2004 Mercury Mountaineer Owner's Manual - Page 254

Maintenance and Specifications Use a tire gauge to check the tire inflation pressure, including the spare, at least monthly and before long trips. You are strongly urged to buy a reliable tire pressure gauge, as automatic service station gauges may be inaccurate. Ford recommends the use of a digital or dial type tire pressure gauge rather than a stick type tire pressure gauge. Use the recommended cold inflation pressure for optimum tire performance and wear. Under-inflation or over-inflation may cause uneven treadwear patterns. Under-inflation is the most common cause of tire failures and may result in severe tire cracking, tread separation or blowout , with unexpected loss of vehicle control and increased risk of injury. Under-inflation increases sidewall flexing and rolling resistance, resulting in heat buildup and internal damage to the tire. It also may result in unnecessary tire stress, irregular wear, loss of vehicle control and accidents. A tire can lose up to half of its air pressure and not appear to be flat! When weather temperature changes occur, tire inflation pressures also change. A 10° F (6° C) temperature change can cause a corresponding drop of 1 psi (7 kPa) in inflation pressure. Check your tire pressures frequently and adjust them to the proper pressure which can be found on the tire label or certification label. If you are checking tire pressure when the tire is hot, (i.e. driven more than 1 mile [1.6 km]), never "bleed" or reduce air pressure. The tires are hot from driving and it is normal for pressures to increase above recommended cold pressures. A hot tire at or below recommended cold inflation pressure could be significantly under-inflated. To check the pressure in your tire(s): 1. Make sure the tires are cool, meaning they are not hot from driving even a mile. Note: If you have to drive a distance to get air for your tire(s), check and record the tire pressure first and add the appropriate air pressure when you get to the pump. It is normal for tires to heat up and the air pressure inside to go up as you drive. Never "bleed" or reduce air pressure when tires are hot. 2. Remove the cap from the valve on one tire, then firmly press the tire gauge onto the valve and measure the pressure. 3. Add enough air to reach the recommended air pressure Note: If you overfill the tire, release air by pushing on the metal stem in the center of the valve. Then recheck the pressure with your tire gauge. 254 REVIEW COPY: 2004 Explorer (exp), Owners Guide (post-2002-fmt) (own2002), Market: USA English (fus)