Whether you stalk the local street-racer hangouts at night in search of glory and loot, or you're out to show off your high-powered exotic at the amateur autocross, you should always make sure you have the right tires. And, more importantly, you should know your enemies' tires. Few take the time during those tense battle-preparation moments to kneel down and check out the raised glyphs on their competitors' black sidewalls. Such an oversight could determine which side of victory's and defeat's very fine line you end up on. Whether you're wheel spinning at wide-open throttle or plowing off the course, nothing sucks like losing to the little guy--the little guy with traction that is.
If victory, and thus grip, mean everything, you might consider a set of D.O.T.-approved R-compounds tires: an amalgamation that's neither street tire nor race tire. R-compound tires can guarantee a "cheating" victory, unless the other guy has caught on, too. By definition, the tires that fall within this guide's parameters are commercially available tires that are D.O.T. certified and are considered driveable on the street. Wannabe slicks that barely meet D.O.T. requirements were left out since even the manufacturers do not recommend using them on the street. R-compound tires still use radial construction technology, but feature strengthened sidewalls and super sticky rubber. Maximum tread depth starts at 8/32 in. and can be ordered shaved down to 3/32 in. But worry not, those grooves won't stay there long.
european car has opted to classify everything that falls between the minimal D.O.T. certification and the top of the line Max-grip tire as an R-compound tire. Granted, that leaves a lot of tires in the mix, including drag and autocross radials, which have very different sidewall constructions. The only good way to identify where an R-compound tire fits in between racing slicks and street radials is by looking at the tread and water channel design, and by reading the UTQG rating. UTQG is the industry standard for rating a tire's performance. The number represents the wear rating, followed by a letter traction rating and then a letter temperature rating. The lower the number, the faster the tire will wear out. For reference, the tires on a Chevy Impala have a UTQG wear rating of 560. Some race-governing bodies consider anything that has a UTQG wear rating of less than 140 not to be a street tire. Incidentally, all of the following tires have a wear rating of less than 100, but can still be driven on the street. You get the picture.
These tires are for die-hard at-speed junkies, who, not incidentally, also have a lot of disposable cash. Warning: Don't make the mistake of taking these tires to your local professional autocross or drag competition. Though these R- compound tires are fast and sticky, you'll still have your bottoms handed to you by the guys running non-radial or cheater slick tires in competition. Be sure to check the regulations for your class--to help you, we've compiled a list and posted it on www.europeancarweb.com. Now go out and establish dominance in your realm. Just be ready to pay for another set--real soon.
BFGoodrich g-Force T/A Drag Radial
BFGoodrich was first to introduce a street-legal drag radial for the enthusiast with uncompromising needs for straight-line traction. The twin full-width steel belts and stiffened crown are designed to resist tread distortion under hard acceleration. The versatile street compound offers realistic wear for street applications while providing great launch traction over a wide range of temperatures.
The shallow-tread groves minimize the amount of movement of the large tread blocks and resist chunking of the tire rubber. The drag radial is specially designed to have sufficient sidewall rotational compliance for added grip on drag launches. The current g-Force T/A Drag Radial line has three tread patterns to cover the range of sizes available. The conventional tread pattern, originally the comp T/A drag radial, is now merged with the g-Force name for applications on rear-drive high-horsepower applications. Two other tread patterns from the newer g-Force line released 3 years ago are intended for sport compact applications for front-, rear- or all-wheel-drive configurations. Personal experience has shown that it is far easier to slip a clutch than these tires on a hard drag launch. Available sizes range from 14- to 18-in. wheel diameters with a UTQG tread wear rating of 00/B/C, making it very clear that the tire is not intended for long mileage.
Dunlop SP Super Sport Race
Dunlop's SP Super Sport Race is an extreme-high-performance sport radial designed for supercar owners and autocross enthusiasts who want a non-competition, D.O.T.-legal tire that provides the maximum in dry grip. This tire combines technology developed for the Dunlop DTM Race Series tire and the street characteristics of the SP Sport 9000 Max-Grip tire. The SP Super Sport Race is available in eight sizes from 17- and 18 in. with a 60/A/A UTQG.
Hankook Ventus Z211
Hankook's entry into the competitively priced R-compound tire market is the Ventus Z211. This tire is designed as an autocross tire with emphasis on both wet and dry traction for use on street and track. The asymmetric design features a large continuous tread block on the outer shoulder and large non-continuous water sipes on the shoulder. Two circumferential rain-groove elements help straight-line traction for street use. The Ventus Z211 205/50ZR15 R-compound is the official spec tire for the SCCA's newest series--the Mazdaspeed Miata Cup Championship presented by Hankook Tire. The Z211 comes in sizes 13- to 17 in. with a UTQG wear rating of 50/AA/A.
Kumho Victoracer V700
Kumho's long-running Victoracer V700 has become one of the long-standing favorites of competitive autocross and circuit racers. The directional and asymmetric design of the tire encapsulates all the key characteristics that the tire was designed for: grip, wet traction and control, and streetability. Victoracers are well liked for their versatility and also their tolerance for driver skill levels. The V700 was designed to have the grip and sidewall stiffness necessary for competitive levels and still be temperature tolerant enough to accommodate different driving styles and have nominal grip. Sizes available from 13- to 17-in. wheel diameters with a UTQG tread wear rating of 50/AA/A.
