Tire pressure?
Pro
Joined: Nov 2000
Posts: 501
Likes: 1
Try Nitrogen for more stable tire pressures!
I have specified nitrogen at my local Discount Tire store when buying new tires in the past few years, nitrogen is far more stable than compressed air with better pressure readings for longer periods.
Here is some good info from Ingersoll-Rand on using Nitrogen:
Nitrogen Tire Filling. A competitive advantage.
Now, Ingersoll Rand offers you a choice. You can use nitrogen, not ambient air, to fill tires with the new Nitrogen Tire Inflation System. A revolutionary technology in tire inflation. You gain a competitive edge by enhanced tire pressure retention. Bringing tire inflation and, in turn, travel to a new level. Creating a new source of revenue for your business. Improving tire performance, road safety and cost savings for your customers.
Better air pressure retention. The single biggest reason for tire failure is lack of maintenance of tire pressure. In fact, 54 percent of all vehicles on the road have low tire pressure. Oxygen in compressed air can permeate the tire wall reducing tire pressure. With nitrogen, diffusion is 30 to 40 percent slower than oxygen. As a result, nitrogen maintains tire pressure longer than ambient air.
Enhanced fuel economy. Maintaining tire pressure can boost fuel economy by as much as 6 percent. Nitrogen disperses heat more quickly than ambient air. By restraining the heat in the tire and reducing rolling resistance, you get better fuel economy.
Longer tread life. With quicker heat dispersion, you get a cooler running tire which helps extend tread life and reduce tire failure. Nitrogen also prevents oxidation which can not only lead to tread separation and belt failure but, when combined with moisture, corrode rims. In fact, moisture can result in rust flakes that can fall into the valve stem, block the valve and cause under-pressurization. It can even cause the valve stem itself to rust.
Slow chemical aging. Filling a tire with nitrogen also significantly slows the chemical aging process of the tire’s rubber components. This leads to fewer catastrophic failures like blowouts. Slower aging lengthens tire core life, which yields extra retreads and lower fleet costs.
Here is a good page from the Discount Tire web site for tire pressure:
The Benefits of Correct Air Pressure
Keeping the correct air pressure in your tires is as important as giving your engine a tune up. The economic benefits are perhaps even greater! With the right amount of air pressure, your tires wear longer, save fuel, enhance handling and prevent accidents. If you consider the liabilities of not maintaining the correct air pressure -- poor gas mileage, loss of tire life, bad handling (perhaps even loss of control), and potential vehicle overloading -- then the need to routinely add air to your tires will become clearer.
Check Air Pressure Routinely
Perhaps because our tires do so much without seeming to need any attention, we tend to overlook this important task. But tires do lose pressure, slowly but surely everyday, through the process of permeation. Generally, a tire will lose one or two pounds of air per month in cool weather and even more in warmer weather. Also, tires are subjected to flexing and impacts that can diminish air pressure. So, think in terms of refilling your tire just like you do your gas tank; actually that's a good reminder, refill your tires every other time you fill up at the gas station. That's the recommended interval. Another time to check air pressure is when the tires are rotated. Many vehicles have different tire pressures on the front and rear axle, so remember to have this adjustment made. Also remember to have the pressure in your spare checked. The space- saver type spare requires a much higher air pressure level than other tires and is virtually useless (due to overloading) at lower air pressure levels.
Where To Find Air Pressure Information
The correct air pressure may be found in the vehicle owner's manual or on the tire placard (attached to the vehicle door edge, doorpost, glove box door or fuel door). The placard tells you the maximum vehicle load, the cold tire pressures and the tire size recommended by the vehicle manufacturer. If you have trouble, see a local tire dealer for assistance; check our directory for the nearest Discount Tire or America's Tire store.
Another valuable resource is the Tire Load/Inflation Tables. Your nearby tire dealer should have a copy. Not only will this document tell you the correct tire pressure for stock sizes, but it will provide the information on optional plus sizes as well. A good example would be the findings on a Honda Civic with the stock size 185/65R-14; recommended air pressure is 28 psi. Plus one size is 195/55R-15 with a recommended air pressure of 32 psi. Plus two size is 205/45R-16 with a recommended air pressure of 36 psi. Note how the air pressure increases with plus sizing to meet the load carrying capacity for the car.
Other Factors Change Air Pressure
Besides the routine air check, other circumstances necessitate a visit to the air pump. Seasonal changes or altitude changes create a rise or drop in air pressure (for every 10 degrees change in temperature, tire air pressures changes 1 psi). But perhaps the most overlooked factor is vehicle loading for trucks and RVs. Since these vehicles can be configured and loaded in many ways, the proper inflation pressure should be determined by actual tire loads. This is best determined by weighing the vehicle; vehicle loading can change from trip to trip.
Remember that tire failure can occur due to under inflation and overloading!
