Fuel
Types
And
Vapor Lock
Today's automotive fuel
and
emissions systems
are
sophisticated
and
highly engineered
to
meet
Federal
and
state emissions standards. They
are
also sometimes
sen-
sitive to fuel types
and
blends, particularly blends that
are
optimized for climatic conditions.
Fuel
refiners change
the additives
in
the fuel
to
compensate for temperature
variations during winter or summer months. This com-
pensation changes the "vapor pressure" of the fuel. This
means
that
the fuel vaporizes easier during the winter
than it does during the summer when higher air
temperatures help the fuel vaporize
in
the engine. Since
colder temperatures reduce the fuel's ability
to
vaporize
and
burn
in
your engine, additives help
raise
the volatili-
ty
of the fuel. This helps the engine start easier and
run smoother during winter months. Under the best of
conditions, the refiners supply their
gas
station customers
with the correct fuel for their location
and
seasonal con-
ditions. Sometimes though, fuel blended for winter
is
supplied during summer months.
What this
all
means
is
that there
is
a possibility of
"vapor
lock"
during summer driving. This condition
is
a combination of new engine design (with attendant
higher temperatures under the hood),
and
excessive fuel
vaporization caused by the vapor pressure of the fuel
you
are
using. If your engine
and
fuel system
are
pro-
perly tuned and maintained, you should not experience
vapor lock. If vapor lock occurs, the fuel itself could
be
the
cause.
If at
all
possible, check
with
the gas sta-
tion attendant
as
to the fuel blend before filling your
fuel tank. If you purchase your fuel from nationally
recognized fuel dealers, your chances of vapor lock can
be
reduced. If you store your motor home during the
winter months, avoid storing large quantities of winter
blended fuel in the tank. When you take the vehicle out
of storage
in
the spring or summer,
this
fuel may cause
vapor lock until it
is
used
up.
Another note on long storage -if you plan to store
your motor home for a long
period
in
conditions of widely
varying humidity, consider topping
off
the fuel tank. This
will reduce the buildup of condensation
in
the tank that
could cause rough engine operation, fuel filter blockage,
or other problems associated
with
water in the fuel.
Alternative Fuel
Types
Gasohol, a mixture of ethanol (grain alcohol), or
methanol
and
gasoline may
be
used
in
your motor home
engine without voiding the warranty. However,
DD
NOT
UNDER
ANY CiRCUMSTANCES
USE
FUEL
BLENDS
CONTAINING
MORE
THAN 5% METHANOL
OR
10%
ETHANOL,
AND
DO
NOT
USE
BLENDS
THAT
CONTAIN
BOTH
METHANOL AND ETHANOL. Any fuel blend you
use
containing alcohol must also contain cosolvents
and
other additives
to
protect the fuel system components.
If you
are
not sure
of
the composition of the
alcohol/gasoline blend you intend to
use,
ask your ser-
vice
station
operator. Discontinue use of any
alcohol/gasoline blend if driveability or fuel system pro-
blems occur.
Chemical reactions between the fuel components
and
10
the materials
in
the fuel lines can cause deterioration
of the fuel lines during storage periods. These effects
are
especially noticeable with gasohol
blends.
If you
plan
to use alcohol blended fuel,
and
expect
to
store your
motor home for periods of
60
days or
more,
add
a fuel
additive
that
is
formulated to counteract these oxida-
tion effects.
Your
dealer can advise you on the proper
additives and their
use.
If gasohol
is
spilled on a painted surface, some dull-
ing or softening of the paint may result.
Overheating
Operate and service the engine
and
Gooling systems
in your vehicle
as
recommended in the Chassis
Operator's Manual.
Variable Speed Engine
Fan
Your
motor home engine
is
equipped
with
a variable
speed fan clutch. When the engine
is
under load or
re-
quires maximum cooling, the
fan
adjusts
and
turns
faster.
The fan may become very noisy at high
speed
and
when
maximum cooling
is
required. When the engine doesn't
need maximum cooling, the fan just idles along. This
conserves fuel
and
the fan
is
less
noisy.
High
speed
fan noise
can
sometimes
be
misinterpreted
as
transmission slippage. This
is
not the
case.
When
the engine
is
hot
and
requires
extra cooling, the fan turns
at full speed. High engine speed
and
temperature con-
ditions, such
as
pulling away from a stop after long
freeway driving,
can
cause
loud
fan
noise until the engine
cools down. This fan noise indicates
that
the fan
is
do-
ing
what
it
is
supposed to
do.
This noise
is
not a defect
in the fan or the transmission.
ENGINE EXHAUST SYSTEM COMPONENTHEAT
Your
motor home engine has been designed
to
con-
form
with
Federal
and
State emission requirements.
To
meet these requirements, engine operating temperatures
are
high. As a result, the engine
and
exhaust system
components radiate a great deal of heat.
Parts
of the
exhaust system may operate at temperatures near
700
degrees
F.
The temperatures
are
normal for your vehicle.
Special heat shields may
be
built into your vehicle
to protect wiring or other components from possible
heat damage caused by the exhaust system. Do not
modify or remove these shields without consulting your
RV
dealer. If you want
to
install equipment, add wiring,
plumbing, or other components
near
the exhaust system
or the heat shields, do
so
only after you thoroughly in-
vestigate
and
understand
how
the equipment will
be
affected by the heat radiated by the exhaust system.
CARBON
MONOXIDE
SAFETY PRECAUTIONS
Carbon monoxide
is
a colorless, tasteless, odorless
gas.
It
is
a by-product of combustion in engine(s). The
engines
in
your motor home
and
generator system (if
installed) produce
it
constantly while they
are
running.
CARBON
MONOXIDE
IS
DEADLY.
Please
read
and
understand the following precautions to protect yourself
and
others from the effects of carbon monoxide
poisoning.