Kumho Ecsta V70A
The Ecsta V70A is designed for more entry-level autocrossers who do not require the asymmetric design, allowing the tires to be remounted "inside-out" for life extension. The tread design is distinctly different from the Victoracer and is more applicable for autocrossing due to its lower speed rating on some sizes. This tire incorporates much of the technology of the Victoracer with reduced complexity and cost to the buyer. The V70A comes in sizes 13- to 18 in. with a UTQG tread wear rating of 50/AA/A.
Michelin Pilot Sport Cup
The Pilot Sport Cup is the extreme of the Pilot Sport Line, originally designed for Porsche club racing--where affluent drivers are more willing to sacrifice longevity for additional grip. The Cup provides performance that far exceeds what a max grip or UHP tire is capable of while shedding other non-track-essential features. The sidewall design is similar to the other tires in the Pilot Sport Series, however, the tread pattern is asymmetrical and drastically different. The tread uses a dual-zone compound that has a soft dry compound for the outer shoulder and wet compound on the inside with the directional sipes. The outer shoulder features a continuous contact patch broken only by small voids to hold water. Internally, the Pilot Sport Cup features two, full-width steel belts reinforced with Michelin's Banded At Zero (BAZ) technology to stiffen the tread area to help prevent the contact area from distorting during aggressive acceleration, cornering and braking. The Cup comes in sizes 15- to 18 in. and has a 80/AA/A UTQG wear rating.
Nitto NT 555R Extreme
From the popularity of its NT 555 performance tire designed for the aftermarket, Nitto introduced the NT 555R Extreme. It's a D.O.T.-legal streetable drag radial, featuring the same tread pattern but with a softer compound and reduced tread depth. It still maintains a tread life of 15,000 miles of normal street driving, according to Nitto. Internally, the NT 555R features two full, wide steel belts and two nylon tread cap plies similar to the street NT 555. Since the NT 555R is primarily meant for competition drag racing, sizes range from 14- to 18 in. with a UTQG tread wear rating of 100/A/A.
Nitto NT 555RII Extreme R
In similar fashion to the NT 555R, Nitto engineers specifically designed an R-compound tire based on the NT 555 tread pattern for autocross competition. This D.O.T.-legal tire also uses a softer compound and reduced tread depth specifically engineered for the long-duration, high-temperature rigors of autocross racing. Internally, the NT 555RII has two, full wide steel belts and two nylon tread cap plies, and it is designed and reinforced to increase sidewall rigidity for competition. Sizes range from 17- and 18 in. with a UTQG tread wear rating of 100/A/A.
Pirelli PZero Corsa
Pirelli's new generation of R-compound tires has a radically different tread pattern when compared to the standard PZero. The Asymmetric and directional tread design is molded in the standard 6/32-in. tread depth or can be ordered shaved between 3/32- to 4/32-in. tread depth. The Corsa has a highly flexible steel-belted interior construction reinforced by spirally wound nylon to enhance performance and reduce weight. Applications are available in 17- and 18-in. wheel diameters with a 60/AA/A UTQG tread wear rating.
Toyo RA-1
Known for its use as the official spec tire of the Speed World Challenge Series, the RA-1 has been a favored choice for weekend racers. The RA-1 is designed for touring and autocross racing and comes with a directional 8/32-in.-deep tread pattern, which can be shaved down to 4/32 in. A two-ply rayon casing construction is used along with steel-wire reinforced sidewalls to improve handling characteristics and also increase the thermal stability and heat resistance. A large range of sizes is available between 13- and 18-in.wheel diameters with a UTQG tread wear rating of 40/A/A.
Yokohama A032R H/S
Yokohama's A032R is an entry-level autocross, track school tire that is well suited for street driving and high-performance applications. The Aqua Tusk design features huge tread blocks that are broken by directional grooves and sipes that extend all the way to the tire shoulders for good water evacuation. The H/S rating refers to the hard (H) or soft (S) compound that the A032R is available in. Harder compounds are generally recommended for higher powered, heavier vehicles or where endurance for multiple track sessions is desired. The soft compound is better for lighter, lower-powered vehicles that can take advantage of softer tires and not wear through them with excessive tire spin. Yokohama offers the A032R in the standard 6/32-in. tread depth or as shaved tires for exclusive track use. It is available in sizes 13- to 17-in. sizes with a 60/A/A UTQG tread wear rating.
Yokohama A048
The A048 is a circuit-racing tire originally designed for circuit applications on Porsche 911 cars. It has even less emphasis on street use with respect to water evacuation than the A032R. The race-ready compound is molded as one continuous tread block interspersed with rain grooves that decrease in depth near the shoulders and do not extend all the way to the tire sidewalls. This basically allows water to be held in the voids, and pushed forward or backwards, but not out the sides to compromise cornering traction. The A048 comes in three sizes: 225/40R18 88Y, 256/35R18 93Y, and 285/30R18 93Y with a 60/A/A UTQG tread-wear rating.