THE TIRES FOR THE (REST OF) US
This article is from our archives and has not been updated and integrated with our "new" site yet... Even so, it's still awesome - so keep reading!
Published on Sun, Jul 19, 2009
By: The LACar Editorial Staff
THE TIRES FOR THE (REST OF)
By Zoran Segina
By Zoran Segina
Ask an average Southern California driver about the tire rating on his or her car, and you may get: "I dunno dude, PG-13?" Too much Hollywood, perhaps, but, most drivers around here act as though their tires are more of a nuisance then a vital part of the car. Every day you will encounter a car with a dangerously under-inflated tire, usually rear left. Remember the SUV rollovers? If you stop at a gas station to inflate your tires, good luck. The machine is usually stuck in the remotest corner of the station (in some cases on an incline), pulling a compressor hose can dislocate your shoulder, the hose is usually too short, the gauge is inaccurate, and the airflow will cut off just before the last tire. In a survey not long ago some California drivers stated that their tires have the same warranty as the car, and should be left alone for the first fifty thousand miles or so. And yet, our engines are getting more powerful, our cars more sophisticated, and our tires more advanced. The aspect ratios are decreasing, or put simply, the tires are getting wider and lower. Add to this improved grip, electronic stability controls and what not; and an average car driven by an average driver is handling better, and can be driven faster. Up to a point. Car racing aficionados know how much attention is paid to managing tires. The racing teams whose knowledge about handling and performance is beyond our comprehension treat tires with awe and respect because the only contact point between a multimillion dollar racing machine and the road are four pieces of rubber the size of a small notebook. These guys know that there is a physical limit to the best handling chassis, step over it, and, in a split second, the marvel of modern technology turns into a hunk of metal and plastic traveling (usually) in a straight line until making contact with the nearest obstacle. When this happens, the race car driver sitting behind the wheel has as much control as the guy watching the race on TV. With extensive racing training and experience a professional driver can feel this limit, and can counteract - with the right maneuver and lightning speed - to bring the car back within the handling envelope. A Los Angeles driver, having passed a driver's training that amounts to no more than a trip around the block, and an experience of daily commute to work on mostly dry freeways, does not have that feel, and is ill-equipped to handle a modern car that steps over its handling plateau. But what if there was a device to alert an average driver that a disaster is not far away? Sort of an automotive Jiminy Cricket to whisper in our ear, as we drive faster and faster. Enter Continental Extreme Contact DW. The Continental Corporation, one of the top automotive supplier of tires, brake systems, and other components, decided to build a tire for us - the North American market. Come on, we know they predominantly had Angelinos in mind. The ultra-high performance tires fit sixteen to twenty-one inch wheels with aspect ratios of 25-55. The tire has chamfered edges and a solid outer shoulder for enhanced performance on dry roads, dynamic temperature distribution for lower rolling resistance and improved tread-life, and high void-to-tread ratio with enhanced groove curvature to pump out as much water as possible when (if?) the rains come. The tire even comes with the DW Tuned Performance Indicators, visible letters built into the second rib of the tread to alert drivers of the tire's optimal performance levels. A letter "D" indicates the tread depth for dry conditions; "W" is for wet. Simple. So instead of trying to figure out how much of Lincoln's head still protrudes after you stuck a penny in the tire, when the indicators disappear the Contis are no longer tuned for optimum performance in that particular road condition. Translation - the baby needs new shoes. The speed rating for the Extreme Contacts is W and Y. The UTQG Rating is 340 AA A for ultra high performance and 540 A A for the all-season model. As to what this means - see below. In Germany, where Continental is based, there (still) exist no-speed-limit autobahns, so ratings were established to match capability of tires with the top speed capability of the vehicles to which they are applied. The tire is pressed against a large diameter metal drum and run at ever increasing speeds in time increments. The W equals the maximum top speed of 270 km/h (168 mph) while the Y pushes it to 300 km/h (186 mph.) At that point, at least in California, any excessive tire noise is drowned by the wail of police sirens and the staccato of helicopter blades. Uniform