eliminated) by parking in the shade and by using different kinds of materials on the tires’ sidewalls.
2. Oxygen and Ozone: Ozone is a heavy Isotope of oxygen which appears around electric circuits and in tropical areas. The effect of oxygen always exists and it also exists inside the tire.
3. Pollutants: Pollutants in the air, including carbon monoxide, fuel drops and dust contac the tire and destroy it’s molecules, making the rubber soft. Dust and such dirt enter the existing aging/weather cracks and effect the tire ever more dangerously. With stored or unmoved tires, the dirt often hosts insectoids that make the wear more grave.
4. Temperature changes: The constant changes of temperatures while driving, during the movment relative to the sun, over the day and during the whole year, make the tire heat up and cool down (“heat cycle”). The heating rubber expands and contracts again when it cools down. The problem is that eventually some of the elastic qualities are lost during this repititive process.
Another problem is that the tire is made of several rubber compounds, as well as a series of internal layers of steel, hard rubber, polyester and other substances. The result is that each layer expands at a different rate and they end up seperating. Another reason is airosion and lost of the anti-oxidants, anti-ozonants, anti-radiants and carbon black inside the tire. The front wheels are also effected by the engine’s heat on the inside shoulder.
5. Strain: The flex of the rolling tire makes the rubber, as it dries, to crack. Wear and abrasion occur on the outside, lateral and downward load deepen the cracks and the contact with objects on the road also effects the tire.
6. Moist and wetness also cause swelling of the rubber, lost of elastic properties and deepens the cracks. Salt in the air around the sea also causes this effect. This effect is all around the tire, including on the inside.
Many materials supposed to make tires shine don’t do the job quite right. Many of them are oil-based and might cause the tires to deteriorate, but some of them can be helpful. If you want, you can make a cheap, home-made liquid that can be used at least on the tire’s outside sidewall once every three weeks, to reduce weather cracking:
Mix hot water with some fresh lemon juice, a bit of vinegar, sylicon from some kind of gel or blam and a bit of olive oil. A bucket of water with two spoons of juice, two spoons of vinager and one spoon of olive oil, a bit of sun screen and 1/4 cup of said sylicon — clean the tire and than rubb this mixture onto the outer sidewalls and maybe inside the tread challens (not on the rubber that’s supposed to touch the road!).
Whenever using any kind of tire shine material, note that the tire aging process is not necessarily going to be very profoundly influenced. The gloss might keep it looking shiny, where in fact the tire might be extremlly aged, and don’t forget that the tread ages too. If carefully taken care off, the tires could live a bit of over four years, or 5.5 years in countries with colder weather. So, the suggestion to replace tires once every three to four years remains, but with a good treatment, the tires can maintain their original properties longer across the given service period, improving safety.
Rubber is a polymer, i.e. a long chain or macro-molecules that interconnect in a three-dimensional space, with the aid of special adhesives. When heat and Ionazing radiation (UVB and UVA) hit the surface of the polymer, they cause the solvents and adhesives to dissolve in a chemical process of defusion. The lost of those chemical agents, along with the heat, makes the polymer molecules generate new connections that might create a chemical shear that could tear them apart. Sylicon can filter out some of the sunrays and the UV, while reducing the heat and contact with moist and oxygen, and preventing some of the solvents from escaping.
Just as important as tire wear is tire pressure. Modern Radial tires are not as sensitive to under-inflation as bias-ply tires. Having said that, it’s importance is still very large, and is just important as having new tires. Tires naturally lose air at an average rate of 2PSIG per month, but that’s just an average, low quality tires will lose even more on some tires, and especially in hot summer conditions, and in the front wheels which are effected by the heat of the engine and it’s load. So the recommendation to check air pressure once a month is not a very good one. Air pressure should be checked once every two weeks. This would also make the required “tweaks” for the pressure to be little, so it can be done faster than it takes to refuel the car. The pressure should be checked and inflated on cold tires, and with a reliable pump and gage.
