Place your palm on the ground. Feel the amount of square footage you cover?
Now, imagine a linebacker is pushing on you, and all you’ve got to keep from sliding is that one handprint’s worth of traction.
Multiply the grip by four and the weight by ten and you’ve got some idea what it’s like to be your car.
Modern cars are chock-full of safety aids: anti-lock-brakes, traction-control systems, vehicle dynamic assists, multi-link suspensions, torque-splitting all-wheel-drive. Wonderful stuff, all of it, but next-door to useless if you don’t have the grip.
Put another way, Olympic decathletes only put on high-heels or oxfords for the awards banquet; the rest of the time, they’re wearing track shoes.
Now, you may be thinking since you’ve already ponied up the cash to buy a performance car, the manufacturer has surely shod your steed with the best tires money can buy. Hardly.
While Ferrari and Porsche are no-doubt shoeing their sports cars with the best rubber around, most other carmakers are building to a budget. That means taking bulk discounts on what might be a pretty good tire, but not exactly top of the class.
Need an example? How about the current 5.0-litre Mustang? Even with the optional track package, it can be a bit squirrelly on those all-season Pirellis.
All-seasons are no-seasons
Everybody knows how useless an all-season tire can be when the snow really starts flying. As the old saying goes: jack of all trades, master of none.
All-season rubber just doesn’t have the soft compound that can handle low temperatures.
All-seasons also lack the sidewall rigidity of a high-performance street tire, and are nowhere near as sticky when the temperatures get hotter. It’s simply asking the tire to be good at too many jobs, leaving no room for the specialization that high-performance tires require.
Keeping a low profile
Checking the sport option on any car usually comes with a “plus one” to the size of the rims equipped. Granted, these larger wheels give your ride a better look, but there’s a handling aspect to be considered as well.
While the diameter of the rim increases, the overall diameter of the wheel and tire package stays the same. That means that the percentage of the wheel that’s squishy rubber is somewhat reduced in favour of inflexible alloy.
Imagine that your shoes were soled with pneumatic material and you’ll see what’s going on here. At a higher-profile, you’re essentially trying to balance on a set of moon-hoppers. Drop the side-profile to just a few inches, and you’ve donned a pair of Nike Airs instead.
What’s more, modern high-performance tires will have added stiffening agents in the sidewalls to prevent flex under heavy cornering loads. In some cases, this can create a rough ride – think of BMW’s very stiff run-flat tires – but the trade off is sharper-feeling steering and more reactive handling.
Hotter laps through stickier rubber
If you’ve ever seen a racecar open to the elements, with all that spidery suspension glittering like a coiled, metallic endo-skeleton, you may think the first thing to do to get your Civic to turn a quicker lap is to lower the car.
After all, a lower centre of gravity feels faster, and most modern racecars are inches off the ground.
It might look cool, but suspension tuning is secondary to good tire grip. In fact, proper suspension tuning is all about trying to keep the tire’s contact patches as best aligned to the road as possible. There’s nothing the best set of springs and shocks can do if the tire grip isn’t there.
A good example of a car that’s already set-up for race-track battling but could benefit from some stickier shoes is the new lightweight, rear-wheel-drive coupe built jointly by Subaru and Toyota.
The Subaru BR-Z (or Scion FR-S) comes standard with the same type of rubber as the Toyota Prius! Great for low-friction fuel savings, not so great at the track.
Just changing over to a proper set of rubber will have the little tyke out-cornering more powerful machinery that can’t get the power down.
Fair-feather friend, wet-weather warrior
Not all high-performance tires are created equal; some are better overall, and some are good at one thing and not another.
If you live on the wet West Coast, buying a high-performance tire with big sticky tread-blocks can come with a pretty severe drawback. In the rain, fatter tires are prone to hydroplaning, and the fewer rain-channels a tire has, the worse it handles the rain.
But the more squared-off tread blocks a tire has, the closer it is to being the king of performance rubber: the racing slick.
Naturally, any street tire is going to be a compromise over a racing application, but there’s a sliding scale depending on how long you need your tires to last, what kind of weather you’re likely to use them in, and whether you’ll be performing in competitive driving like auto-cross.