Magazines:  Real Estate Shopping: Adult Costumes  |  Kids Costumes  |  Car Books  |  Guitars |  Electronics
This Issue Archived Articles Blog About Us Contact Us
SEARCH


Stick Like Gum '06

Our latest roundup of street-legal semi-slick tyres

By Michael Knowling

Click on pics to view larger images

At a glance...

  • Semi-slick tyres on the market
  • All street legal
  • Specs and prices
Email a friend     Print article
 

In 2000 and 2003 we presented you with buyers' guides to road legal semi-slick tyres (see http://autospeed.drive.com.au/cms/A_0593/article.html and http://autospeed.drive.com.au/cms/A_1883/article.html). Well, there have been quite a few changes in this segment and it’s time to bring you up to speed with what’s on the market.

But, first, why would anyone want to buy such a barely legal set of tyres?

Semi-slick tyres employ a softer rubber compound than normal high-performance tyres and the tread pattern has fewer grooves to further improve dry road grip. These tyres are also resistant to high temperature operation (such as when driving on a racetrack) and have stiff sidewall construction to maximise chassis feel and response. But there are a couple of factors to be aware of. The soft rubber compound gives poor wear characteristics (you’ll typically get less than 15,000km from a set of tyres) and the lack of tread means wet weather grip is generally poorer than conventional tyres.

In addition, you should double-check legality and make sure that your vehicle insurer is informed of their fitment. Most insurers will let you go ahead with semi-slick tyres so long as they have official street-legal approval – this is identified by the letters DOT (an abbreviation for the Department of Transport) or E (the European legal compliance symbol). Be on the lookout for tyres marked ‘Not for Highway Use’ or ‘For Racing Use Only’.

Comparing Tyres

Some tyres carry Uniform Tyre Quality Grade (UTQG) data which is a valuable tool when comparing to other brands.

Here’s how it works.

Let’s use the example of a tyre having a UTQG label of 60-A-C.

The number 60 identifies the tyre that has a tread wear index of 60 (the lower the number, the softer the tyre). The next two letters identify the traction index and temperature resistance index, respectively. A school type grading system is used – an A, B or C grades are awarded.

DOT Legal Semi-Slicks

Note that the tyres listed here are available in Australia and/or the US – it some instances, other countries may have the same tyre available under a different name. For comparative purposes, the prices quoted are for a 225/50 16 size (where possible).

BF Goodrich

Since our previous Stick Like Gum feature, there has been no change in the BF Goodrich range of street legal semi-slicks.

Click for larger image

"Hero-making traction and control come to the strip" is the catchphrase for the BF Goodrich G-Force T/A Drag Radial. With a primary focus on quarter mile performance, the G-Force T/A Drag Radial is fully street legal and features two full-width steel belts and 5.5/32 of an inch tread depth giving maximum straight-line traction and predictability. It is also reputedly "comfortable to drive to and from the strip."

The new Drag Radial T/A is available in selected sizes between 14 and 18 inch.

Speed Rating: Not available.

UTQG Rating: 0(!)-B-C.

Approximate Price: A 225/50 16 size is not available but a 255/50 16 costs around US$200.

Dunlop

In late 2003, Dunlop released a tarmac rally tyre which carries road legal identification. The Dunlop Motorsport Direzza 02G is designed by Dunlop race engineers and complements the existing Formula R range.

Click for larger image

The Direzza 02G uses a reduced tread depth, high stability pattern and race tyre construction and tread compound. This product has so far proven successful in various Targa rallies. It is available in sizes from 165/60 13 to 265/35 18.

Click for larger image

Another relatively new addition is the Dunlop SP Supersport. The Supersport has a greater number of tread cuts making it more suitable for street use and it is available in a selection of large diameter sizes – 17 to 19 inch.

Old faithfuls, such as D98J (which is now effectively superseded but remains available in limited sizes), the D01/2J, Formula R SV98 and a wet weather version - the D93J - are also available.

Click for larger image

Formula Rs have won the Bathurst 12 Hour, the Eastern Creek 12 Hour, Targa Tasmania, three Peaks Rallies, Dutton's GP Rallies, Indy GP Rallies, the Panama Alaska Rally and more. Formula Rs are available in sizes from 165/70 10 to 255/40 17, while the Formula R SV98 comes from 195/55 15 to 265/35 18.

Speed Rating/UTQG Rating: Not available.

Approximate Price: Around AUD$400 for a 225/50 16 depending on model and availability.

Nitto

Click for larger image

A newcomer to the market is the DOT approved Nitto NT555R Extreme Drag Radial tyre. This tyre is primary designed for drag use but is quite streetable and can go more than 20,000km in normal use. NT555Rs are manufactured with a tread depth of 6/32 of an inch and use a specially formulated racing compound to provide maximum traction.

Nitto NT555Rs are available in diameters 14 to 18 inch and widths from 205mm to 335mm.

Speed Rating: All V rated.

UTQG Rating: 300-A-A

Approximate Price: A 225/50 16 size is not available but a 245/50 16 costs around AUD$300.

