Wheels & Tires 101

Installs & Reviews PAS Staff | Photography by Dave Pankew

Tires – they are the most important part of your car. Not only are they responsible for keeping you stuck to the asphalt, they are the last piece of your power puzzle – the better they are, the quicker and more responsive to your throttle.

Most of you also know that different tires are made for different applications – whether you take your car to the track, or cruise around and show it. There are a lot of tires out there that claim to pull double-duty on the street and at the track and that’s not always a bad thing – especially if it’s a rare occurrence to let your car go wide-open. But a soft street tire with excellent grip will wear out pretty quick on the track and likewise, a hard DOT tire that is durable on-track could spell disaster on wet street conditions.

The guys here at PASMAG run different tires for each application, so we put together this guide to help you choose the best for yours. To give some insight on some of the newest products, our editorial team was sent out to test some of the best of what the industry had to offer, travelling from New Orleans to Utah to burn rubber on some of the coolest tracks around. We also included some of the hottest performance and show-worthy wheel options to match your ride and your rubber.

Take a look, hopefully you’ll find something that’s just right for you. And if you’re unsure of what all the numbers and letters mean, the info below should help put you in the right direction!

Choosing the tire that’s right for you

When choosing the right tire, there are more factors to consider than just size. You will have to examine the Uniform Tire Quality Grading or UTQG. The UTQG gives an insight as to how well the tire will grip, how it performs under high temperatures and how long the tire should last.

The UTQG is made up of three categories:

1) Tread wear – This is the number designation given to the tire to determine the wear rate of the tire. The higher the number the better. A rating of 300 should last approximately 30,000 miles (in ideal conditions) and likewise a 400-rated tire should last twice as long as a 200 rated tire. But remember, this does not determine performance – many high-performance tires have lower ratings because they provide excellent grip, but wear fast.
2) Traction rating – Rated from high to low, tires either receive an AA, A, B or C rating. The rating depends on the ability of the tire to stop on wet pavement. Generally you want this to be high, but again it depends on your use (ie. if it’s going to be a street or track tire).
3) Temperature rating – Again rated from high to low, tires are given an A, B or C designation for their ability to dissipate heat and resist heat degradation. The temperature rating is based on a 30 minute test at high-temperatures to ensure against sudden tire failure or a drop in performance.

Letters and numbers: what’s it all mean?

265/35 R18:

265mm (10.4-inches) wide
35-profile is 35-percent of the width (sidewall height = 92.75mm or 3.6-inches)
R is for radial technology
18 is for the diameter of the wheel (in inches)

Finally there is the load and speed rating found on every tire. From the factory, these values are expressed as a number and letter after the tire size. Sometimes the speed rating can also be incorporated into the tire size (ie. 265/35 YR18).

A 93Y on the load index means the tire can handle up to 1433 lb. of load. The Y indicates the top speed rating. See the chart below for the complete measurements.

Speed Rating

Q   =   99 MPH, 160 km/h
R   =   106 MPH, 170 km/h
S   =   112 MPH, 180 km/h
T   =   118 MPH, 190 km/h
U   =   124 MPH, 200 km/h
H   =   130 MPH, 210 km/h
V   =   149 MPH, 240 km/h
Z   =   149 MPH, 240 km/h
W   =   168 MPH, 270 km/h
Y   =   186 MPH, 300 km/h

Load Rating

Load Index Pounds Kilograms

71   761   345       91   1356   615
72   783   355       92   1389   630
73   805   365       93   1433   650
74   827   375       94   1477   670
75   853   387       95   1521   690
76   882   400       96   1565   710
77   908   412       97   1609   730
78   937   425       98   1653   750
79   963   437       99   1709   775
80   992   450       100   1764   800
81   1019   462       101   1819   825
82   1047   475       102   1874   850
83   1074   487       103   1929   875
84   1102   500       104   1984   900
85   1135   515       105   2039   925
86   1168   530       106   2094   950
87   1201   545       107   2149   975
88   1235   560       108   2205   1000
89   1279   580       109   2271   1030
90   1323   600       110   2337   1060

Lastly, with the ‘hella flush’ craze, everyone is trying to go wider with lower offsets and stretched tires. While we admit it can look sick when done right, these fitments are no where near recommended widths, camber or offsets. In some States and Provinces it is illegal to have any part of the wheel extending beyond the bodywork. Obviously you want to do it right before dropping down a ton of money, so make sure you do your research!

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