Is there a list of legal tire brands and sizes that we can use for USCA ETC. events

[Cdog]

We’re discussing rim size and tire fitment with our rim manufacture for my 69 Camaro. The rear is tubbed so we will most likely run a 18X12 with a 335 rear. Matching the front is a more complicated issue. I have an Art Morrison C6 subframe so a 18X10 275 front is my baseline. However were going to build some wide body front fenders with the intent to get an additional 1 7/8 or 1.875 room under the front end. I’m not sure if I’m seeing all sizes/Tire manufactures that are available but a 305-315 on a 18X11 inch rim seems doable.

Has anyone done this combo yet?
Is there a specific tire that performs best for events?
Right now we’re looking at a 18X11 front rim to run a 305 or wider front tire up front? Any input?

Thanks in advance!

[Cdog]

An example.

Stock Tire Size
275/35R18 IMPERIAL METRIC
Section Width: 10.83 in 275.00 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 9 - 11 in
Overall Diameter: 25.58 in 649.70 mm
Sidewall Height: 3.79 in 96.25 mm
Radius: 12.79 in 324.85 mm
Circumference: 80.36 in 2,041.09 mm
Revs per Mile: 813.18/mi
Actual Speed: 62.14 mph 100.00 kph
Speed Variance: -
Diameter Variance:


OR

315/30R18 IMPERIAL METRIC
Section Width: 12.40 in 315.00 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 11 - 12 in
Overall Diameter: 25.44 in 646.20 mm
Sidewall Height: 3.72 in 94.50 mm
Radius: 12.72 in 323.10 mm
Circumference: 79.93 in 2,030.10 mm
Revs per Mile: 817.58/mi
Actual Speed: 61.80 mph 99.46 kph
Speed Variance: 0.54% too fast.
Diameter Variance: -0.54%


The 315/18 is 1.57 wider than the 275/18. This appears to put me within margin.

Paired with for rear


335/30R18 IMPERIAL METRIC
Section Width: 13.19 in 335.00 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 12 - 13 in
Overall Diameter: 25.91 in 658.20 mm
Sidewall Height: 3.96 in 100.50 mm
Radius: 12.96 in 329.10 mm
Circumference: 81.41 in 2,067.80 mm
Revs per Mile: 802.67/mi
Actual Speed: 62.14 mph 100.00 kph
Speed Variance:




Matching Tire options are:

FrontTire Models Available by Size:
Nitto NT01

Toyo Proxes R888

Pirelli P-Zero Rosso

Michelin Pilot Sport PS2


RearTire Models Available by Size:
Nitto NT555R

Toyo Proxes R888

Michelin Pilot Sport PS2

Pirelli P-Zero Rosso

[SSLance]

I believe the only tire restriction is they have to be at least 200TW.

[Paul Huryk]

I would try to have the tires as close to the same size on the car - 315/335 is preferable to a 275/335 combo.

315-30-18 is a very popular size in many different patterns, so I would seriously consider that in the front on a 11" (or 11.5") wide wheel.

As SSLance mentioned, most events are based in treadwear rating, not spec tires like some organized road race series use.

[Cdog]

I would try to have the tires as close to the same size on the car - 315/335 is preferable to a 275/335 combo.

315-30-18 is a very popular size in many different patterns, so I would seriously consider that in the front on a 11" (or 11.5") wide wheel.

As SSLance mentioned, most events are based in treadwear rating, not spec tires like some organized road race series use.


This is why I’m asking. I have a good friend at Toyo but the Proxes are 180 TW. Sucks because they have a wide rage of tire selection for 18’s on the large side.


Is there a list of 200 TW

[72BBSwinger]

BFG Rival has both of your sizes. Other than that, its Michelin PS2. Falken has the fronts only. I wish they would allow Toyos or Hoosiers. Or at the events make everyone run the same size either 275's or 295's squared. I think if there is a tire rule at all, it should be max size not TW.