fuel additives TOYOTA 4RUNNER 1999 Owners Manual

4RUNNER ()173
OCTANE RATING
Select Octane Rating 87 (Research Oc-
tane Number 91) or higher.
Use of unleaded gasoline with an octane
rating or research octane number lower
than stated above will cause persistent
heavy knocking. If it is severe, this will
lead to engine damage.
If your engine knocks...
If you detect heavy knocking even when
using the recommended fuel, or if you
hear steady knocking while holding a
steady speed on level roads, consult your
Toyota dealer.
However, now and then, you may notice
light knocking for a short time while accel-
erating or driving up hills. This is no need
of concern.
GASOLINES CONTAINING DETERGENT
ADDITIVES
Toyota recommends use of gasolines
that contain detergent additives to
avoid build- up of engine deposits.
For further details, ask your Toyota dealer
or a local gasoline retailer.
IMPROVED GASOLINES
The American Automobile Manufacturers
Association (AAMA) has developed a
specification of improved gasolines. The
AAMA specification offers optimal fuel
information for better vehicle perfor-
mance and better protection of your en-
gine.
Toyota recommends the use of gasolines
that meet the AAMA specification, if avail-
able, for improved driveability and emis-
sion control system.
GASOLINES CONTAINING MTBE
Gasolines that contain MTBE (Methyl
Tertiary- Butyl Ether) are available in the
market. If you use a gasoline mixed
with MTBE, make certain that it does
not contain more than 15% of MTBE.
GASOLINES CONTAINING MMT
Some gasolines contain an
octane- enhancing additive called MMT
(methylcyclopentadienyl manganese
tricarbonyl).
Toyota does not recommend the use of
gasolines that contain MMT. If fuels con-
taining MMT are used, your emission con-
trol system may be adversely affected.
The Malfunction Indicator Lamp on the in-
strument cluster may come on. If this hap-
pens, contact your Toyota dealer for ser-
vice.
GASOLINES CONTAINING ALCOHOL
If you use gasohol in your Toyota, be
sure that it is unleaded, has an octane
rating no lower than 87 and does not
contain more than 10% ethanol.
Gasohol is a mixture of gasoline and etha-
nol.
Toyota does not recommend the use of
gasolines containing methanol. If you use
gasoline containing methanol, use only
gasoline meeting the requirements above
and also containing less than 5% metha-
nol with cosolvents and corrosion inhibi-
tors for methanol.
GASOLINES QUALITY
In a very few cases, you may experience
driveability problems caused by the partic-
ular gasoline that you are using. If you
continue to have unacceptable driveability,
try changing gasoline brands. If that does
not rectify your problem, then consult your
Toyota dealer.