{WARNING:
If a fire starts while you are refueling, do not
remove the nozzle. Shut off the flow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice: If you need a new fuel cap, be sure to get
the right type. Your dealer can get one for you.
If you get the wrong type, it may not fit properly.
This may cause the malfunction indicator lamp to
light and may damage the fuel tank and emissions
system. See Malfunction Indicator Lamp
on
page 4‑39.
Filling a Portable Fuel Container
{WARNING:
Never fill a portable fuel container while it is in
the vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
.Dispense fuel only into approved containers.
.Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed,
or on any surface other than the ground.
.Bring the fill nozzle in contact with the inside
of the fill opening before operating the nozzle.
Contact should be maintained until the filling is
complete.
.Do not smoke while pumping fuel.
.Do not use a cellular phone while
pumping fuel.
6-13

Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview
on page 6‑16for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If this is not done, the
oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is below the cross-hatched area at the
tip of the dipstick, add at least one quart/liter of the
recommended oil. This section explains what kind of
oil to use. For engine oil crankcase capacity, see
Capacities and Specifications on page 6‑126.
Notice: Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
6-18

Tire Terminology and Definitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the tire.
Air pressure is expressed in pounds per square
inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire's height to
its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread. Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat
from driving. See Inflation - Tire Pressure
on
page 6‑72
.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant, but
without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identification Number (TIN), an
alphanumeric designator which can also identify
the tire manufacturer, production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight Rating.
See Loading the Vehicle
on page 5‑31.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. See Loading the Vehicle
on page 5‑31.
GAWR RR
:Gross Axle Weight Rating for the rear
axle. See Loading the Vehicle
on page 5‑31.
6-69