Hoosier

Click for larger image

Only just DOT approved is the recently released Hoosier's Radial A3S05/R3S05. These tyres use dual grooves around their perimeter, are quick to warm up and are resistant to high temperature operation. They’re great for autocross, time trials and hill climbs but, given their near tread-less appearance, we’d suggest thoroughly checking out their legality before purchasing...

Combined, the A3S05 and R3S05 are available in sizes from 185/60 13 to a massive 335/30 18.

Speed Rating: All Z rated.

UTQG Rating: 40-C-A

Approximate Price: US$200

Kumho

VictoRacer V700 is the premium performance tyre from the Kumho range. This product is fully moulded, features a highly developed tread compound and an asymmetric pattern to provide maximum cornering power. Steering response is also outstanding thanks to the very stiff sidewalls. A tread depth of between 5 to 6/32 of an inch indicates this is extreme performance tyre.

The latest DOT approved competition tyre in the Kumho range is the Ecsta V70A (aka V700).

Click for larger image

The Ecsta V70A uses Kumho's specially formulated high grip silica competition tread compound combined with a directional design that features wide tread ribs in the shoulders and intermediate tread blocks to maximise dry cornering grip. Its directional tread design also helps provide wet traction when run at full tread depth. The Ecsta V70A is moulded with 6/32 inch of tread depth in its two major circumferential grooves. The V70A is also lighter than the Victoracer and, unlike the Victoracer, you can remount the Ecsta ‘inside-out’ to extend its serviceable life.

VictoRacers are available from 205/60 13s up to 315/35 17s while the Ecstas are available from 175/60 13 to 335/30 18.

Speed Rating: The VictoRacers are V-rated in 13-14 inch sizes and Z-rated for 15-17 inchers. The 13 to 15 inch Ecstas carry an H, V or Z rating while larger diameter versions (16 to 18 inch) are all Z rated.

UTQG Rating: 50-A-A.

Approximate Price: VictoRacer US$160. A 225/50 16 size is not available in the Ecsta but a 225/50 15 costs around US$150.

Pirelli

Click for larger image

The P Zero C is Pirelli's most purposeful tyre that is legal for road use - although it is mainly intended for circuit use. It features "excellent road holding near the limit, constant performances under very high speeds and a high resistance to the physical/mechanical stresses arising from circuit use". With a ZR (240 km/h) rating, the P Zero C also has an asymmetric tread design possessing extra large outer blocks to allow maximum road holding and stability in bends.

Click for larger image

In addition, there’s now the Pirelli P Zero Corsa DOT legal competition tyre. Designed for driver training schools and special event lap days, the P Zero Corsa is moulded with 6/32 inch of tread depth in its grooves and is available unshaved for use on damp tracks. It can alternatively be shaved to between 3/32 and 4/32 of an inch tread depth for use on dry tracks.

P Zero Cs are available in sizes starting from 195/50 15 up to 245/45 16 while the P Zero Corsas are available from 205/50 17 to 315/30 18.

Speed Rating: We believe they are all ZR rated.

UTQG Rating: Not available.

Approximate Price: Around US$210 for a Pirelli P Zero C. A 225/50 16 size is not available in the P Zero Cosa DOT competition tyre range but a 225/45 17 costs around US$225.

Yokohama

Click for larger image

Yokohama has recently released an all-new DOT legal semi-slick tyre – the Advan A048. This tyre is ideally suited for targa type road events, club sprints, lap dash events, circuit racing and club level events such as supersprints, motorkanas and hill climbs. It is also the official control tyre in a range of Australian motorsport categories including the V8 BRutes and the Production Car Championship. Tread depth is 6/32 of an inch but they should be shaved for maximum grip on a dry circuit.

Click for larger image

The older generation Yokohama A032R is also available at most performance retails. The A032R (successor to the A008 series) is a proven top performer which offers a good combination of dry and wet bitumen grip, progressive breakaway and clearly visible tread - which reduces the likelihood of being pulled over by the police for ‘bald’ tyres...

The A048 is available in sizes from 205/50 15 to 315/30 18 while the A032R is available from 175/60 13 to 255/40 17.

Speed Rating: In the A048s, there’s a range of H, V, W and Y speed ratings depending on size. In the A032R range, the speed rating for 60 series tyres is H, 50 series are V and 40/45 series are Z rated.

UTQG Rating: 60-A-A

Approximate Price: Around US$191 for an Advan A048. A 225/50 16 size is not available in the A032R range but a 235/40 17 costs US$146.

Bridgestone

Click for larger image

The Potenza RE540S and RE55S are Bridgestone's offerings. The older RE540S (which is gradually being phased out) is a directional tyre with a standard tread depth of 5.2mm and an extra-stiffened sidewall. This sidewall is rumoured to be amongst the firmest in this category of tyre and it has a reputation for excellent balance between dry and wet weather grip. The latest release RE55S (pictured) is very similar but is intended more towards dry performance and comes in larger sizes.

