Breathe in. Breathe out. Your fingers flex around the wheel. Your feet twitch on the pedals. Your eyes dart between the track ahead, and the signal holding you back. The light changes, and in the blink of an eye you spring into action! Your foot slams the accelerator, tires scream as they spin, and spin, and spin, helplessly seeking traction that isn’t there to be found. You sigh, let off the gas, and you realize it just isn’t going to work. You need track tires.
When it comes to track performance, there’s rightfully a great deal of focus on the chassis construction, the powertrain, and the suspension. These are the factors which one considers when buying a particular vehicle. There’s also a ton you can do to improve performance once you’ve chosen the car. But for all the attention paid to turbochargers and coilovers, arguably the most significant impact you can make also comes from one of the easiest things to change: the tires. So now that you’re here to investigate what kind of track tire is right for you–from 200 treadwear (“200TW”), to drag radials, to racing slicks–let’s come to grips with the car’s most important consumable.
Performance Tires: A Brief History
John Dunlop is credited with inventing the pneumatic tire in the late 19th century. Dunlop tires won the first running of the 24 Hours of Le Mans in 1923. As a brand-new science, tire design did what it could to keep up with the rest of the automobile in the ensuing decades. Tires in the 1930s and 40s were made of cotton and tree rubber. Breakthroughs, such as the switch from cotton to nylon in 1958 (reducing weight by 33%) and the introduction of synthetic tread compounds, improved acceleration, grip and tread life. Tread patterns for dealing with water, mud, and snow were implemented and refined. Smooth tread designs were also identified as the best way to attain maximum traction on a smooth and dry surface, like a race track.
Dunlop’s first “racing slick” arrived in the late 60s, shortly followed by Michelin and Pirelli. Michelin’s radial-construction slicks won half the F1 races they participated in from 1979 to 1984. At the same time, Dunlop had withdrawn from F1 to focus on developing road tires, recognizing that the optimal tire designs for either environment were diametrically opposed. Since then, science has gone wild on tire technology.
The Impact of Choice
The construction of the tire, cut of the tread, and properties of the rubber are all highly variable factors contributing to performance. It’s literally the difference between having traction and being stuck. That’s why serious off-roaders use all-terrain tires, or why proper snow tires are always recommended for cold climates. (I was told by one who completed a Master’s degree studying tire traction that if you had to take on a snowstorm and could choose between winter tires on a 2WD car or all-seasons paired to AWD, take the Challenger with Blizzaks every time.)
From a track performance standpoint, the selection can mean entire seconds off a lap time. For racer Randy Pobst on an unidentified track, the difference between high performance road tires and racing slicks was a full six seconds! I’ll cover the details of what 200 treadwear tires, drag radials. and racing slicks are and what they’re best used for in detail, but for the nutshell version:
200TW tires are usable on-road, and come in a wide variety of designs which are optimized for specific purposes. Use if you want to track your daily tires.
Drag radials maximize straight-line acceleration with modest roadgoing capabilities. Use as the sole tire on a low-use, warm-and-dry weather performance vehicle.
Racing slicks get the most grip on-track, period, but are basically useless (and usually illegal) on road. Use to get the absolute most out of your car on track, if you don’t mind the time and cost to replace and swap them.
200 Treadwear: Running Shoes for the Car
The optimal performance tire for most enthusiasts is likely the “200 treadwear” variety. This is a class of tire characterized less by its absence of tread and more by the grip of the compound. The name comes from the performance of the tire in a standardized test, relative to a controlled reference. The control tire is assigned a treadwear rating of 100, and all other tires are rated according to how quickly they wear out by comparison. A 200 rating is assigned for wearing half as fast, indicating a tread life twice as long as the control tire.
The 200TW class of performance tire is completely roadworthy, but not road-optimal. For example, the road-only tires I’ve got on my cars have a treadwear rating over 600. But some of the most famous tire names in the sports car world, like the Continental ExtremeContact Force, Michelin Pilot Sport 4S, and Michelin Pilot Sport Cup 2, all fall in this category of tire. Clearly, though the 200TW class makes some compromises on longevity, the sacrifice pays dividends in the name of grip.
Grip is produced by two mechanisms in a tire: molecular adhesion (literally “stickiness”) and conformance of the rubber to the road. Improving performance in either characteristic is going to reduce treadlife. A stickier tire is more likely to release small particles as it rolls under load, and to conform to the road, a tire must be softer, making it inherently more susceptible to breaking down. It’s primarily the softer compounds used to improve grip which limit the lifespan of a 200TW tire compared to average road tires. But on the other side of the coin, these features mean faster launches, harder corners and lower lap times.
