How To Ensure That Your Tyres Are Properly Inflated
Car Care Tips And Tricks
Inappropriate tyre pressure can cause poor mileage, uneven tyre wear or in some cases a tyre blow-out. To prevent these events from happening it is important to maintain proper tyre pressure on your vehicle.
In some situations it is more beneficial to lower your tyre pressures such as when driving on sand because this provides better flotation by increasing the size of your “footprint” and thus dramatically improving your traction. It also reduces the amount of strain on your vehicle and minimises wear and tear on the tracks.
If you deflate your tyres for this purpose please remember to re-inflate them again!
Checking your tyres and ensuring that they are properly inflated is an easy process that you should be doing on a regular basis to ensure that your vehicle is always performing at it’s best.
Step 1: Locate an air station, these are usually found at most petrol stations and are free.
Step 2: Make sure that the tyres are “cold” (vehicle hasn’t been driven for more than 2kms) so the air in the tyres isn’t expanded from heat.
Step 3: Look in the owners’ manual or (on most vehicles) on the inside of the driver’s side door for the standard cold tyre inflation pressure. This number is the lowest PSI one would inflate the tyres to and is suggested by the car’s manufacturer.
Step 4: Check the air compressor / pump to ensure that the tyre pressure settings match the standard cold tyre inflation pressure for your vehicle. If it does not match then be sure to adjust the desired pressure in PSI. Use the options provided to confirm whether you want to obtain a pressure reading or inflate your tyre.
Step 5: Unscrew the valve stem cap from the valve stem on the tyre. The valve stem is a black pencil-sized extension near the hubcap, about 2-3 cms long.
Step 6: Locate the tyre pressure gauge and hose which is usually connected to the air station.
Step 7: Press the air pressure gauge onto the valve stem and record the reading given. If there is a hissing sound, the gauge is not tight enough for an accurate reading. The angle of the gauge may need to be adjusted.
Step 8: Note that if the reading is the same as the manuals’ specifications, you are done after checking all other tyres for the same pressure. If inadequate pressure is in the tyres then fill the air in the tyres by adjusting the options available on the air station. Make sure you put in the correct amount.
Step 9: Replace valve stem cap. The cap does not hold air in but it keeps dirt and moisture away from the valve mechanism in the valve stem, which does hold air in.
Step 10: For bonus points ensure that you put the air hose and gauge away neatly for the next user.
Some Additional Tips:
- Sunlight heats up tyres even if they’re not driven. For more even readings take note that not one side of the car has sun shining on it.
- Cold weather will reduce the air pressure, warm weather will increase the air pressure – it is important to recheck tyre pressure when the seasons change.
- The PSI listed on the sidewall of the tyre is the max cold pressure for the tyre carrying the highest (weight) load the tyre supports.
- Increase the cold tyre pressure if the car will be carrying a heavy load or driven at high speeds for long times.
- Additional fuel economy and improved steering response can be obtained at the price of a firmer ride if the tyre’s inflation is increased above what is recommended by the car’s manufacturer. This shouldn’t exceed the max pressure listed on the tyre’s sidewall. Test the car to see if its driving feel is improved.
- If the car has to be driven to add air note the pressure before driving away. Then add the difference above when the reading is now. For instance if you wish to inflate your tires to 35psi and they’re reading 30psi cold. The tires are 5psi underinflated so when you add air after driving and they now read 33psi adjust them to be 38psi. They should then read 35psi when cold.
- Tyres can not be “eye-balled” for pressure, particularly modern radials. Always use an accurate gauge.
- An under inflated tyre causes more sidewall flexing that increases stopping distance, lowers fuel economy and shortens the life of a tyre. In rare cases the tyre can blowout because of excessive heat from too much sidewall flexing and can even roll off the wheel in emergency maneuvers.
- An over inflated tyre (filled above the max cold pressure on the sidewall) makes for a harsher ride and makes it more prone to damage if you hit pot-holes or other objects in the road.
- Whilst the air pump gauge at the petrol station is free it is not necessarily the best source of air pressure readings. These pumps take a lot of abuse (slammed against concrete, ran over, etc.) and may not be calibrated properly…it is best to fill your tyre “above” the recommended PSI, using the gauge on their pump but then once done, check the tyres using “your” gauge. Always base your final readings using “your gauge” for best accuracy.