The RE540S comes in a choice of sizes from 165/65 13 to the 205/65 15. The RE55S comes from 185/55 14 to 285/30 18.

Speed Rating: In the RE540S and RE55S range, the 60 series tyres are H rated, the 50-55 series are V rated and the 35-45 series are Z rated.

UTQG Rating: Not available.

Approximate Price: Around AUD$300.

Falken

Click for larger image

The Falken Azenis RT615 is this company's most appropriate road legal tyre. Although not as soft as some of the other tyres listed here, the RT615 is suitable for competition use and should deliver good grip thanks to its large tread blocks. Expect tyre life slightly better than the other tyres mentioned here.

The Azenis RT615 is available most common sizes from 175/60 14 up to 315/30 18.

Speed Rating: H or W depending on size.

UTQG Rating: 200-A-A.

Approximate Price: US$120

Toyo

Toyo's most popular DOT approved competition radial is the Proxes RA-1.

Click for larger image

Designed for "touring racing" and carrying CAMS approval, it uses steel wire reinforced sidewalls, an aggressive directional tread pattern with a 8/32 inch (6.35mm) depth for exceptional wet weather traction. It can also be shaved to improve dry weather lap times. Internally, the RA-1 features two wide steel belts, jointless edge and cap construction as well as a special tread compound to optimise adhesion and durability. In this segment, the RA-1 is also quite long lasting.

Click for larger image

In addition, you can now find the Toyo Trampio R1-R which is a unique hybrid ultra high-performance/race tyre designed for club motor sport competitors that regularly use their vehicles on public roads. Due to its aggressive tread pattern and tread depth, the Trampio R1-R is particularly effective for hill climbs and lap dash events on wet or dry tarmac. The original tread depth is up to 7mm but Toyo recommend shaving it to 2 – 3.5mm for maximum dry performance.

Click for larger image

Another new addition is the Toyo Proxes R888. The R888 has a low-void ratio for minimised tread squirm on dry tracks while the new groove design optimises water drainage from the contact patch. Round tread shoulders are also employed for progressive turn-in. This tyre provides competitiveperformance for a wide range of motorsport disciplines from hill climbs to endurance racing.

The Proxes RA-1 is available in a reasonable range of sizes from 185/60 13 to 335/30 18. The Trampio R1-R is available in only 16 and 17 diameters. Proxes R888s are available from 185/60 13 to 295/30 18.

Speed Rating: The smaller RA-1s up to 225/50 14 are V rated, while the larger sizes are Z rated. The R1-Rs are V rated while the majority of Proxes R888 are Z rated

UTQG Rating: The RA-1 is listed at 40-A-A but we are unable to find UTQG data on the Trampio R1-R and Proxes R888.

Approximate Price: AUD$310

Contacts:
Kevin Kenny Tyres (BF Goodrich)  +61 8 8232 5622 
Stuckey Tyre Service (Dunlop)   +61 3 9386 5331
      http://www.stuckey.com.au
Kym Davis Tyres (Hoosier, Bridgestone)  +61 8 8332 0800
Tyrepower (Falken, Toyo)   +61 8 8370 2195
Tire Rack online (Hoosier, BF Goodrich, Yokohama, Kumho)
http://www.tirerack.com
Toyo Tyres Australia    www.toyo.com.au
Trackside Tyres (Bridgestone, Falken, Hoosier, Toyo)
      +61 3 9761 5557
      http://www.tracksidetyres.com.au
VPW Australia (Nitto)    +61 3 8405 9280
http://www.vpw.com.au/

Did you enjoy this article?

Please consider supporting AutoSpeed with a small contribution. More Info...


Share this Article: 

More of our most popular articles.
Exploring some potential ultra light-weight vehicle building materials

Technical Features - 11 August, 2009

Cardboard Cars?

Stormwater and council inspection

DIY Tech Features - 20 March, 2012

A New Home Workshop, Part 6

Peak boost in one-third of a second!

Technical Features - 5 October, 2010

Is This Your Electric Supercharger?

A new low cost data logger - and how to use it on cars

DIY Tech Features - 7 July, 2009

Five Channel USB Data Logger, Part 2

Got an old cordless drill around the place? Here are the parts you can salvage from it!

DIY Tech Features - 8 May, 2008

A Heap of Parts for Nothing!

Unique and cheap modification to keep the car longer in lean cruise

DIY Tech Features - 7 April, 2008

Giving the Insight a Good Driver

The key to understanding lots of car-related things!

Technical Features - 20 August, 2013

Making sense of vibrations

DIY and commercially available vortex generators

Special Features - 10 October, 2006

Blowing the Vortex, Part 3

Turning the voltage switch into a standalone temperature or light switch

DIY Tech Features - 29 July, 2008

The eLabtronics Voltage Switch, Part 2

...but it never turned a wheel in anger

Special Features - 8 April, 2014

The fastest Mercedes of them all?

Copyright © 1996-2018 Web Publications Pty Limited. All Rights ReservedRSS|Privacy policy|Advertise
Consulting Services: Magento Experts|Technologies : Magento Extensions|ReadytoShip