Tire Quality Grade Standards (UTQG) - created by the U.S. Department of Transportation (DOT) National Highway Traffic Safety Administration's (NHTSA) - provide information on tires' relative tread wear, traction and temperature capabilities. A traction test is a 7,200 mile run around a 400-mile loop in West Texas. The course monitoring tire is assigned grade 100). A 340 grade would indicate that the tread would last almost three and a half times as long as the test tire. A 540 grade indicates close to a forty thousand mile tread wear (5.4 x 7,200 = 28,800). For traction grades a properly inflated test tires are installed on a "skid trailer," and pulled behind a truck at 40 mph over wet asphalt and concrete. The brakes are momentarily locked, and the sensors measure the tire's coefficient of friction (braking g forces) as it slides. AA is the best followed by A, B, and C. The temperature grade indicates how well can a properly inflated tire dissipates heat while it runs against a high-speed lab test wheel. The tire unable to resist the heat buildup at high speeds will ultimately explode. The A grade tire can safely run at speeds of over 115 mph. The wail of police sirens and the staccato of helicopter blades also apply here. But all of this technical staff cannot describe how it feels to drive a car shod with the Continental Extreme Contacts DW and DWS. So, off we went, on a spring day, at the California Speedway in Fontana. Around the dry track, and wet track, and the oval, and the infield race track, and out on the streets, in European sedans, in American muscle cars, in Japanese compacts, in club racers, in go-carts, in SUVs, in American Le Mans series Porsche (this one, thankfully, handled by a professional), we drove, and were driven, in pretty much anything with four wheels and an internal combustion engine to compare the Contis against the competitors.
Chargers on Contis at California Speedway in Fontana As for the findings: the Contis worked really well on European sedans and the Japanese cars, less so on American muscle cars. On a twisty auto-cross track the Contis will start losing grip sooner than their competitors, but a decrease in grip comes gradually, so that a driver can take corrective action with plenty of time to spare. The braking tests and the grip test (driving ever faster around a big wet circle) showed that the new Contis are an exceptionally competent, and can instill in the driver an extra dose of confidence. The grip test also confirmed that no tire can prevent a spin if the driver pushes the car too far. The extra dose of confidence came in handy when we took the wheels of race prepared Toyota Celicas on the big banked oval in a "follow the leader" formation. At 75 (as in miles per hour) it was interesting, at 85 it became exhilarating, at 90 it got twitchy, and at 100 one developed a whole new perspective on oval racing, because how the heck do these guys go around at 185? A closer taste of what the real oval racing like came in the passenger seat of the ALMS Porsche, going around at about 150, and the concrete mass of the retaining wall getting closer and closer. . . . NASCAR describes the handling of a race car as "tight" and "loose." Or in this instance, as the Porsche got progressively looser, some of my body parts got progressively tighter. And so it went, all day. Continental also brought in two drivers from the Hollywood stunt school who demonstrated unbelievable car handling ability. With a proper equipment, and training, it is possible to parallel park the car by sliding it into a spot from the opposite direction - it is not all computer graphics. Remember however, the warning at the bottom of every TV commercial: "professional driver, do not attempt." The honorable mention deservedly goes to the In-n-Out Burger for mid-day catering, and the young hostesses from a modeling agency who stood on the tarmac braving overcast and cold morning skies and stiff breeze in visually appealing albeit thermally insufficient outfits. For you single guys out there: nothing will melt a pretty girl's heart faster than a warm jacket you wrap around her on a cold morning. That afternoon, on a street course around the Fontana raceway, we were comparing the same make and model of a car shod with two different tires. After few runs it was obvious that a tire choice significantly impacts handling and performance. The differences were immediate and dramatic. Certain cars, especially SUVs became practically impossible to drive when paired with a wrong tire. So, my dear fellow drivers, pay attention to your tires. Next time, bend down and look underneath your car, and you will see the four small rubber patches between the car and the road. If you happen to see anything else down there you may have to call a mechanic. Or a policeman. Or a lawyer. Or a . . . . . . . For more information about Continental tires, go to www.continentaltire.comÂ