Goodyear Eagle F1 Supercar

The '92-'96 ZR-1s and GS Coupes used the Eagle GS-C, Goodyear's second-generation, ultra-performance tire which debuted in September, 1991. GS-C was cutting edge stuff in the early-'90s, but tire technology advances quickly and by the mid-'90s, the GS-C, while still a decent performance tire, was up-staged by better performing products from other manufacturers. For about the next five years, Goodyear did not produce its best performance tires in 315/35ZR17. In 1997, it considered releasing the Eagle F1-GS, the non-EMT, replacement version of the OE C5 tire, as a 315, but never did. The next opportunity came with the F1 Steel, introduced in February, 1998. A year later, as a result of a survey conducted on the VetteNet and ZR1 Net along with suggestion from an unlikely source: Corvette Chief Engineer, Dave Hill, Goodyear began developing a 315 F1 Steel. Unfortunately, just before production began in mid-1999, the molds for the 315/35ZR17 F1 Steel were destroyed in a shipping accident. The cost of new molds was not budgeted because the F1 Steel line was going to be discontinued in early 2000.

All this time, if ZR-1 and GS Coupe owners along with others who adapted the 315 to their cars wanted to use Goodyear tires; they had to settle for the GS-C which, by 2000, was three generations removed from the best ultra-performance radials Goodyear had to offer.

In the meantime, Goodyear, working with the Corvette Development Team at GM, designed yet another ultra-performance radial, the "Eagle F1 Supercar," as the OE tire on the 2001 Z06. A good measure of the Z06's astonishing abilities in the hands of performance drivers came from the F1 Supercar which set the bar incredibly high as far as dry traction and at-limit predictability from an OE tire. Towards the end of '01, rumors leaked out of Goodyear about a replacement version of the F1 Supercar in 315. In the Spring of '02, the wishes of many ZR-1, Grand Sport and other C4 owners finally came true, when Goodyear released the F1 SC in both 275/40ZR17 and 315/35ZR17.

Serious performance drivers can breathe a sigh of relief. The replacement version of the F1 Supercar is not a run-flat. The Z06 mandate--cutting-edge handling--required giving up the convenience of an Extended Mobility Tire (EMT) because of its weight and other compromises necessary in an everyday tire for other C5s. Typically, when a tire company makes a replacement version of a tire they sell to OE manufacturers, they simply take the OE design and enlarge it or shrink it to the required size. Well, Goodyear didn't see it that way.

"We were OE on the ZR-1," Bob Toth, Goodyear's Brand Marketing Manager for Automotive Tires, reminded me. "Matter of fact, we've been, proudly, OE on Corvette for a long time...since 1978. So when we benchmark (the OE Z06 Supercar) against our own tire ...the OE-tuned tire for that model(the GS-C on ZR-1s)... we very-well knew how it performed and what it could do."

This benchmarking process was run by a group of tire development engineers led by Ben Sluder. On the basis of input from Sluder's group arising out of that testing, Goodyear's Tire Technology department decided, for the replacement version of F1 Supercar, it would, using the Z06 tire as a starting point, develop a slightly different version of it for both C4 and C5 base applications.

I spoke to Ben Sluder to get some specifics of what makes the F1 SC replacement tire different from the OE Z06 version. "We got the Z06 tire from the OE guys," Sluder told me, "and ran it through some benchmark testing, using ZR-1s, primarily, but we also had a base C5 on which we tested, as well. We felt, when used on those platforms, there were areas of the tire's performance envelope could improve. We ended up making some modifications to tread design and construction tuning, mainly belt angles and ply. The goal was to tighten it up and make sure it performed very well on those two platforms. We tweaked the tread design, brought some development molds in, built more tires, ran them on our test track then kept tweakin' the construction until we got it where we wanted it. That's kinda why the launch of the tire was delayed for a little. We wanted to make sure we had it right."

"The changes centered around belt angles and how they affected the handling of the tire." Sluder continued. "We lowered the belt angles a little bit from the Z06 construction. We also tweaked the tread contour slightly...some of the blades and some of the grooves...to alter the tire's wet traction slightly such that it was better suited to the C4 ZR-1 and C5 base applications."

When a radial tire is generating high lateral acceleration, the outer half of the tread does most of the work. The stiffer that part of the tire is, the more the tire will grip and the more predictable the quality of that grip will be. Compared to the GS-C, the F1 Supercar has a softer tread compound and different type of asymmetric tread pattern having larger, stiffer blocks along with, on the outer half of the tread, less and more shallow water channels. The combination of these features make the Supercar a tire with exceptional grip. Expectedly, the F1 SC's dry traction is a substantial measure better than that of both the GS-C and the C5s F1 GS EMT.

