By Dicor Corporation
As you get caught up in the summer fun of RVing, it’s easy to forget about some of the basic checks needed for maintaining the safety and performance of your RV. In this first of three reports, we’ll take a look at, first, why regularly checking your tire inflation is nothing to be lax about, and, second, the procedures and best practices for maintaining proper inflation, including keeping your RV from getting overloaded.
Underinflation: Radial tires don’t look low!
Some RVers seldom check their tires. Unless the tire actually looks like it’s low they may not want to bother with it, especially if that means also fumbling with the inner tire pressure check on a dual wheel axle. But modern radial tiresdo not look low when they are underinflated. You can really only tell by checking the pressure.
Some drivers may actually feel OK with a bit of underinflation, feeling like it provides a softer ride. This it may do, but at a price. Here are the main negative consequences of underinflation:
• Underinflated tires will tend to ride on their edges rather than their center, which will actually flexin a bit and lose solid contact with the road. This can yield less traction and, for example, make hydroplaning more likely as water is better able to get in between the tire and the pavement and cause a temporary loss of control.
• Underinflation also causes excessive tread wear on the inner and outer edges, reducing the tire’s tread life.
• Underinflation creates more “rolling resistance,” making the engine work harder to keep moving and reducing gas mileage.
• Rolling resistance with all the weight distributed to the edges also results in poorer handling, which can not only make driving more of a chore but also makes it harder to avoid potentially dangerous traffic situations.
• Longer braking time is also required with underinflated tires because the center is not gripping the road well.
• And, finally, underinflated tires can generate excessive heat and cause excessive flexing of the sidewalls, both of which can make the tire more vulnerable to quick spikes in pressure when hitting a bump or pothole, or simply deteriorate the strength of the tire over time. Either of these situations can result in a dangerous blowout or a less dramatic failure early in the tire’s lifecycle.
Overinflation: Opposite but the same!
You can look at overinflation as the opposite problem but with similar results. Again, the main result is an uneven distribution of weight across the entire tread base of the tire.
• In overinflated tires, it is the center that bulges out more with the tire edges losing their grip on the road. The RV then rides on a smaller footprint, resulting in less control and traction, making slipping and sliding on water and in other conditions easier.
• Braking is also not as good because of this loss of “road grip.”
• Wear on the center treads is excessive, again more quickly reducing the tire’s life cycle.
• Overinflated tires can’t absorb the bumps in the road as well as properly inflated tires, and results in a bumpier ride. The harder sidewall also transfers more noise to the interior of the RV.
• The overly pressurized tire becomes more vulnerable to a blowout from a bumpy pressure spike or from excessive heat buildup that places extra stress on the sidewalls.
In addition, both underinflated and overinflated tires make failure from an overloaded RV more likely. It’s a given that most tires will lose a certain amount of pressure over time, so underinflation becomes the default mode unless you stay on top of it. Overall, along with safety issues, over- and underinflated tires can put an unnecessary hurt on your pocketbook with on-the-road breakdowns, poorer gas mileage and sooner-than-necessary tire replacements.
The key to avoiding such problems is maintaining optimal inflation to keep the most rubber firmly on the road by knowing and adhering to the proper pressure and through regular and frequent pressure checks, which we will discuss in our next report.
EDITOR’S NOTE: Our RV tire expert Roger Marble disagreed with the following statement after reading this article:
“The overly pressurized tire becomes more vulnerable to a blowout from a bumpy pressure spike or from excessive heat buildup that places extra stress on the sidewalls.”
Roger noted: Actually, the “blowout” from pressure spike perpetuates the misinformation on the cause of a blowout. Tires can handle many times their inflation pressure so the theoretical couple of psi “spike” isn’t going to cause a tire to explode. Heat buildup comes from bending of the rubber not from higher stress. Sidewalls are one of the cooler sections of a tire so even if their theory was correct it isn’t supported by the facts of what part of the tire is warmest or how the stress of increased inflation is handled by a tire.