FORD 1998 Ranger - Manual (Page 136)

• Be particularly careful if you are taking “Antabuse” or other forms of
disulfiram for the treatment of alcoholism. Breathing gasoline vapors
or skin contact could cause an adverse reaction. Consult a physician
immediately.
Choosing the right fuel
Use only UNLEADED FUEL. The use of leaded fuel is prohibited by law
and could damage your vehicle.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based compounds containing MMT.
Vehicles certified to California emission standards (indicated on the
underhood Vehicle Emissions Control Information label) are designed to
operate on California reformulated gasolines. If California reformulated
gasoline is not available when you refuel, your vehicle can be operated
on non-California fuels. However, even though your engine will perform
adequately on other gasolines, the performance of the emission control
devices and systems may be adversely affected.
Repair of damage caused by using a fuel for which your vehicle was not
designed may not be covered by your warranty.
Octane recommendations
Your vehicle is designed to use
“Regular” unleaded with an (R+M)/2
octane rating of 87. We do not
recommend gasolines labeled as
“Regular” that are sold with octane
ratings of 86 or lower in high
altitude areas.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily under most driving conditions while you are using fuel
with the recommended octane rating, see your dealer or a qualified
service technician to prevent any engine damage.
Fuel quality
If you are experiencing starting, rough idle or hesitation driveability
problems during a cold start, try a different brand of “Regular” gasoline.
“Premium” gasoline is not recommended (particularly in the United
States) because it may cause these problems to become more
pronounced. If the problems persist, see your dealer or a qualified
service technician.
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Maintenance and care
136