Driving/Maintenance/Brake and tire selection
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Brake and tire selection plays a large role in vehicle handling, stability, stopping power, and safety. High-friction brake pads, functional brake fluid, and enhanced brake parts can bring the wheels to a faster stop; poor tires however will not provide enough traction for the car to stop under load, or make tight and complex maneuvers. Because of the involvement of both brakes and tires in accelerating, maneuvering, and braking, both must be of high quality for the operating conditions the vehicle will experience.
The entire brake system must support braking for the operating conditions the vehicle will experience. High-performance brakes for street driving, for example, will overheat and fail on the race track; while rally brakes intended for extreme conditions need to warm up before providing any significant braking force, and won't stop a vehicle as well as the lowest quality street brakes if not heated to temperatures experienced while racing.
Brake pads, for disc brakes, come in a variety of materials for varied applications. They mainly generate heat through friction, siphoning momentum to do this, slowing the car down. Because of this, hot brake pads do not function very well, and the brake system must get adequate cooling to remove the energy completely from the system, thus slowing the vehicle down.
Brake pads must always match their intended use. High-performance pads for the proper application must be fitted to the car; pads for alternate applications do not function as well, and sometimes outright fail under stress. For example, metallic race brakes will provide little stopping power when pulling out of a driveway in the morning; ceramic street brakes will outright explode under the stress generated at 160mph on the race track.
Brake pads commonly use a few specific material types, although others exist. These mainly tune towards one application; however, specialized race brakes that still supply excellent grab in standard driving conditions do exist, and are a viable option for a weekend-racer daily driver. Some common material types are listed here.
- Organic - Street-ready brakes that supply decent grab in standard driving conditions.
- Ceramic - Street-ready brakes that supply excellent grab in standard driving conditions. Often mixed with copper filings, ceramic brakes provide low-noise, low-dust, high-performance operation.
- Semi-metallic - Typical material for racing brakes.
- Metallic - Another typical material for racing brakes, used in high-temperature, high-stress applications.
When considering brake pads, don't forget to consider the fluid. Brakes remove heat through rotors, calipers, and brake fluid lines; if the brakes get hot, they'll boil brake fluid, and then the vehicle won't stop. In general, you can always use a similar brake fluid of a higher rating, for example synthetic DOT5 hydraulic fluid in a DOT3 system, regardless of application. You should avoid using different fluids, for example silicon DOT5 in a mineral oil hydraulic fluid DOT5 system. A higher DOT rating means the fluid will boil at a higher temperature, allowing the brakes to get hotter before failure.
The selection of tires used on a vehicle controls its traction with the road in various conditions, which has a primary effect on its handling, braking ability, and general safety. Poor quality tires or tires designed for the wrong season will supply little traction, causing the driver to lose control of the vehicle under sever or even moderate handling stress and increasing braking distance. In some conditions, steering and braking can become entirely impossible. Because of this, tire selection is one of the most important decisions a driver must make; even with failed brakes, a driver can steer a vehicle off the road.
Sites such as Tire Rack and Tire Monkeyprovide reviews and traction ratings for various tires. This allows the driver to research the wet, dry, snow, and ice traction of tires; as well as hydroplaning resistance, ride comfort, general handling, and tread wear.
Various driving conditions pose various stresses on tires. In general, there are two major driving conditions a driver must consider: Summer and Winter. These conditions correspond to weather conditions in moderate-climate environments. In some cases, a driver may have to drive Off-road, or on Unpaved roads such as dirt or gravel roads, both requiring specialized tires and vehicles.
In Summer driving conditions, the weather stays relatively warm. At times the road will be quite dry and smooth; at other times, very wet. Summer tires must have a number of traction features to cope with these variations. They must have excellent wet and dry traction to cope with both rain and dry land well. They must also resist hydroplaning: Many tires will handle on wet road excellently, but ride up onto the surface of the water under enough force; tires which resist hydroplaning will do this briefly or not at all, quickly plowing down through the water's surface to reach solid road.
In Winter driving conditions, the weather stays cold. Winter tires must meet much more demanding performance specifications because of the varied conditions cold weather causes. For example, dry road may have a layer of salt, powdered snow, or even patches of ice on it. The road may have a thin or thick layer of dry, soft snow; it may have a coating of hard, compacted snow; it may have a mixture of snow and water, creating slushy and icy situations. Wet-traction tires won't deal with any of these; and tires that can deal with watery slush may not channel water away in the rain, but in the winter season they won't need to very often.
In Off-road conditions, the tires will encounter mud, dirt, gravel, rocks, grassy wooded areas, and the like. Off-road vehicles have greatly upgraded suspension systems to handle this sort of stress; they require special tires that can bite through mud and into dirt. Such tires likely won't resist hydroplaning or get as much traction in the rain or snow as Summer or Winter tires.
Unpaved roads demand completely different considerations. Dirt roads require more of an off-road tire with bite on dirt and mud. Gravel roads are dirt roads covered in loose rocks, requiring more driver care and tires that can shift most of the loose rocks out of the way for decent bite against something solid. Unpaved roads do not allow for great acceleration, sharp handling, or fast braking; tire consideration is less significant, but still important.
Summer, Winter, and All-Season
In typical conditions, drivers will see either Summer or Winter conditions; other driving conditions are more specialized and localized either to sport driving or small, undeveloped localities. This leaves the driver with the task of selecting between not only Summer or Winter tires, but also All-Season tires which supply good handling in all conditions.
All-Season tires compare favorably with Summer and Winter tires in all conditions; however, specialized tires may perform better. For example, Goodyear Assurance TripleTred all-season tires supply better summer handling than Michelin X-Ice Xi2 studless winter tires, but not as good snow and ice handling. Bridgestone Potenza RE050A Pole Position tires supply excellent dry traction and almost as good wet traction as the TripleTred tires, but virtually no traction on snow and ice.
Another consideration for specialized tire selection is tire performance over wear cycle. The Michelin X-Ice Xi2 tires, and other similar studless winter tires, loses its snow handling capabilities as the tread wears. Using these tires as All-Season tires would cripple them for winter conditions. Other snow tires may simply not have decent hydroplane resistance, or barely decent dry handling, rather being designed to give some traction in the snow; these such tires cannot safely be used in the summer.
In general, for areas which have a mild Winter season and experience mostly dry, non-icy conditions, decent dry-traction All-Season tires provide the greatest balance. All-Season tires will provide viable traction for the five days a year it actually snows, if driven with care. By contrast, for drivers in a hotter climate area such as California, Florida, or New Mexico, summer tires provide the best performance year-round; and in a snowy climate such as Alaska or Siberia, winter tires are basically essential.
Many areas experience both a mild summer and an active winter season. New York, Connecticut, and various parts of Europe all experience a warm summer season and a winter season with plenty of light or deep snow, ice, and slush. For these, the advantage of proper Winter tires definitely justifies having them; but proper Summer tires are necessary as well. Drivers in these areas should get a second set of wheels and equip them with proper Winter tires. During the Summer season, vehicles should use good Summer or All-Season tires; when it begins to snow, the driver should jack the car up and change all the tires for Winter tires. A cheap impact wrench will make this a half-hour job.
- Never buy retreaded tires or bargain-brand cheap tires.