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Track Tests and Cheater Tires

That record lap time may not have been set on factory-stock rubber

Performance car lap times are prime fodder for automaker marketing departments—just witness the frenzy that occurs when someone sets a new Nurburgring Nordschleife record. But the tires used by the cars that post these laps sometimes cloud the true picture.

Automakers tend to work in conjunction with tire companies to develop model-specific tires for high-performance vehicles. Sometimes they choose more than one brand of tire. Take the 991.1-generation Porsche 911 GT3, which came fitted with Porsche-specific versions of the Michelin Pilot Sport Cup 2 or Dunlop Sport Maxx Race. (It was a lottery whether your 475-hp two-seater came with the Dunlops or Michelins.) Both “streetable track & competition” tires, as the TireRack describes them, sacrifice tread life and wet-weather capability in exchange for quicker laps.

Some manufacturers let buyers choose between either a track-oriented tire or a road-and-rain-friendly setup. That’s the case with the likes of the Ford Focus RS, Aston Martin V12 Vantage S, and McLaren 570S. Sometimes the choice is free; sometimes the buyer has to pay a premium for the stickier tire. The key is that all are OEM tires fitted to the wheels before the car leaves the factory, and all are listed in the order guide/online configurator or in the relevant dealership’s computerized ordering system.

This isn’t always the case with test cars the media uses. In recent tests by two different publications, the three top-finishing cars in one test and two of the three quickest cars in another comparo wore tires that don’t seem to be available, at least today, from the factory.

One is the Ferrari 488 GTB. I found no place in Ferrari’s online configurator, dealer price guide, or dealer order guide where you can spec a track-focused tire. Additionally, TireRack’s website doesn’t list the Michelin Pilot Sport Cup 2 “K1” (Ferrari-spec tire) as an OEM tire for the 488. I called a Ferrari dealership and it confirmed there is no optional track tire for the 488. If a customer wants that stickier rubber, the dealership is happy to order a set through its parts department and install it after the car arrives from the factory.

The no-longer produced Ferrari 458 Speciale came with the “K1” Cup 2 tire, but the 488 GTB is fitted with either Pirelli P Zeros or Michelin Pilot Super Sports when it leaves Italy. But those weren’t the tires that were on the turbocharged, mid-engine Italian when it ran lap times for various magazines in 2016 and 2017. It’s the same case with the Porsche 911 Turbo S and Acura NSX—you can order stickier tires from TireRack or through the dealer, but the cars don’t leave the factory with the track-friendly tires.

Another car is the Mercedes-AMG GT R, but the story differs slightly. Mercedes sent that car to recent track comparisons with a different variant of its standard Michelin Pilot Sport Cup 2s. Instead of the Mercedes-Original (MO) designation, these were stamped “TPC,” which is an OEM designation for General Motors—this AMG GT R wore the OEM tires for the Corvette Z06 and Corvette Grand Sport with the track-oriented Z07 package. GM’s version of the Michelins is more dry-weather focused than Mercedes’ is. The TPC tire is also 10 millimeters wider front and rear—and, curiously, a run-flat design.

I have no issue with Mercedes offering the GM-spec tires, but it’s not clear how a buyer actually obtains the focused Corvette tires directly from the OEM. A friend of mine would like to spec the stickier tires on a GT R he is ordering but he can’t seem to figure out how exactly to do that. The gooey rubber isn’t listed online on the Mercedes-Benz USA website, it doesn’t appear in the official dealer order guide, and my local Mercedes-Benz dealership can’t find it in its ordering system for the GT R. However, a contact at Mercedes told me the option will be added soon and that the order code and pricing aren’t yet finalized.

Automakers will keep playing this tire game as long as it benefits them. Ideally, testers should demand that any tire that’s fitted to a car for a test is available on the car when it leaves the factory. But since car companies are allowed to fit whatever rubber they want as long as it’s street legal, we’ll just have to keep a close eye out for cheater tires.