FORD 2000 Focus - Manual (Page 220)

Maintenance and care
220
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 fuel. 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