One of the most dangerous conditions that can exist is the slow leak. Sometimes a small nail, screw or other object will puncture a tire and then act as an inefficient plug. Air pressure drops slowly over a matter of hours or days, undetected by the driver. Your best defense in this circumstance is to be alert to the symptoms of this. Be aware of any pulling or vibration that seems unnatural. And listen for any tick- ticking sound -- especially audible at slow, parking lot speeds. If you detect this, get off the road and inspect the tires on the side of the pull, vibration or sound. A bulging sidewall and/or excessively hot tire indicates a slow leak. Put on your spare tire and have your tire dealer repair the punctured unit. Ask the repair technician if any sidewall damage has occurred (a powdery residue inside the tire indicates this condition). If so, have the tire replaced.
How To Check Air Pressure
Properly checking tire pressure requires an accurate air gauge. Many people believe that they can check air pressure just by looking at the tire and judging the sidewall appearance. Also, many people use the air meters at service stations, which can be grossly inaccurate due to exposure or abuse. Invest in a quality air gauge. For trucks and RVs, use a dual-head inflation gauge that is calibrated up to 120 psi at 2 psi increments.
When checking your vehicle's tire pressure, make sure the tires are "cold". Cold air pressure means that the vehicle has not yet been driven one mile (remember that driving on a tire increases its temperature and air pressure). If you must drive more than one mile for air, check and record the air pressure in all your tires before you leave. Once at the tire dealer, measure each tire's inflation again and then note the difference. Inflate the tires with low pressure to a level that is equal to the recommended cold pressure plus the difference at the higher temperature.
In this example, add 3 psi in the right rear tire to match the other rear tire's warm reading. When the tire returns to cold pressure, it should end up at the recommended pressure.
Finally, after completing the pressure check, make sure the valves and extensions are equipped with valve caps to keep out dirt and moisture. Remember to replace the valve assembly when you replace the tire; it's your best assurance against a sudden or consistent loss of air pressure.
Environmental Impact
How can routine air pressure maintenance impact our environment? Consider that fewer tires per year would end up in the landfills and scrap heaps that trouble our ecology. How many tires are we talking about? We estimate that most drivers lose from 10% to as much as 50% of tire tread life due to underinflation. That's a significant statistic. Now consider the extra fuel we burn to push cars along on soft, underinflated tires. Tires do require extra energy to roll if they are under inflated. While the statistics vary widely and inconclusively, the implications are staggering. So maintaining tire pressure is a small line item in our busy daily routines, but it adds up to big environmental consequences. We must all care and take action to do the right thing.
Hope this info helps.
Here is some good info from Ingersoll-Rand on using Nitrogen:
Nitrogen Tire Filling. A competitive advantage.
Now, Ingersoll Rand offers you a choice. You can use nitrogen, not ambient air, to fill tires with the new Nitrogen Tire Inflation System. A revolutionary technology in tire inflation. You gain a competitive edge by enhanced tire pressure retention. Bringing tire inflation and, in turn, travel to a new level. Creating a new source of revenue for your business. Improving tire performance, road safety and cost savings for your customers.
Better air pressure retention. The single biggest reason for tire failure is lack of maintenance of tire pressure. In fact, 54 percent of all vehicles on the road have low tire pressure. Oxygen in compressed air can permeate the tire wall reducing tire pressure. With nitrogen, diffusion is 30 to 40 percent slower than oxygen. As a result, nitrogen maintains tire pressure longer than ambient air.
Enhanced fuel economy. Maintaining tire pressure can boost fuel economy by as much as 6 percent. Nitrogen disperses heat more quickly than ambient air. By restraining the heat in the tire and reducing rolling resistance, you get better fuel economy.
Longer tread life. With quicker heat dispersion, you get a cooler running tire which helps extend tread life and reduce tire failure. Nitrogen also prevents oxidation which can not only lead to tread separation and belt failure but, when combined with moisture, corrode rims. In fact, moisture can result in rust flakes that can fall into the valve stem, block the valve and cause under-pressurization. It can even cause the valve stem itself to rust.
Slow chemical aging. Filling a tire with nitrogen also significantly slows the chemical aging process of the tire’s rubber components. This leads to fewer catastrophic failures like blowouts. Slower aging lengthens tire core life, which yields extra retreads and lower fleet costs.
Here is a good page from the Discount Tire web site for tire pressure:
The Benefits of Correct Air Pressure
Keeping the correct air pressure in your tires is as important as giving your engine a tune up. The economic benefits are perhaps even greater! With the right amount of air pressure, your tires wear longer, save fuel, enhance handling and prevent accidents. If you consider the liabilities of not maintaining the correct air pressure -- poor gas mileage, loss of tire life, bad handling (perhaps even loss of control), and potential vehicle overloading -- then the need to routinely add air to your tires will become clearer.
Check Air Pressure Routinely
Perhaps because our tires do so much without seeming to need any attention, we tend to overlook this important task. But tires do lose pressure, slowly but surely everyday, through the process of permeation. Generally, a tire will lose one or two pounds of air per month in cool weather and even more in warmer weather. Also, tires are subjected to flexing and impacts that can diminish air pressure. So, think in terms of refilling your tire just like you do your gas tank; actually that's a good reminder, refill your tires every other time you fill up at the gas station. That's the recommended interval. Another time to check air pressure is when the tires are rotated. Many vehicles have different tire pressures on the front and rear axle, so remember to have this adjustment made. Also remember to have the pressure in your spare checked. The space- saver type spare requires a much higher air pressure level than other tires and is virtually useless (due to overloading) at lower air pressure levels.
