Tire Talk: Competition tires have bite but fun drive comes at a price

Tires that have a motorsports cap (outer layer of rubber) tend to tramline. So you will be very busy in the steering whenever you encounter any ruts or ridges in the road.

  • Mazda-Miata

I have an older Miata that needs tires. Your suggestions of the Hankook V2 and Dunlop DZ101 are both back-ordered with no word on when they will be available. My dealer suggests the Falken ZX912 ($115) or the Falken RT615 ($160). The RT615 looks like an interesting performance tire; have you had any experience with it?

I have not driven on either of the Falkens, but here is what I can tell you: Both are well-regarded and get good consumer reviews. The RT615 is a competition-type tire, so it will have tons of grip but it comes at a price.

Sometimes, lots of grip is actually too much. Tires that have a motorsports cap (outer layer of rubber) tend to tramline. So you will be very busy in the steering whenever you encounter any ruts or ridges in the road.

This class of tires also have a shallower tread depth than a regular high-performance tire, plus they wear faster. All that extra grip has to come from somewhere. Since they have shallower tread depth to begin with and wear faster, you will find they are not as good in the rain.

Lastly, to keep the tread face flat at all times, the sidewalls of these tires are considerably stiffer, and ride quality suffers.

One more caveat, these tires take a while to warm up, so you will find them quite stiff and square feeling until they have been driven for a while after any long period stopped. It could be a several kilometers before they smooth out again. This will be worse when ambient air temperature is lower.

Also, the RT615 is a discontinued tire, so when this inventory is gone, they are gone. It is being replaced by the RT615K.

You cannot mix the 615 and the K on the same end of the car. So if you damage a tire, you will have to buy two replacement 615K tires. Or you can just buy the newer model now.

On the plus side, the grip levels are just plain fun. So depending on your driving style, they may be a hoot. Or the negatives could dull the fun of driving.

Over the years, I tried many competition tires for daily driving, and they have been crazy fun. But after a long drive, you feel beat up.

The Miata has a very compliant suspension, so the ZX912 may be happier in the long run. But in the short run, there is something truly thrilling about driving a motorsports spec street tire that has more grip than you can ever use.

I can?t help responding to the bad advice you gave to a BMW owner regarding rotation of his Bridgestone RE050 tires. As he states, the tires are staggered fit, so they can?t be rotated front to back. You advised him to rotate left/right. What you failed to take into account is that these are directional tread tires. Changing their direction of rotation will compromise performance and safety. Bad advice!

The tires are directional, but they can be switched side to side by removing them from the rim, reversing them and then put them on the opposite side of the car. The tires are symmetric; the only tires you cannot rotate would be directional asymmetric tires.

I have asked several mechanics and have not had a satisfactory answer to my question, so I turn to the tire expert for the definitive answer. Apart from a thorough wash before storage, should you treat the tires with a protectant such as Armor All? I store my tires in a cool wine cellar. Is this good enough or should I add rubber treatment?

Please do not put any tire treatment on your tires. Tire treatments range from formulas that eat your tires to ones that just dry them out. And rubber drying out is what causes tires to lose their grip on the road. Any treatments that are petroleum based are especially bad.

Just wash your tires with soap and water, make sure you rinse well, dry them or wait til they are dry, put them in plastic bags, tie the bags closed and stack them up on their sides.

If the tires are on wheels, make sure all brake dust is washed off the wheels. Your wine cellar is the perfect environment, with a steady cool temperature.

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