Cronk Ministries

Archive for September, 2009

The number one reason for premature tire failure is improper inflation pressure. For best results, keep the tires at the inflation pressure reconunended by the vehicle maker. (You’ll find this information in the owner’s manual.) The pressure branded on the sidewall is the maximum and should be followed only when the vehicle is carrying an extremely heavy load.
There are exceptions to this rule. A common offroad tactic is to reduce tire pressure to improve driving performance. This is ordinarily done when driving over sand, where airing down widens and lengthens the tire’s “footprint.” Doing so puts more tire in contact with the sand, improving traction. Airing down also works on rocky or stump-studded trails. In this case, the lower inflation pressure allows the tire to wrap itself around a rock, which reduces the chance of a sidewall puncture.
When driving through this type of terrain, impact absorption takes precedence over quick-steering response. For this reason, tire pressures as low as 25 pounds per square inch (psi) may be used, so long as speeds are less than 15 mph.
Be sure the tire has adequate load-carrying capacity at these lower pressures. To be safe, don’t go below 18 psi. The disadvantage to airing down is that you increase the probability of pushing a tire off the rim. Be alert.
Always make sure the tires are returned to the proper inflation pressures before you return to the highway. Severe internal tire damage or outright failure can occur when an underinflated tire is driven at typical highway speeds.