Jeep Grand Cherokee 2020 Owner's Manual page 355

Fuel Economy
Underinflated tires will increase tire rolling
resistance resulting in higher fuel consumption.
Tread Wear
Improper cold tire inflation pressures can cause
abnormal wear patterns and reduced tread life,
resulting in the need for earlier tire
replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a
comfortable ride. Overinflation produces a
jarring and uncomfortable ride.
Tire Inflation Pressures
The proper cold tire inflation pressure is listed
on the driver's side B-Pillar or rear edge of the
driver's side door.
At least once a month:
Check and adjust tire pressure with a good

quality pocket-type pressure gauge. Do not
make a visual judgement when determining
proper inflation. Tires may look properly
inflated even when they are under-inflated.
Inspect tires for signs of tire wear or visible

damage.
CAUTION!
After inspecting or adjusting the tire pressure,
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the
valve stem, which could damage the valve
stem.
Inflation pressures specified on the placard are
always "cold tire inflation pressure". Cold tire
inflation pressure is defined as the tire pressure
after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km)
after sitting for a minimum of three hours. The
cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall.
Check tire pressures more often if subject to a
wide range of outdoor temperatures, as tire
pressures vary with temperature changes.
Tire pressures change by approximately 1 psi
(7 kPa) per 12°F (7°C) of air temperature
change. Keep this in mind when checking tire
pressure inside a garage, especially in the
Winter.
SERVICING AND MAINTENANCE
Example: If garage temperature = 68°F (20°C)
and the outside temperature = 32°F (0°C) then
the cold tire inflation pressure should be
increased by 3 psi (21 kPa), which equals 1 psi
(7 kPa) for every 12°F (7°C) for this outside
temperature condition.
Tire pressure may increase from 2 to 6 psi
(13 to 40 kPa) during operation. DO NOT reduce
this normal pressure build up or your tire
pressure will be too low.
Tire Pressures For High Speed Operation
The manufacturer advocates driving at safe
speeds and within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds,
maintaining correct tire inflation pressure is
very important. Increased tire pressure and
reduced vehicle loading may be required for
high-speed vehicle operation. Refer to an
authorized tire dealer or original equipment
vehicle dealer for recommended safe operating
speeds, loading and cold tire inflation
pressures.
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