Here is some info from the 2014 FIESTA ST Supplement:
Operating at High Speeds
Your ST vehicle is capable of high speeds
and is equipped with tires rated for the
vehicle’s maximum speed. Remember to
drive safely, obey all traffic laws and only
operate your ST vehicle at high speeds at
locations equipped and designed to do so
safely. Before operating your vehicle at
high speeds:
• Verify correct tire pressures. See Tires
(page 20).
• Inspect wheels and tires for wear and
damage. Replace any damaged wheels
or tires.
• Do not operate your vehicle at high
speeds with more than two passengers
or while carrying cargo.
Tire Pressure for High Speed Usage
If you are operating your ST vehicle in areas
that allow high-speed driving over 100 mph
(161 km/h), increase the tire pressure in all
four tires by 3 psi above the pressures
listed on the Tire Pressure placard located
on the driver’s side b-pillar.
