Pontiac 2005 Bonneville Owner's Manual page 342

High Speed Operation
CAUTION:
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Driving at high speeds, 100 mph (160 km/h) or
higher, puts an additional strain on tires.
Sustained high-speed driving, causes
excessive heat build up and can cause sudden
tire failure. You could have a crash and you or
others could be killed. Some high-speed rated
tires require inflation pressure adjustment for
high speed operation. When speed limits and
road conditions are such, that a vehicle can be
driven at high speeds, make sure the tires are
rated for high speed operation, in excellent
condition and set to the correct cold tire
inflation pressure for the vehicle load.
5-82
If you'll be driving at high speeds, speeds of 100 mph
(160 km/h) or higher, where it is legal, set the cold
inflation pressure to the maximum inflation pressure
shown on the tire sidewall, or to 35 psi (244 kPa),
whichever is lower. See the example below. When you
end this high-speed driving, return to the cold inflation
pressure shown on the Tire and Loading Information
label. See Loading Your Vehicle on page 4-29.
Example:
You'll find maximum load and inflation pressure molded
on the tire's sidewall, in small letters near the rim
flange. It will read something like this: Maximum load
690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the inflation pressure
for high-speed driving at 35 psi (244 kPa).