The U.S. motoring public's thirst for performanceexemplified by the resurgence in interest in muscle cars, hot hatches and tuningis reflected in an accelerating shift to performance tires, both in the OE and replacement market segments.
According to the latest figures from the Rubber Manufacturers Association (RMA), every second tire shipped to an assembly plant in the U.S. last year was H, V or Z speed rated and every third passenger tire shipped to the aftermarket was similarly speed rated.
In both cases, shipments of speed-rated tires last year jumped by double-digit percentages over 2013.
At OE, 2014 was the fifth straight year of double-digit growth of shipments of speed-rated tires to the car makers, the RMA data show. (See table, page 13.)
The percentage of speed-rated tires fitted at OE is now twice what it was in 2006, and preferred OE fitments have skewed noticeably toward larger and wider. The top 10 OE sizes last year included two 20-inch and four 17-inch fitments and only one 15-inch spec, according to the RMA data.
It should be noted that not all of the growth in speed-rated tires at OE is necessarily muscle- or sports-car related.
A fair amount of the growth derives from car makers' specifying speed-rated tires on more standard sedans and coupes that have been outfitted with engines capable of pushing those vehicles to higher speeds, or the car makers' engineers opting for performance tires for enhanced handling.
This trend, developing over the past several years, prompted Falken Tire Corp. to start advising consumers to be careful when choosing the speed rating on replacement tires.
High speed ratingswhich indicate how fast a tire can roll at specified sustained speeds safely carrying a loadno longer are limited to the performance category, said Rick Brennan, executive director of marketing at Falken.
When replacing tires, consumers need to ensure that they're not compromising safety by opting for a lower-speed rated tire.
Changing fuel-economy standards have been the prime reason more cars are coming equipped with higher speed-rated tires, Falken Tire said.
Today, it's the rule rather than the exception for manufacturers to equip traditional family vehicles with super-efficient small displacement engines, Mr. Brennan said.
With up to 200 horsepower, you're as likely to see a 4-cylinder sedan as an 8-cylinder sports car equipped with high speed-rated tires, such as a V-speed rating (up to 149 mph).
While it may seem like overkill for a basic transportation vehicle, he said, it's a trend that's here to stay, thanks to ongoing advancements in small engine technology.
For consumers preparing for a tire swap from winter to all-season or summer tires, Falken Tire is advising consumers to:
c Never downgrade a tire's speed rating;
c Don't rely on a tire's speed rating to tell how much grip or cornering ability a tire providesa speed rating does not necessarily correlate to cornering capability; and
c Never mix and match tires with different speed ratingsthis could not only reduce the speed at which a car can operate safely, it also could result in potentially serious vehicle handling problems, including unpredictable steering.
While the shift to speed-rated tires is happening more quickly at OE, it's worth noting that the aftermarket is embracing Z-rated tires at twice the pace that the car companies are.
Z-rated tires made up 21 percent of aftermarket speed-rated shipments last year vs. just 10 percent at OE, according to the RMA data.
Likewise, imports of passenger tires last year reflected the shift in the U.S. aftermarket, with imports of tires 16 inches and greater in rim diameter jumping nearly 20 percent. The biggest single increase was in the 17-inch categoryup 22.8 percent.
By contrast, shipments of tires up to 15 inches in rim diameter fell 4.2 percent collectively.
The average declared customs value of imported tires by rim size was: 16 inches$54.31; 17 inches$69.57; 18 inches and larger$89.89.
In each size, China was the No. 1 source of tires and easily the least expensive, priced about 35 percent below the average for each size.
At the top of the list wer tires in the 18-inch and larger category from Czech Republic, with a value of $162.47.
Securing OE fitments on high-profile performance and luxury cars is seen as a key component of many tire makers' image-building efforts, which was illustrated at some of the major car shows this year.
Pirelli Tyre S.p.A., for example, touted its growing presence in the premium OE sector at the recent Geneva International Motor Show, disclosing it had gained 213 homologations in the premium and prestige sectors in 2014, a 6-percent gain over 2013.
Of these 213, Pirelli said 118or 55 percentwere marked tires, or those with special sidewall markings to indicate they are tailor-made for a specific vehicle manufacturer.
Overall, Pirelli said it achieved 266 new homologations last year, boosting its total to 1,846 with vehicle makers worldwide. Included in the new homologations are several for the tire maker's products with Seal Inside puncture-sealing technology.
Among new OE fitments disclosed at the Geneva Motor show were: Lamborghini Aventador LP 750-4 Superveloce; Audi Q7 and Q3; Volvo XC90; and BMW X5M and X6Mall using either Pirelli's Scorpion Verde or Scorpion All Season or P Zero variants.
Likewise, Group Michelin promoted the selection of Michelin-brand tires on a half-dozen of the hottest cars at the North American International Auto Show in Detroit as reflective of its role as a preferred technology partner with many of the world's leading car makers.
Top of the list at the Detroit show this year is the Ford GTthe latest iteration of the iconic mid-engine two-seater sports car/racer the Ford Motor Co. originally launched in the mid-1960s as it chased victory at the 24 Hours of Le Mans endurance race.
The latest version is powered by a twin-turbocharged 3.5-liter, 600-plus hp EcoBoost V6 and will roll on Ford GT-specific 20-inch Michelin Pilot Sport Cup 2 tires.
Other cars outfitted with Michelins at the 2015 NAIAS included: 2016 BMW X5M and 2016 BMW X6M; 2016 Cadillac ATS-V and CTS-V; 2015 Corvette Z06; and 2016 Shelby GT350 and G350R Mustang. Other exclusive Michelin fitments available in North America include: BMW M3 and M4; Ferrari 458 Speciale; Mercedes Benz SLS AMG Couple Black Series; and Porsche 918 Spyder and 911 GT3R.
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