By Mark Polk
RV Education 101
We often talk about the importance of checking the inflation pressure in your motorhome’s tires, but is your tire pressure gauge giving you accurate information
As a Maintenance Warrant Officer in the U.S. Army, I was responsible for tool calibration programs. Certain tools required regular calibration to ensure accuracy.
As a motorhome owner, I’ve always used a quality tire pressure gauge. But after several years of using this gauge, I realized it had never had it checked for accuracy.
Many of the inexpensive gauges ($5) that you can purchase can’t be calibrated, and if the reading is inaccurate the gauge is worthless. That’s why you should spend a little more ($15 to $25) and get a quality pressure gauge that can be calibrated. I am a real believer in the old saying: You get what you pay for.
Here are some simple things you can do to really know how much air pressure is in your tires.
1. Check the air pressure in a tire with the gauge in question and then check the same tire with another gauge. If there is a significant difference in the readings (4 or more psi) between the two gauges, one or both gauges may be inaccurate. If both gauges read within 1 to 2 psi of each other, the gauges are more than likely accurate.'2. If you want a more precise method for checking the accuracy, take the gauge to a local tire dealer or fleet truck maintenance facility and ask them to check it using a master gauge. A master gauge is a gauge that is certified to be accurate. But I caution you: There are many tire dealers who don’t have their own tire pressure gauges calibrated.
3. Don’t depend on pressure gauges at gas stations to be accurate. These are usually abused and neglected, raising concern over accuracy.
4. There are several different types of pressure gauges available on the market. One important thing to keep in mind is the pressure the gauge is rated for. Most automobile tires are inflated to around 32 psi, so a 0 to 60 psi gauge is sufficient. On the other hand, some motorhome and truck tires are inflated to 100 psi, or more.
It is important, for accuracy, and to prevent damage to the gauge, that you get the right gauge for the job. A general rule of thumb is to find a gauge that can read double what the inflation pressure is set at. This isn’t always possible, especially with tires inflated to 100 psi, so find a gauge rated for high pressure, like 160 psi.
5. Possibly the most common type of pressure gauge is the plunge or pencil type. Some of these are calibrated and some of the cheaper ones are not. As a general rule, a common plunge type gauge will be accurate to + or – 3 psi when it is new. The accuracy of these type of gauges are also affected by temperature, humidity and altitude.
6. Like everything else these days, things are switching from analog to digital. Analog tire pressure gauges were the standard for many years, but advancements in digital technology have improved on that standard. Analog dial gauges are about as accurate as the quality pencil type gauges. In numerous tests comparing different types of gauges, digital gauges were the most accurate. So get with the times and go digital.
7. Regardless of the type of gauge you choose, there are high-quality and low-quality gauges available. Buying a cheap digital gauge would be the same as buying a cheap pencil type gauge. Here are a few things to keep in mind when it comes to tire pressure gauges.
- Spend a few more dollars and get a quality pressure gauge.
- If the gauge will be used for checking dual wheels on a motorhome, the chuck end of the gauge should have a dual foot design to make the job much easier.
- Always select a gauge rated higher than the inflation pressure of the tires you are checking. Applying more pressure than the gauge is rated for can damage the gauge and affect the accuracy. If you over-pressure a gauge, have it tested for accuracy.
- Try not to drop or jar the gauge. Store the gauge in some type of protective covering or case and in an area where it won’t be hit or damaged.
- Periodically have the gauge tested for accuracy. At a minimum, compare it to another quality gauge to see if both read the same, or close to the same, pressure.
- Most important, once you purchase a quality pressure gauge, use it on a regular basis to check your tires.
Properly inflated tires are safer, extend the life of the tires, improve fuel efficiency and lessen the chance of unexpected and premature tire failure.
|RV expert Mark Polk owns RV Education 101, a North Carolina-based company that produces and sells educational videos, DVDs and E-books on how to use RVs. Mark has more than 30 years of experience in RV maintenance. He retired from the U.S. Army in 1996 as a Chief Warrant Officer Three, specializing in wheeled and track vehicle fleet maintenance operations. He and his wife, Dawn, started RV Education 101 in 1999. They travel with their two boys in a 35-foot Type A motorhome.