Tire Pressure Monitoring Systems (TPMS)
What Is TPMS
It is a system used to monitor the air pressure in the pneumatic tires on different kinds of vehicles. In other words, it’s a warning system which warns the driver of a dangerous change in the air pressure in one or more tires.
Pressure-sensing transmitters mounted in each tire record the readings. Each transmitter sends those readings to a central computer (ECU) which will display them on the dashboard. TPMS provides real-time tire-pressure information to the car driver, either via a pictogram display, a gauge, or a simple low-pressure warning light.
There are two major types of TPMS- direct (dTPMS) and the indirect (iTPMS). These systems are available both at an OEM (factory) level and an aftermarket solution. The primary target of TPMS is to avoid poor fuel economy, traffic accidents and increased tire wear because of underinflated tires through early recognition of a dangerous state of tires.
How Do You Know If Your Vehicle Has TPMS?
In the Canada, most cars or light-duty vehicles under 10,000 lbs, and manufactured after September 1, 2007, have TPMS. Also, some models made after October 5, 2005, might have TPMS.
Among other matters, within TREAD Act of 2000, the United States federal government authorized the necessary implementation of TPMS on all new vehicles as follows:
1. 20 percent of new vehicles from October 5, 2005, to August 31, 2006.
2. 70 percent of new vehicles from September 1, 2006, to August 31, 2007.
3. 100 percent of new vehicles from September 1, 2007, and beyond.
Also, before this legislation, some high-end vehicles came fitted with TPMS as a premium option.
There are numerous ways to determine if your vehicle has a TPMS. The easiest one is to check the owner’s manual or to watch the dashboard indicator at startup. Turn the ignition switch of your vehicle to “ON” or “AUX” position, or just start the car.
Why Does Tire Pressure Change?
Several factors affect the tire pressure including ambient temperatures and tire damage like punctures. For every 10o F drop in ambient temperature, the tire pressure drops nearly one psi. Besides, tires can lose up to 1.5 psi every month since air escapes the rim and the tire naturally.
How Often Should You Check Your Tire Pressure?
A tire can lose air even when it is not damaged or punctured. All tires lose air naturally over time. Therefore, it’s good to check your tire pressure, including the spare, are once a month.
Adverse weather conditions, road conditions or other conditions may warrant checking the pressure in your tires more regularly. You should always use a quality tire gauge to check pressure. Do not forget the spare! It may not have TPMS, but if you are checking your tire pressure, you should also check your spare tire.
As many motorists check their tires when problems occur and at service intervals, they can benefit significantly from the greater awareness of pressure in their tires and its effects on safety while driving.
The recent statistics from the National Highway Traffic Safety Administration (NHTSA) reveals that about 660 car accidents in the United States every year are caused by underinflated tires. Some of the problems caused by underinflated tires on dry or wet surfaces include:
1. Hydroplaning on a slippery surface that can cause skidding and loss of control.
2. Crashes from blowouts or flat tires.
3. Skidding or loss of control of the car when navigating any curve at high speed, or in a pronounced curve, like an off-ramp on a highway.
Benefits of TPMS
The inflation pressure of a pneumatic tire affects its dynamic behavior. Key factors such as lateral stability and braking distance require the stability pressures to be adjusted and kept at a level specified by the manufacturer.
Extreme under-inflation can even cause mechanical and thermal overload due to overheating and subsequent, impulsive destruction of the tire itself. Also, under-inflation can severely affect tire wear and fuel efficiency. Here are some of the major benefits of TPMS:
1. Extended tire life
Underinflated tires are the primary cause of tire failure and contribute to heat buildup, tire disintegration, sidewall/casing breakdowns and ply separation. Further, the pressure difference of 10 psi (0.69 bars; 69 kPa) on a set of duals literally drags a low-pressure tire 13 feet per mile (2.5 meters per kilometer)
Running a tire (even shortly) on insufficient pressure breaks down the casing and prevent the ability to retread. It’s good to note that under-inflation doesn’t cause all sudden tire failures. For instance, structural damages as a result of hitting sharp potholes and curbs can cause sudden tire failures even after the damaging incident. Any TPMS can’t detect these failures proactively.
2. Fuel Savings
According to the GITI, for every 10 percent of under-inflation on a tire, a 1 percent decrease in fuel economy will occur. In the US alone, the Department of Transportation estimates that underinflated tires waste two billion gallons (7,600,000 cubic meters) of fuel annually. Properly inflated tires will boost fuel efficiency.
3. Decreased maintenance and downtime
Underinflated tires lead to costly maintenance and downtime hours. With TPMS, these hours will reduce significantly.
4. Environmental efficiency
As estimated by the Department of Transportation, underinflated tires release more than 26 billion kilograms of carbon monoxide pollutants into the atmosphere every year in the US only. Vehicles equipped with TPMS hardly experience low air pressure in the tires.
5. Enhanced safety
Underinflated tires cause tire failure and tread separation, resulting in 40, 000 accidents, 33, 000 injuries and more than 650 each year. However, a tire inflated correctly add more stability, braking and handling efficiencies and offer greater safety for the driver and passengers, the loads, the vehicle and others on the road.
Can Having TPMS In Your Car Save Money?
Yes, a tire inflated will save a significant amount of cash at the pump due to enhanced fuel efficiency. Based on the statistics at FuelEconomy.gov, a joint website of the Environmental Protection Agency (EPA) and the United States Department of Energy (DOE), underinflated tires can reduce gas mileage by 0.3 percent for everyone psi decrease in all four tires. Furthermore, properly inflated tires last longer and are safer.
The EPA and DOE highlight that fuel economy has four significant benefits to you:
1. Saving money.
2. Enhancing energy sustainability.
3. Reducing climate change.
4. Reducing oil dependence costs and fuel consumption.
Did you know that about 3.5 million gallons of gas are wasted every day due to incorrectly inflated tires? The DOE asserts that drivers can improve gas mileage by nearly 3.3% by keeping tires inflated to the correct pressure. For many consumers, that represents about ten extra miles or more on each tank of gasoline.