Nexen Tire is a tire manufacturer, headquartered in Yangsan, South Gyeongsang Province, and Seoul, both in South Korea. Its major domestic competitors are Hankook Tire and Kumho Tires. The company’s name is reflected in the company slogan, “Next Century Tire.”
Premiere, N2000, N3000, N5000, and more than 30 other passenger car and light truck tires.
Tire rotation or rotating tires is the practice of moving automobile tires from one wheel to another to ensure even tire wear. Tire wear is uneven for any number of reasons. Even tire wear is desirable to maintain consistent performance in the vehicle.
By design, the weight on the front and rear axles differs which causes uneven wear. With the majority of cars being front-engine cars, the front axle typically has more of the weight. For rear wheel drive vehicles, the weight distribution between front and back approaches 50:50. Front wheel drive vehicles also have the
differential in front, adding to the weight with a typical weight distribution of no better than 60:40. This means, all else being equal, the front tires wear out at almost twice the rate of the rear wheels, especially when factoring the additional stress that braking puts on the front tires. Thus, tire rotation needs to occur more frequently for front-wheel drive vehicles.
Turning the vehicle will cause uneven tire wear. The outside, front tire is worn disproportionately. Cloverleaf interchanges and parking ramps turn right in right hand drive countries, causing the left front tire to be worn faster than the right front. Furthermore, right turns are tighter than left turns, also causing more tire wear. Conversely the sidewalls on the right tire tends to be bumped and rubbed against the curb while parking the vehicle, causing asymmetric sidewall wear. The symmetric opposite occurs in countries that drive on the left.
In addition, mechanical problems in the vehicle may cause uneven tire wear. The wheels need to be aligned with each other and the vehicle. The wheel that is out of alignment will tend to be dragged along by the other wheels, causing uneven wear in that tire. If the alignment is such that the vehicle tends to turn, the driver will correct by steering against the tendency. In effect the vehicle is constantly turning, causing uneven tire wear. Also, if a tire is under or over-inflated, it will wear differently than the other tires on the vehicle. Rotating will not help in this case and the inflation needs to be corrected.
Manufacturers will recommend tire rotation frequency and pattern. Depending on the specifics of the vehicle tire rotation may be recommended every 12,000 km (7,500 mi). The rotation pattern is typically moving the back wheels to the front and the front to the back but crossing them when moving to the back. If the tires are unidirectional, the rotation can only be rotated front to back on the same side of the vehicle to preserve the rotational direction of the tires. Most unidirectional tires can be moved from side to side if they are remounted; tires with asymmetric rims are a rare exception. More complex rotation patterns are required if the vehicle has a full-size spare tire that is part of the rotation or if there are snow tires.
Current thinking stresses the desirability of keeping the best tires on the rear wheels of the vehicle, whether it is front or rear drive. The reason for this is that if the rear wheels lose grip before the front ones, an oversteer condition will occur, which is harder to control than the corresponding understeer which will happen if a front wheel is lost. This is also the case if a tire blows out, so the intuitive belief that the front steering/driving tires need to be the best quality is not actually the case.
In rare cases, automobile manufacturers may recommend performing no tire rotation at all (eg BMW MINI).
The Light and the Dark is the fourth novel in C.P. Snow’s Strangers and Brothers series. Set in England in the lead-up to and during World War II, it portrays Lewis Eliot’s friendship with the gifted scholar and remarkable individual Roy Calvert, and Calvert’s inner turmoil and quest for meaning in life. Calvert was based on Snow’s friend, Coptic scholar, Charles Allberry. Their relationship is developed further in The Masters.
The novel portrays the tensions surrounding the build up to war and the sense of catastrophe so widespread in the 1930s.
Kumho Tire Co, Ltd. , formerly known as Samyang Tire, is a South Korean industrial conglomerate (”chaebol”) headquartered in Seoul, South Korea. Kumho means “bright lake” in Korean. It is a subsidiary of the Kumho Asiana Group, as is Asiana Airlines, Korea’s second largest airline.
