A vehicle could be rightly likened to a human being. All the organs of the body must function properly to coordinate effectively in serving that body.
Similarly the vehicle has its various organs or parts that must be in healthy condition to make it roadworthy. And ROAD WORTHINESS of a vehicle is verified through its inspection by an approved authority that ascertains that a vehicle meets Road Safety and Environmental Standards.
In Nigeria, the Vehicle Inspection Officer (VIO) has maintained that a roadworthy vehicle shall have the following component parts in a satisfactory working order.
• Body and Vehicle Structure
• Exhaust System and Exhaust Emissions
• Fuel System
• Seats and Seat Belts
• Tyres and Wheels
• Registration Plates
• Boot/Tailgate and Bonnet/Hood
• Wipers and Washers
• Steering and Suspension
Tyres for the vehicles are like the legs and hands to the body of animals/humans. It is the mechanical movement of the tyres that led credence to the role of vehicle or usefulness to humanity.
The theme of this lecture is BE TYRE CONCIOUS: STAY ALIVE!
This is the truth because as a driver your life fides on your tyre every time you get into your vehicle Therefore, how do we eliminate fake tyres? Scholars and renowned mechanics and vulcanizers who are good in their craft believe it is done by good knowledge of tyre types.
Inspecting the tyres is serious business for all government agencies- from Custom Service, VlOs, the FRSC, Tyre Dealers and Sellers, SON and all other stakeholders in road safety measures. There is regular and continuous enforcement of the rule that all drivers should pay regular attention to these vital parts of their vehicles.
The following safety tips should be scrupulously adhered to in order to have a basic knowledge of tyres as concerned stakeholders.
1. Check tyre pressures and adjust at least once a month:-
According to studies conducted by the FRSC in Nigeria at its inception on tyre-related crashes, the leading cause of tiye failure is under-inflation.
Under-inflation can have many causes, including a gradual loss of pressure through membranes in the tyre itself. It is typical for pressure to drop in direct relationship with loss in temperature.
Under-inflation has immediate effects on vehicle handling (as well as fuel consumption), but its potential impact on overall safety and tyre life are even greater. It results in premature and uneven tread wear on the outer edges.
Under-inflation also increases stress on the carcass itself, through flexing and overheating, which can lead to structural failures such as tread separation. That’s why it is imperative to check and adjust tyre pressure at least twice a month and before every long trip in some vehicles.
Recommended pressures are printed on a label located on the driver’s doorframe or in the glove box.
2. Inspect tyres regularly for abnormal wear or damage:-
To ensure maximum tyre life and safety, give your tyres a visual inspection on daily basis and before long trips. This is easily done at the same time you check pressures.
Look for the following:
i. Excessive or uneven tread wear, which may indicate improper inflation or steering and suspension misalignment;
ii. Cracks or bulges on the sidewalls or tread;
iii. Chunking of the tread or any indication of tread separation from the carcass;
iv. Signs of puncture, or nails, screws, glass, pieces of stone or any foreign object imbedded in the tyre.
If you detect any of these conditions, take the vehicle in for further diagnosis immediately. In most cases, punctures can be repaired if their size is not excessive.
In general, external “plugs” are not recommended. Repairs should be made from the inside, and a complete inspection made while the tyre is off the rim. Sealing compounds and other emergency aids should be treated only as a means of moving the vehicle to a safe location for repair.
If abnormal tire pressure loss occurs, check the valve stems for leakage, as well as the tyre itself.
3. Rotate tyres every 6,000 miles or according to owner’s manual:-
Tyre rotation is essential to achieve even tread wear and maximum tread life.
On front-wheel- drive cars, for example, most of the braking, steering and driving forces are carried by the front tyres, which inevitably wear much faster.
A “cross-rotation pattern”—that is, moving the left-front tyre to the right-rear axle, the right- front tyre to the left-rear axle, etc.—can best balance tread wear and maximize tyre life That sequence can be performed on any vehicle equipped with four non-unidirectional tyres. Designated by an arrow on the sidewall, unidirectional tyres must be rotated only front to rear and rear to front, on the same side of the vehicle, so their direction of revolution does not change.
All-wheel-drive and four-wheel-drive vehicles are best suited to a lateral rotation —left to right and right to left—at the same end of the vehicle.
4. Maintain tires in proper balance:-Out-of-balance tyres can not only cause uneven tread wear and an uncomfortable ride but also excessive wear on the suspension and other components. An out-of-balance tyre can be detected by a severe thumping, usually most pronounced at highway speeds.
If such a condition occurs, have your tyres dynamically balanced as soon as possible. An experienced technician can usually determine which tyre is out-of-balance by driving the car.
Tyre balancing involves placing weights in appropriate places on the bead or inner circumference of the wheel.
Tyres should always be balanced when first installed, and whenever they are remounted.
5. Maintain steering and suspension in proper alignment:-Misalignment of the steering and suspension, front or rear, can not only adversely affect the steering feel and stability of a vehicle, but also cause rapid and uneven tyre wear. If not corrected, this misalignment can ruin a tyre in a short time and distance.
