Say hello to Potenza RE-71RZ, Bridgestone’s latest entry into the Super 200 tire category that is so popular in our amateur motorsports world. Its predecessor, the Potenza RE-71RS, already sat at the pointy end of the field with tremendous grip in both dry and wet conditions. The new model aims to push that bar even higher.

We first heard that changes were afoot in the Potenza line back in the spring and even saw a picture of the new tire. Its tread pattern was clearly a relative of the RE-71RS with its characteristic diamond-shaped voids, but the wide outside shoulder and offset center rib were notable differences. This moved it one step further away from its street-oriented roots and closer to track-specific use.

Since then, information has been scarce up until this week’s press release. We just had a download session with Bridgestone and can now reveal even more details. Here’s what we now know.

Bridgestone Potenza RE-71RZ Changes

Bridgestone says that the RE-71RZ is faster, more consistent and longer lasting. What is this sorcery? One word: silica.

New compounding advances with engineered particles of silica and polymer–dubbed NanoPro-Tech–promise quicker pace for a longer duration but also better durability.

The big advance with the outgoing RE-71RS versus its RE-71R predecessor was the addition of more silica via new mixing methods. The RE-71RZ takes this concept further with adaptations at the molecular level to better disperse that extra silica.

Why silica? This simple substance, most commonly found in glass, enhances durability and wet grip when added to tread cap rubber. Further, some of that newfound durability can then be used to alter the typical tradeoff between dry grip and longevity. In the end, it’s a win-win-win situation.

The tread design has also changed to a more solid outer half–improving dry performance–while retaining wide longitudinal grooves on the inside for water evacuation. We’ve seen beveling and heavy graining of the center rib on the outgoing tire, so the new design should mitigate that tendency.

And finally, the carcass has been modified internally to more evenly distribute loads across the face of the tire to keep operating temperatures optimal for sustained grip. This should also help resist localized graining.

This graphic compares the cornering loads between the RE-71RS and RE-71RZ.

These changes do have a slight downside in added weight. Some of this is simply the additional rubber of the reduced void area, and the rest comes from added carcass stiffeners needed to retain quick steering response, a hallmark of the RE-71 line.

Bridgestone Potenza RE-71RZ Performance

Bridgestone claims both dry and wet lap time improvements of 0.75 second over the outgoing tire on a track-prepped Toyota GR86 at the famed Tsukuba Circuit, home of Japanese Time Attack. That’s a solid improvement on a lap time of about a minute.

Bridgestone Potenza RE-71RZ Sizing and Availability

While the introduction timing was geared towards the Japanese home market, Bridgestone was quite aware of the SCCA eligibility deadline here in the U.S. As such, they jumped through quite a few hoops to have plenty of inventory–some 6000 tires across 18 sizes –available for sale on December 31 to meet SCCA Solo and Time Trial eligibility rules.

The full slate of 45 sizes will be stateside by February 1, company officials told us, in time for most people’s needs. This includes new larger sizes not previously available in the RE-71RS–most notably 315/30R18, 335/30R18 and 325/30R19.

Those wider sizes will feature an additional center groove to help with stiffness and water evacuation.

Bridgestone Potenza RE-71RZ Pricing

One thing that is not expected to change much is pricing: You’ll be getting all of this newfound performance for a similar cash outlay. Price increases of only 4-6% are typical across the sizing range.

Bridgestone Potenza RE-71RZ Testing

Color us excited by all of this. We are stoked to have sample production tires inbound to put through our typical testing program. We’ll be comparing against both the outgoing tire and other suitable market competitors. Expect those results to be public by the first of the year.

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