Where To Find Air Pressure Information
The correct air pressure may be found in the vehicle owner's manual or on the tire placard (attached to the vehicle door edge, doorpost, glove box door or fuel door). The placard tells you the maximum vehicle load, the cold tire pressures and the tire size recommended by the vehicle manufacturer. If you have trouble, see a local tire dealer for assistance; check our directory for the nearest Discount Tire or America's Tire store.
Another valuable resource is the Tire Load/Inflation Tables. Your nearby tire dealer should have a copy. Not only will this document tell you the correct tire pressure for stock sizes, but it will provide the information on optional plus sizes as well. A good example would be the findings on a Honda Civic with the stock size 185/65R-14; recommended air pressure is 28 psi. Plus one size is 195/55R-15 with a recommended air pressure of 32 psi. Plus two size is 205/45R-16 with a recommended air pressure of 36 psi. Note how the air pressure increases with plus sizing to meet the load carrying capacity for the car.
Other Factors Change Air Pressure
Besides the routine air check, other circumstances necessitate a visit to the air pump. Seasonal changes or altitude changes create a rise or drop in air pressure (for every 10 degrees change in temperature, tire air pressures changes 1 psi). But perhaps the most overlooked factor is vehicle loading for trucks and RVs. Since these vehicles can be configured and loaded in many ways, the proper inflation pressure should be determined by actual tire loads. This is best determined by weighing the vehicle; vehicle loading can change from trip to trip.
Remember that tire failure can occur due to under inflation and overloading!
One of the most dangerous conditions that can exist is the slow leak. Sometimes a small nail, screw or other object will puncture a tire and then act as an inefficient plug. Air pressure drops slowly over a matter of hours or days, undetected by the driver. Your best defense in this circumstance is to be alert to the symptoms of this. Be aware of any pulling or vibration that seems unnatural. And listen for any tick- ticking sound -- especially audible at slow, parking lot speeds. If you detect this, get off the road and inspect the tires on the side of the pull, vibration or sound. A bulging sidewall and/or excessively hot tire indicates a slow leak. Put on your spare tire and have your tire dealer repair the punctured unit. Ask the repair technician if any sidewall damage has occurred (a powdery residue inside the tire indicates this condition). If so, have the tire replaced.
How To Check Air Pressure
Properly checking tire pressure requires an accurate air gauge. Many people believe that they can check air pressure just by looking at the tire and judging the sidewall appearance. Also, many people use the air meters at service stations, which can be grossly inaccurate due to exposure or abuse. Invest in a quality air gauge. For trucks and RVs, use a dual-head inflation gauge that is calibrated up to 120 psi at 2 psi increments.
When checking your vehicle's tire pressure, make sure the tires are "cold". Cold air pressure means that the vehicle has not yet been driven one mile (remember that driving on a tire increases its temperature and air pressure). If you must drive more than one mile for air, check and record the air pressure in all your tires before you leave. Once at the tire dealer, measure each tire's inflation again and then note the difference. Inflate the tires with low pressure to a level that is equal to the recommended cold pressure plus the difference at the higher temperature.
In this example, add 3 psi in the right rear tire to match the other rear tire's warm reading. When the tire returns to cold pressure, it should end up at the recommended pressure.
Finally, after completing the pressure check, make sure the valves and extensions are equipped with valve caps to keep out dirt and moisture. Remember to replace the valve assembly when you replace the tire; it's your best assurance against a sudden or consistent loss of air pressure.
Environmental Impact
How can routine air pressure maintenance impact our environment? Consider that fewer tires per year would end up in the landfills and scrap heaps that trouble our ecology. How many tires are we talking about? We estimate that most drivers lose from 10% to as much as 50% of tire tread life due to underinflation. That's a significant statistic. Now consider the extra fuel we burn to push cars along on soft, underinflated tires. Tires do require extra energy to roll if they are under inflated. While the statistics vary widely and inconclusively, the implications are staggering. So maintaining tire pressure is a small line item in our busy daily routines, but it adds up to big environmental consequences. We must all care and take action to do the right thing.
Hope this info helps.
Instructor
Joined: Sep 2006
Posts: 122
Likes: 0
Right you are Mike. My DIC reads 27 all the way around when the tire pressure is actually 30 PSI as measured with both a mechanical and digital gauge. Some forum members say that their DIC's are "right-on-the-money" reading 30 PSI with a measured tire pressure of 30 PSI. I don't know why there is such a variation in these sensors. They obviously have some degree of error but I have never seen a published specification on them. Anyway, the DIC to me is only a relative indication of air pressure.....my real concern is that amber tire light on the instrument panel.....LOL.