Finding the manufacturer’s specifications of air pressure can be quite an expedition in times: The sticker can appear on the B-pillar on both front doors (below window height) or on the door frame itself in about that height, or even on the A-pillar when the door is opened. It might appear under the hood itself or likewise in the trunk. They might appear on the gas tank cover (in German cars) or in the glove compartment, as well as over the wheel-arches and inside the car’s handbook. Trust those specifications and not the ones that might appear in the gas station. If you cannot find it (the sticker might fall off) look at an identical car or use google. It’s worthwhile to know that modern light automobiles operate at around 30PSIG.
A change of even two-three PSIG can facilitate a subtle but noticable difference, and make dramatic changes to tire wear on long highway drives. A seemingly small change of a reduced inflation by 20% can be classified as dangerous, because the car’s stopping distance, wear and chance of failure increase by about the same amount. In wet surfaces there is less wear, but the grip levels and stopping distance are reduced far more drastically than on the dry. Under such under-inflation, tires can be seen deforming laterally even in slow cornering, where any attempt to approach the limit will make the tire distort extremlly, leaving not one or two milimeters of rubber between the rim and road. Think about it, a tire deforms between 20 to 200 million times!
When tires are driven or even exposed to hot sun, they heat up and the air inside them expands. A tire with 28PSIG might show a reading of 30PSIG, and you might think it’s well-inflated, where in fact it is still under-inflated! It’s important to estimate the heat in the tire. After ten minutes and/or two kilometers of driving in the sun at even 50km/h (30mph), your tires might be warm enough to require an extra 5% of pressure. If you drive for 15 minutes you will need an extra 10%. 20 minutes of high-speed driving can increase the air by 15%, and 20% after half a hour, and even more in a hot day. Usually, an 10% addition solves the dillemas. The heat in the tire can felt by putting the back of your hand on the sidewall of the tire, near the tread. Don’t expect the front and rear tires to heat up symmetrically.
A tool that can help you is a personal tire gage. The cheapest and most simple is the pencil gage. It is a simple device made of a one-way pressure valve leading into a vacuum-chamber connected to a spring. You can easily find and purchase one in a very cheap price, with a pressure reading range of up to 40 to 60 PSIG. This kind of gage will be accurate down to about 0.5 of a PSIG, and be resistant to blows and shocks, unlike digital gages and dial gages. The most effective gage is a 0 to 60, oil-filled, rubber-encased dial gage.
This kind of gage enables to measure the air pressure at home and follow the changes when the tire heats up. Also, it enables to confirm the readings of the gas station pump, especially an analog pump with a handlebar, although it’s recommended to ensure that the pump is doing a good job if it’s a brand new digital one. They are often neglected, knocked about, and suffer from bad filtering, misfire in the electric engine, bad lubrication, and other problems that make it “miss” the right pressure.
Effects of under-inflation
The underinflated tire becomes softer and generated a wider profile. However, the softness makes it fold in the center of the tread, lifting parts of the tread off of the pavement. The center of the tread is more durable, grippy and is better in draining water. It is also directly responsible for accelerating and slowing down the car, so under-inflation dramatically increases stopping distances. The effects become much more acute in the wet, where the folds catch water inside them and make the tire skim and “hydroplane” very easily. The tread blocks twist and close up and the tire recieves a concave shape that disables it’s ability to penetrate the layer of water.
The car’s cornering is also compromised, because the softer tires is pushed by side forces so the sidewall cramms towards the outside of the corner, and twists the tire. This increases wear and, under severe under-inflation, can be heared as lound screetches (under-inflated tires are more loud). Slight under-inflation improves ride comfort, but the effect is bearly felt. Beyond that point the tire becomes too thin and cannot dampen bumps, and the narrow tread creates little turbulances of air, that generate more tire noise.
The tires generate more heat, and are in a risk of blow-outs, and slide earlier, albeit more progressively, but with less control over the slides, due to the sideways distortion of the sidewall. They increase wear on other car parts like brakes, drivetrain and steering linkages. Underinflation is useless, save in very specific situations of off-roading and even than the inflation should not be reduced by more