"The Supercar compound," Goodyear engineer Becky Rickman revealed, "is specifically formulated for max lateral grip and dry handling, while maintaining good wet grip. The Corvette replacement sizes (275/40ZR17, P315/35ZR17, 245/45ZR17, and P275/40ZR18) will utilize the same tread compound as found on the C5 Z06 Supercar OE application. This compound has substantially higher overall grip than the GS-C as we have had to continually advance our technology in order to meet GM's stringent requirements for max dry performance. The SC compound is tuned for predictable and forgiving handling at driving limits."

For a tire to work in the wet, tread blocks need to be smaller and water channels plentiful. The inside half of the F1 SC's tread meets that criteria and provides wet traction that is acceptable but not quite as good as that of the GS-C or the F1 GS EMT. Lastly, Sluder told me that the F1 Supercar is quieter and it looks better that the GS-C.

About a four months ago, I put a set of F1 Supercars on my '95 ZR-1. I had the work done at Tucker Tire Service Co, a Goodyear dealer in Covina, California because, in the past, they have proven very careful, during the tire dismounting/remounting process, to avoid damaging the C4 LTPWS sensors which are easy to break and difficult and costly to replace.

During some initial around town and highway cruising, I didn't notice a heck of a lot of difference between the Supercars and the GS-Cs I took off, except a slight increase in high-frequency impact harshness, a sign the SC's casing was a bit different than that of a GS-C, and a little less noise.

About a week later I made a fast run over California Route 2 and L.A. County Route N3 through the San Gabriel Mountains north of Los Angeles...the famous Angeles Crest/Angeles Forest Highways...to the high-desert city of Palmdale. A couple of weeks after that I was on a test trip from Los Angeles to Santa Barbara, California, which took me through the mountains west of Oaji on State Route 150. Again, I was running the Supercars pretty hard.

Three things I noticed on these drives were: 1) more grip, which extends the car's limit just a bit, 2) steering response seemed just a tiny bit more crisp and 3) the Supercar is a little easier to run right at the limit because it breakaway is just slightly more predictable. All three of these are excellent improvements in the qualities high-performance drivers need in an ultra-performance tire.

The most important points of this review are: 1) the new Goodyear Eagle F1 Supercar is available in 315/35ZR17, which finally, gives ZR-1 and GS Coupe owners the best Goodyear has to offer, 2) the F1 Supercar is a significant improvement over the GS-C and F1 GS EMT in dry traction and steering feel at the limit and 3) I have not run Pilot Sports or T/A KDs on my car, but I've had numerous conversations, some quite detailed, with people who have put them on ZR-1s, Grand Sports, other C4s and C5s. Based on those discussions, my opinion is the Eagle F1 Supercar is a better tire an aggressive driving environment than both the Michelin Pilot Sport and the Goodrich T/A KD. That makes the F1 Supercar an outstanding ultra-performance tire for a ZR-1, Grand Sport Coupe or most C4s with 17-in. wheels and all '97-'03 C5s not equipped with Z06.

Five times since the early-'80s, Goodyear, the only major tire company that's American owned, has developed OE tires for the Corvette: 1984, for the 1984 Corvette, 1990 for the rear of the ZR-1, 1992 for all C4 Corvettes, 1997 for the C5 Corvette and 2001 for the Corvette Z06. With the replacement version of the F1 Supercar, Goodyear continues its support of the American icon that is the Corvette by, for the first time, designing a specific replacement tire for an existing Corvette model, the ZR-1.

The replacement version of the Eagle F1 Supercar is available in the following sizes: P245/35ZR18, P335/30ZR18, 255/40ZR18, 295/35ZR18, 215/45ZR18, 275/40ZR18, P225/40ZR18, P265/40ZR18, P315/40ZR18, 315/35ZR17, P265/40ZR17, and 245/45ZR17. These tires are a perfect match for C4s with Z51, Z07 and ZR1. Most '88 or later C4s with 17-inch wheels are supported, including all ZR-1s and all Grand Sport Coupes. The only sizes not offered are those used by '93-'96 base cars, '93-'96s having base suspensions with FX3 or F45 ride control systems or Grand Sport Convertibles. In addition, the replacement F1 Supercar fits '97-'03 C5 Coupes, Convertibles and '99-'00 Hardtops.

For more information about the Goodyear Eagle F1 Supercar see your local Goodyear dealer. For those residing in the San Gabriel Valley or the Inland Empire areas of Southern California: see Tucker Tire Co., 612 N Azusa Av., Covina CA 91722. Tel: 626 332 1142.