FORD 2002 Focus v.2 - Manual (Page 291)

Maintenance and Specifications
291
Octane recommendations
Your vehicle is designed to use
regular" unleaded gasoline 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"
unleaded gasoline. Premium"
unleaded 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 qualified
service technician.
87
(R+M)/2 METHOD