Tread Depths & Tyre Performance on wet & dry surfaces
All grooved motor sport tyres will have some tread flex. On dry surfaces tread flex reduces overall grip levels and therefore lap times. To optimise dry grip levels with grooved race tyres, tread flex needs to be minimised. The more groove area or "void" a tread pattern has, the greater the amount of tread flex there will be in dry conditions.
PROXES RA1 - This pattern has a tread depth of 6mm or >6mm when new and has enough groove area to be very effective as a "wet" with new tread depth or close to new tread depth. For optimum dry track performance, buffing will make a large difference in grip and endurance for the Proxes RA1 and is highly recommended. Buffing will also provide more even tread wear and a slower wear rate.
PROXES R888 - This pattern has 5mm of tread depth when new and minimal groove area on the tread shoulders for optimum dry track performance. Buffing the Proxes R888 will provide a small improvement for cornering grip on dry tracks.
PROXES RR1 - This tyre is designed for wet weather use only and will provide optimum aquaplaning resistance with new tread depths. Aquaplaning resistance reduces as tread wears. The tread compound of this tyre will over-heat very quickly where a dry line begins to appear.
Click here to view Technical Information article "Buffing or shaving tyres used for motor sport".
Tread Temperatures
As for most motor sport tyres, Toyo motor sport radials can be slippery when cold. Caution needs to be exercised until the tyres have had some time to warm-up. For the Proxes RA1 tread compound and the Proxes R888 & Proxes RS1 "GG" tread compound, grip levels will be low when the tread temperature is less than 55 degrees Celsius.
Optimum operating temperatures for the Proxes RA1 tread compound and the Proxes R888 & Proxes RS1 (slick) "GG" tread compound is between 75 and 95 degrees Celsius. Over 100 degrees Celsius, grip levels drop-off rapidly.
Rim widths and tyre performance
Toyo motor sport radials will provide optimum performance where the rim size allows the sidewall to have little or no protrusion from the rim flange.
Each Toyo motor sport radial product information page includes a link to download a PDF file that quotes dimensional information, including approved rim widths. Where possible, use of minimum rim widths should be avoided. For most sizes, optimum tyre performance will be provided with rim widths that are from the mid point to the maximum in the range of approved rim widths shown.
Tread Compounds
Proxes RA1: Available in one tread compound only for all sizes. NOTE: Late production Proxes RA1s will have a UTQG Treadwear Rating of 100. Older Production Proxes RA1s will have UTQG Treadwear Ratings of either 50 or 40, depending on the tyre size. The Proxes RA1 was re-tested, and due to changes with the UTQG testing procedures, Proxes RA1s will now have a UTQG Treadwear Rating of 100. There has been no change of tread compound for the Proxes RA1.
Proxes R888: All Proxes R888 tyres held in stock are "GG" tread compound. The "GG" is a versatile tread compound, suitable for a wide range of applications.
The Proxes R888 is available with the "GGG" tread compound in a small range of sizes from Toyo motor sport dealers by indent order only. No "GGG" tyres are kept in stock due to a short shelf life of this tread compound. The "GGG" tread compound is suitable for a narrow range of applications only, and has a much faster wear rate compared to the "GG" compound.
The tread compound of each Toyo Proxes R888 tyre is marked on the sidewall.
Proxes RS1: All Proxes RS1 tyres use the same "GG" compound as used on the Proxes R888.
Proxes RR1: All Proxes RR1 tyres use the "SG" tread compound. This is a very soft compound that is suitable for use in on wet tarmac only. The shelf life of the "SG" tread compound is very short.
Please contact your Toyo motor sport dealer for Toyo Technical Department for information regarding suitability of tread compounds for specific applications.
Street use
The Toyo Proxes RA1, Proxes R888 & Trampio R8881 are legal for use on public roads but recommended for competition or use on closed circuits. Grooved, street legal race tyres are designed for users who need to drive their vehicle to and from the circuit, and / or where the class regulations specify that street legal tyres must be used.
When compared to high performance or ultra-high performance tyres, when used on public roads, Toyo motor sport radials will:
1. have comparatively poor ride comfort. Toyo motor sport radials have a steel sidewall ply to minimise sidewall deflection for optimum cornering grip.
2. be susceptible to "tram-lining" / "tracking". The casing stiffness provided by the steel sidewall ply and wide belt packages used on Toyo motor sport radials make them susceptible to tram-lining caused by road irregularities common on public roads.
3. have faster tread wear. The tread compounds used on Toyo motor sport radials provide much higher grip levels compared to high performance or ultra-high performance tyres rather than long tread life.
4. be slippery when cold. Due to the tread compounds & construction types, grip levels will be low until the tyres have had some warming-up. This will be especially noticeable in cold and / or rainy conditions.
5. be susceptible to aquaplaning when used with low tread depths (3 -1.5mm) on wet roads, especially in heavy rain conditions. Users need to exercise caution in these conditions with careful monitoring of vehicle speed to avoid aquaplaning. The Proxes RA1 pattern is the exception. The Proxes RA1 has a void ratio that makes it resistant to aquaplaning, where tread depths are >4.5mm. For more information on wet road grip and aquaplaning, click here.
Using different tyre types and patterns on one vehicle
Mixing high performance street tyres and motor sport tyres on one vehicle: Some users try to address a lack of grip on an axle by fitting motor sport tyres to the axle that has a grip deficiency, and using high performance street tyres on the other axle. This practise is not recommended as it creates a grip imbalance. The fastest lap times will be achieved by addressing the oversteer or understeer problem by suspension and chassis tuning. The exception to this is drifting, where it is common to use motor sport tyres on the front axle and high performance street tyres on the rear axle to promote progressive oversteer.
Mixing different brands and / or patterns of motor sport tyres on one vehicle: This should also be avoided where possible to avoid handling imbalance. Different casing constructions and tread compounds provide different grip levels, warm-up times and handling characteristics. Having tyres of the same tread compound & construction type on both axles will promote balanced handling.
CAMS Approval
Proxes RA1: Production Cars. Refer to Schedule E in the CAMS Manual of Motor Sport.
Historic Touring and Historic Production Sports Cars. Refer to the Approved Tyre List for Groups Na, Nb, Nc, Sa, Sb & Sc in the CAMS Manual of Motor Sport.
Proxes R888: Production Cars. Approved in 2005. Click here to download CAMS Bulletin (PDF File).
Historic Touring and Historic Production Sports Cars, Groups N and S. Approved in January, 2006. Refer to the CAMS Manual of Motor Sport for class tyre size regulations. Click here to download CAMS Bulletin (PDF File).
Parallel Import TOYO Motor Sport Tyres
Important information Bulletin for TOYO motor sport tyre dealers and users regarding parallel import Proxes R888 motor sport tyres.