It runs three manufacturing facilities in South Korea and three in China. Kumho Tire exports tires from Korea and China worldwide and has a global network of sales organizations. It has three centers for research and development, with the largest in Gwangju, South Korea. The others are in Akron, Ohio, USA and Birmingham, UK, and service the US and European tire markets respectively. The company manufactures a full range of tires under the Kumho and Marshal brands.
Snow chains, or tire chains, are devices which are affixed to the wheels of vehicles to provide superior traction when driving through snow and ice. Snow chains are usually attached to the drive wheels of a vehicle (e.g. the front wheels on a front-wheel drive car), though all four wheels may be chained to provide extra stability. Some owner’s manuals for four-wheel drive cars specify that two specific wheels can be chained, leaving the other two unchained if necessary.
Snow chains are paired into 2 sets of chains. You should buy chains that match your tire size (tire width and radius numbers can be found printed on the tire).
A set of chains are placed on the wheels that are connected to the drive train in order to gain traction in icey, snowy or muddy conditions.
Front Wheel Vehicles:
Most passenger cars are front wheel powered vehicles, so the snow chains would be placed on the 2 front tires.
Rear Wheel Vehicles:
Pickup trucks and older cars are usually rear wheeled drive so the chains are placed on the rear tires.
4 Wheel Vehicles:
4 wheel vehicles can use 2 sets of chains on all 4 wheels. With only 1 set of chains they are often put on the rear wheels, but can be placed on the front wheels instead for the added steering benefit.
In snowy conditions, transportation authorities often require snow chains to be fitted on vehicles that lack four-wheel drive and proper tires. These requirements are usually enforced by checkpoints, before which eligible drivers must have snow-chains fitted on their cars. Near such checkpoints, chains can often be fitted professionally for a fee. Snow chains limit the speed of the automobile to approximately 30 mph (50 km/h), but in deep snow the chains can be very useful.
Purchasing the right size chains for your tires
U.S. tires have standardized sizing information. This information can be found on the sidewalls of the tires. The first letter(s) is for the vehicle type, P for passenger, LT for light truck. The next 3 digit number gives the tire’s width in millimeters. The next 2 digit number gives the tire’s height to width ratio. The next letter is R, which stands for radial ply tires (not radius) followed by the last 2 digit number, which is the rim diameter for the vehicle’s wheels.
A windrow is a row of cut hay or small grain crop. It is allowed to dry before being baled, combined, or rolled. For hay, the windrow is often formed by a hay rake, which rakes hay that has been cut by a mower into a row. For small grain crops which are to be harvested, the windrow is formed by swather which both cuts the crop and forms the windrow.
The term may also be applied to a row of any other material such as snow[1]. In the case of snow, windrows are created by snow plows as they plow streets. The windrow may block driveways. Some municipalities have windrow removal service where a smaller plow goes to each individual driveway to clear the windrow. Most cities simply make the home owner clear the windrow to their own driveway.
A few cities will plow the windrow to the center of the street, blow the snow into trucks, and haul it away. Windrows made of snow are also called berms or more commonly, snow banks.
A windrow can also be the build-up of material on the edge of newly graded earthworks and dirt roads, or it can be a heap of road-building material laid down by a dump truck for collection by a paving machine.
Windrows of seaweed etc also form on the surface of lakes or seas due to cylindrical Langmuir circulation just under the surface caused by the action of the wind.
Windrows are often used in large scale vermicomposting systems.
Tire load sensitivity describes the behaviour of tires under load. Conventional pneumatic tires do not behave as classical friction theory would suggest. Friction theory says that the maximum horizontal force developed should be proportional to the vertical load on the tire. In practice, the maximum horizontal force Fy that can be generated is proportional, roughly, to the vertical load Fz raised to the power of somewhere between 0.7 and 0.9, typically.
Production car tires typically develop this maximum lateral force at a slip angle of 6-10 degrees, although this angle increases as the vertical load on the tire increases. Milliken, W.F., Milliken, D.L., 1995, “Race Car Vehicle Dynamics”, Society of Automotive Engineers (SAE) Warrendale, PA. page 27. Formula 1 car tires may reach a peak sideforce at 3 degrees Wright P., 2001, “Formula 1 Technology”, Society of Automotive Engineers (SAE) Warrendale, PA.