If you feel the steering “pulling” in one direction or another when traveling straight ahead on a flat road with no crosswind, or if you notice uneven wear on the tyres, particularly front tyres, you should have the alignment checked and adjusted as soon as possible.
Alignment should also be checked after a vehicle has been involved in a collision or if it is used continuously on rough roads, particularly those with large potholes.
6. Never overload a tyre:-
Overloading is the second leading cause of tyre failure, next to under-inflation.
All tyres are designed to operate within a maximum load range designated by a code on the tyre sidewall. Exceeding this can result in both excessive wear and reduced tyre life due to structural damage; including the potential for sudden failure.
In most vehicles, the maximum passenger and cargo load for which the vehicle and tyres are designed is printed on the same label that designates recommended tyre pressures. That load, particularly in the case of trucks and SUVs, may be substantially less than the vehicle is physically able to contain.
It is critical that the maximum allowable load never be exceeded. When determining the actual load in your vehicle, don’t overlook the tongue-weight of a trailer if you are trailer towing, since it also acts directly on the vehicle’s tyre.
7. Avoid overheating tyres:-
Heat, like load, is the enemy of tyre life.
The higher the heat it is subjected to, the shorter the tyre’s life; in terms of both treads wear and structural resistance.
High speeds, high loads, under-inflation, coarse pavement or concrete, and aggressive driving, including high cornering loads and hard braking, all contribute to high tyre temperatures. Combined with high ambient temperatures and continuous use, they can create extreme circumstances and cause sudden tyre failure.
To maximize tyre life and safety, therefore, it is important to minimize the simultaneous occurrence of such conditions. Be particularly vigilant at high temperatures and adjust your driving style to consider its effect on tyre life and performance.
8. Replace tires when required:-
Your vehicle’s tires should be replaced if:
i. Any portion of the tread is worn to the “wear indicator bars” or to a depth, as measured in a groove, of l/16th inch or less.
ii. Tread wear is severely uneven (in which case have the wheel alignment checked) or the center is worn much more than the edges (be more vigilant about tire pressures).
iii. The tyre sidewalls are severely cracked or there are bulges anywhere on the tyre.
iv. There is any indication of tread separation from the tyre carcass.
v. The tyre has been punctured and cannot be satisfactorily repaired.
There are other reasons you may need new tyes, as well. If you have been running on winter tyres, then a change is in order in the spring. Using snow tyres on dry roads accelerates their wear significantly and diminishes both traction and handling ability.
9. Install tyres in matched pairs or complete sets:-
Installing different tyes on the left and right sides can significantly upset the handling balance of a vehicle. For that reason, it is imperative that tyres be installed in front or rear pairs, or complete sets.
Those pairs should be the same construction, size, brand and type, with approximately the same tread wear. In most cases, if you have to buy one new tyre, you should buy a pair. It is essential that side-to-side pairs be the same and highly desirable that front and rear pairs also be matched, except in cases such as high-performance cars with larger tyres in the rear.
If you replace only two, the new tyres should generally go on the rear wheels, regardless of whether the vehicle is FWD, RWD, or AWD.
It is important to maintain maximum traction at the rear wheels to ensure stability. Putting new tyres on the front and nearly worn-out tyres on the rear wheels of any vehicle is a recipe for instability. It is thus very important to avoid dramatic differences in tread wear, front-to-rear.
Under no circumstances should you have tyres of different construction (radial and bias ply) or different classification (all-season and winter) on opposite ends or sides, since handling can be adversely affected.
10. Select the right tires for your vehicle and driving environment:-
Recent improvements in “all-season” tyres have substantially advanced the concept of one- tyre-for-all-needs. On the other hand, more specialized tyres than ever are now available for high performance, rain, snow, ice, off-road and touring. Some are even uni-directional, “run- flat” and even “green.”
Most drivers are happy just to know they have “all-season” tyres, and that is the way most new vehicles are equipped. These are a benign compromise, sacrificing exceptional capability in any one area of performance for acceptable capability in all.
Within that premise, however, there are huge variations in actual performance. Unfortunately, factors that improve one tyre characteristic tend to diminish another. For example:
i. A wide tread with minimal grooving may enhance dry grip, but detract from traction in wet and snowy conditions;
ii. An aggressive, open tread may enhance snow traction but aggravate tyre noise and sacrifice tread life on pavement.
In addition to dry asphalt, tyres may be expected to function on mud, snow, ice, sand or gravel, in temperatures from above 140°F to below -40°F.
You get some idea of the multiple trade offs designers have to make.
Just consider that exceptional virtues are probably achieved at the expense of others.
Determine what your primary needs are, and narrow your choices accordingly. Then, if possible, drive a similar vehicle equipped with the tyres you are considering.
(A PAPER PRESENTED BY YEMI ADEBIYI AT THE 2ND ANNUAL AUTO TYRE SAFETY DAY ON 3rd OF SEPTEMBER 2014 AT MILE 2 INTER-STATE PASSENGERS LOADING BAY, LAGOS-BADAGRY EXPRESSWAY, LAGOS, NIGERIA)