The variety of 200TW tires is enormous. There are entire subcategories optimized for running autocross, time trials, track days, or street and track combined. Depending on what you’re planning to do, you’ll want to emphasize different performance characteristics in your tire choice. Events like autocross and time trials don’t give a lot of time for tires to warm up, which softens the rubber and improves grip. Believe it or not, some tires warm up faster than others, making them ideal for this application. On the other hand, if you’re running a track day, where you’ll have plenty of warm-up time, prioritize heat resistance and a low wear rate instead. With a good rating for performance in the wet, such a tire would even be suitable for the daily commute.
You’ll be absolutely spoiled for choice if this is the way you want to go. Since it means you can run track events without necessarily needing to change tires, why wouldn’t you? The answer, of course, is that while 200TW tires are less performance-compromised than your typical all-seasons, they still make significant concessions in the name of road-worthiness. If that’s just not going to cut it for you, then you’ll want to think about…
Drag Radials: When Every Tenth Counts
You’ve seen pictures of a top fuel dragster tire just at the moment of launch, right? Where the tire’s getting all screwed up, wrinkling like crazy from the earth-shattering torque through the axle? That’s a characteristic of a “bias-ply” drag tire, with a structure of nylon wrapped in an X-pattern over the core. It works well on many surfaces, but all the power going into twisting the tire is temporarily failing to propel the vehicle forward, costing precious hundredths of a second. Enter the drag radial.
With a radial construction (steel belts wrapped from bead to bead), the sidewalls become much stiffer. This reduces that wrinkle effect significantly, at the cost of making it harder to put power down. Slip during the launch becomes far more likely. Still, the benefits are plentiful. Drag radials are often street legal thanks to a little bit of grooving. They can handle a turn at driving speeds, and assuming you can get them to hook up (they don’t need massive burnout to warm them up, either), they’ll be your ticket to the fastest possible quarter mile times.
Still, don’t get them confused with 200 treadwear. Drag radials are more like 20-60 treadwear. You’d be lucky to get 5,000 miles from a roadgoing set of these bad boys. And though they can handle street driving and minimal wetness, they’re nowhere close to proper road tires. My advice is to keep them off the street unless you’ll only be driving them in warm and dry weather, and even then only if your annual mileage is quite low. What’s the point in a set of drag radials that you wear out on the road before they ever see a track?
Still, if you insist, the word is that Nitto’s NT555 RII is an excellent roadgoing drag radial with a 100 treadwear rating. You might even pair them with 200TW tires for the unpowered axle for an even more robust road-and-track setup. On the other hand, you might turn to strictly racing-oriented brands like Hoosier and Mickey Thompson for highly effective track-only drag radial, or their superstar counterparts.
Racing Slicks: The Absolute Limit
The racing slick is so effective that for a whole decade, Formula One banned them to reduce track speeds. Read that again. Formula One thought that racing slicks were too fast. Need I say more? .(Don’t worry, I will).
The idea of a perfectly smooth tread was first developed in the 1950s drag racing scene. The design results in the absolute maximum contact area between the tire and the ground. All other things being equal, that results in more grip than a grooved tire on a warm, dry surface. A slick won’t deform much because there are no gaps in its structure for rubber to flex into. It can get away with using much softer compounds that dig into the nooks and crannies of a smooth racing tarmac, maximizing both mechanisms by which grip is produced.
With a large, stiff sidewall allowing the tire to flex during hard cornering, the design is generally optimized around maintaining both lateral and longitudinal grip. Racing slicks are simply the best way to minimize a lap time. Drag slicks are a minor exception, as they don’t worry about lateral (cornering) performance and instead go all-in on supporting short bursts of massive straight-line acceleration, and I’ve already covered how drag radials can eke out a faster time, but you get the gist.
There’s no scenario where a racing slick, even one that has somehow obtained road-legal status, is a good idea to take on the street. Rough surfaces, the occasional presence of puddles, abysmal cold performance (which matches the description of most road driving), and catastrophic treadwear ratings all work against you here. These tires are for one thing and one thing only: the track. Do not waste your money or risk your safety to drive them on the street.
Improving Performance in a Pitstop
There you have it, track tires in a nutshell. If you’re super hardcore and have a trailer just for tires, racing slicks will get you the most straight-up performance. If you’re considering taking your track tires on the road, or have a very specific drag scenario that you’re trying to master, then perhaps drag radials will be the way to go. Most likely, you just want the best tire that you don’t need to change twice per track day, in which case the 200 treadwear class of road tires will be a perfect fit for you. There’s lots to choose from, but this breakdown should help hook you up with the best tires for getting your power hooked up to the road. May the best tread win!