STEP 3: SELECT YOUR TIRE
“What tires fit your category and size?”
Now that you have determined what your tire is going to be used for and the respective tire category, and with the newfound knowledge of how to look at tires by their true size, it’s time to select a tire. But with all of the different stats and criteria out there, what factors make a tire good?
Feel free to read the definitions below but I’ll save you some time with this sentence:
Due to the subjective or interpretive nature of these tests; other than speed ratings (which may not apply to most people) all of the other tire performance criteria is for the most part USELESS.
- You can read Tire Rack’s Load Index Definition if you want, but it’s basically the load carrying capacity of the tire, which usually isn’t important unless you’re making hundreds of pounds of downforce, have a heavy car, and are driving on an oval.
- Click the link above for more detail, but I mainly focus on tires with W (168mph), “99Y” (186mph), and “(99Y)” (Parentheses = 186mph+) based on the application. If you never go this fast (which you can’t do legally unless you’re on a racetrack, and even so, it’s rare to go this fast on track), then this probably does not matter.
Uniform Tire Quality Grade (UTQG)
- An arbitrary number originally developed to help consumers with a numerical value that represents the treadwear, traction, and temperature capabilities of the tire. Since the Department Of Transportation (DOT) does not test the tires and it’s up to the tire manufacturer to come up with the value, tire manufacturers set these numbers based on how they perceive the customer will understand how the tire will perform, or to meet a random number/standard that a racing series might restrict, to have a softer faster tire as an advantage. Because of all of this, UTQG is USELESS.
- A test based on a 7,200-mile test loop with routine tire pressure and rotation adjustments during it. A 100 rating should = the tread lasting the 7,200 miles, 200 rating = 2X that distance and so on. Since a lot is left open for interpretation and the only decently comparable data is from one tire to another within the same brand, this is also somewhat useless.
- This is another useless test since it measures the deceleration g-forces of a locked tire across a WET road at 40mph. Other than seeing which tire will stop you the shortest distance with the tires locked; this is not relevant to cars with ABS or the braking ability of the tire under normal rack uses.
Temperature (Resistance) Grades:
- Indicates the amount of heat generated by what appears to be an under-inflated tire at 85mph. Since this is also outside the scope of a properly maintained tire, I find it useless.
As tire technology gets better with each new design, often driven by what is learned in motorsports, tires are performing better in the dry and wet, are lasting longer, and are quieter than their predecessors. Keep in mind those manufacturers who are winning in multi-tire racing series tend to offer the best products to their customers as well.
These advancements make it difficult to properly classify a tire or draw conclusions that tire A lasts longer than Tire B because it’s Treadwear Rating is higher, or it will have more grip and wear out quicker because its UTQG is lower. Remember, these numbers are useless?
So back to the decision of selecting the best tire; when looking at TireRack’s subcategories
(“Ultra High Performance”, “High Performance”, “Performance”…) I usually look in the highest category. Price is usually a major factor in selecting a tire but since tires should be viewed as an INVESTMENT in terms of both performance and safety of your car, I rarely look below the second tier of subcategories.
TireRack’s rating table is going to be one of the best sources out there. Using a scale of 1-10, each tire is rated in terms of dry grip, steering response, wet grip, hydroplane resistance, road noise, longevity, etc… by consumer survey ratings which can be the average from hundreds of people. Having tracked many tires, I personally feel these figures are fairly accurate when comparing across brands and have the most credibility, especially compared to the useless UTQG or Treadwear ratings of a tire. The individual customer reviews of the tire can also be somewhat insightful, but I tend to take them with a grain of salt and use them as a secondary factor to TireRack’s rating system.
As you start comparing different tires, it’s important to verify the TREAD WIDTH of each model, and if they run too narrow or wide, shop to see if a slightly different size would be more applicable. If you are trying to break track records, further research would be beneficial but keep in mind that a review from a Lotus Elise owner on a set of tires probably won’t be as applicable on a heavy GTR or CTS-V, so try to find comments from someone with a car of similar weight and tire sizing.
I am not going to outright say buy this tire, or that tire sucks, but by now you have gained enough knowledge to make a more educated decision on your next set of tires with greater confidence that not only will the tires be more likely to fit, but will deliver the performance that you are looking for.