As an example, here is data extracted from Milliken and Milliken’s “Race Car Vehicle Dynamics”, figure 2.9:
| Vertical load | Fy/Fz | Slip Angle |
| (lbf) | max | degrees |
| 900 | 1.10 | 5.6 |
| 1350 | 1.08 | 6.0 |
| 1800 | 0.97 | 6.7 |
The same sensitivity is typically seen in the longitudinal forces, and combined lateral and longitudinal slip.
The Treadwear Grade of a tire is the numeric portion of the Uniform Tire Quality Grade Standards (UTQG) that are printed on the sidewall of a tire. These standards were enacted by the National Highway Traffic Safety Administration (NHTSA), which is part of the United States Department of Transportation. Higher treadwear numbers indicate that the tread of a tire, and hence the tire itself, should last longer, although this is more true within a single product line than when comparing the product lines of different manufacturers.
The wear on tires that are being tested (”candidate tires”) is compared to the wear of Course Monitoring Tires (CMT), which are sold by the NHTSA at its UTQG test facility in San Angelo, Texas. Both types of tires are mounted on vehicles that will be driven in a convoy during the test, thus ensuring that the candidate tires and the CMT tires experience the same road conditions. The convoy, typically one of four or fewer vehicles, will drive 7200 miles on public roads in West Texas. Candidate tire wear will be checked during and after the test, and compared to the wear on the CMT tires from the same convoy.
The first CMTs were commercially-available Goodyear Custom Steelguards, and Goodyear Tire and Rubber Company produced all CMT tires from 1975 until 1984. From 1984 to 1991, the CMT tires were produced by Uniroyal. CMT tires are now “specially designed and built to American Society for Testing and Materials (ASTM) standard E1136 to have particularly narrow limits of variability.” 1.
The treadwear grade describes how long the tire manufacturer expects the tire to last. A Course Monitoring Tire (the standard tire that a test tire will be compared to) has a rating of “100″. If a manufacturer assigns a treadwear rating of 200 to a new tire, they are indicating that they expect the new tire to have a useful lifespan that is 200% of the life of a Course Monitoring Tire.
The DOT does not test tires. It depends on manufacturers to test their own tires and report the results. Unfortunately, this system has made treadwear ratings far less useful than the DOT had originally intended because tire manufacturers are able to use the treadwear grade as a marketing tool.
It is legal and permissible for a manufacturer to give their tire a 240 rating when their competitor’s equivalent tire has a 220 rating; thus creating the false impression that the 240 tire is a better purchase because it will last longer. This tendency to inflate treadwear numbers has become so common that some manufacturers may report that ALL their tires have above average treadwear grades. Some are taking normal tires and reporting a treadwear of 600 or more, or giving a 220 rating to maximum performance tires with a reputation for poor tire life (e.g. the Goodyear Eagle F1 Supercar EMT).
TreadWear Grade
Below 200=15% of Tires
201 - 300=25% of Tires
301 - 400=32% of Tires
401 - 500=20% of Tires
501 - 600=6% of Tires
above 600=2% of Tires
Source: safercars.gov
In general, manufacturers tend to overstate the treadwear of their tires in an effort to create the impression that their tires last a long time. The exception to this is in competition racing tires, which customers expect to have very soft rubber compounds and very short lifespans. Manufacturers tend to give their race tires low treadwear numbers (often zero) to emphasize how soft and sticky their rubber is.
The ability of manufacturers to report their own numbers makes comparison of treadwear ratings between companies useless. Ratings may still be useful within a manufacturer’s own line of tires. For example, a customer can reasonably assume that the higher treadwear rating on a Dunlop SP 60 means it will last longer than the Dunlop SP Sport.
Meltywax was a brand of wax produced using melting snow. It was shortly available in New England in the early 1920s but was removed from the shelves pretty quickly since it never managed to prove the melting snow had any noticeable effect on the quality of the wax. Therefore the interest in the product shortly decreased and the company went bankrupt in 1924.