New Non-Run Flat for C5s

And...it's an All-Season Tire

by Hib Halverson
©2007 Shark Communications
No use without permission
Released:  September 23, 2007

Image: Goodyear Tire and Rubber Co.

In July of 2007, Goodyear introduced, a new, ultra-performance tire called the "Eagle F1 All Season". Its debut marks the first time the Akron-based company has had an all-season product in its F1, ultra-performance line. The first 22 sizes were released in July and another 16 sizes are coming in a staggered release, in Q4, 2007. These 38 sizes fit a large number of performance sedans, sports coupes and sports cars including "the non-Z" C5s. The C5 front (245/45ZR17) is available now and the rear (275/40ZR18) will come by the Fall. This new product from the sole remaining large American tire company, is not a run-flat tire and provides another option for C5 owners not wanting to use EMT tires.

The F1 All Season is the debut of carbon fiber technology in an ultra-performance application. "CF" is familiar to Corvetters as the material used for the '04 Z06/Z16 hood and the '06/'07 Z06 front fenders, wheel wells and floor. In this new tire, CF is in a different form, as carbon fiber reinforcements in the sidewalls which stiffen the tire to improve steering response and handing. This tire also brings DuPont Kevlar into ultra-performance tires after Goodyear introduced it in the Eagle "ResponsEdge" performance touring tire in 2006. In the F1 AS, a layer of Kevlar just below the tread, makes the tire's structure more rigid.

During a preview event last May at Daytona International Speedway, the Corvette Action Center talked to Bob Toth, Goodyear's Marketing Manager for Auto Tires, the guy who developed the "Eagle" branding concept back in the early '80s and one of Corvette's biggest supporters inside Goodyear. "Our Eagle F1 line has always been synonymous with great dry traction, precise control and crisp steering response," Bob told the CAC. "Our award-winning F1 GS-D3 brought those attributes to wet roads. The Eagle F1 All Season extends that envelope by offering traction on dry, wet and snow-covered roads. These new, Eagle 'Carbonfibers' enable enthusiasts in places which experience occasional subfreezing weather to drive their Vettes or other performance cars all year long, if they choose."

Cutaway of the F1 All Season. Image: Goodyear Tire and Rubber Co.	At Goodyear's Proving Ground in San Angelo, Texas there is a glass plate facility which allows imagery of tires rolling through an .080-inch thick layer of water at high speed. In this image of a Eagle F1 All Season, you can see how Goodyear's famed "Aquachutes" channel water away from the tire's contact patch. Image: Goodyear Tire and Rubber Co.

Using the "tread zone" idea Goodyear pioneered in its "Assurance Triple-Tred", an F1 AS has a directional, "dual-zone" tread. For wet traction, there is the "All Season Zone" which combines: 1) famed "Aquachutes", which channel water from under the tread and away, 2) "micro grooves" each of which has a "biting edge" to enhance traction on snow or ice, and 3) a silica tread compound unique to this tire and designed for improved traction in subfreezing conditions. The All Season Zone enhances traction on snow and ice to the point that this tire is what some might call a "soft" all-season tire. It's certainly not for frequent and regular use in deep snow and heavy ice conditions but, if you drive your Corvette or other performance car every day, do so in a place where, in the winter, you might start home from work and get caught in a modest snow fall or find the roads a little icy from a sudden temperature drop; this tire will help you get there...and get there in a more safe manner than will other performance tires.

The Author at speed on Goodyear F1 ASes, in a slalom, during a rainstorm at Daytona International Speedway in May of 2007. Image: Goodyear/Aaron Vandersommers.

Two of this new Goodyear's competitors are the Michelin Pilot Sport A/S and the Bridgestone Potenza RE960AS Pole Position. The executive summary of test data Goodyear supplied is that the Eagle F1 All Season is comparable to both in dry traction, has better lateral grip and much better acceleration and braking performance in the wet. At Daytona back in May, I had a chance to test those three tires against each other. This testing was not done with a Corvette, because this new tire was not yet available the C5 rear size. It was with a couple of rear-drive, performance coupes, a Mazda RX-8 and an Infiniti G35, along with a Pontiac Solstice. In an autocross and on a short road race course in the wet-and this was a rainstorm, not on a watered-down course-I found the new Goodyear had better steering response and lateral grip than both the Bridgestone and the Michelin, and the improvement over the Pilot Sport A/S was significant.

Our tire testing HHR. It has the 2.4L 175-hp engine, five-speed manual, sport suspension and 17-in wheels with Firestone Firehawk GT03s. Image: Author.

Wanting a more lengthy test period but unwilling to wait until the end of the year to try this tire in a street driving environment, I decided to put a set of F1 AS tires on an '07 Chevy HHR I have in my fleet. While the HHR is not a hardcore performance car, it was ordered with all the performance options one can get: handling suspension, 17" tires on aluminum wheels, five-speed manual and the optional, high-performance engine. Since I have to wait until the end of the year to get my hands on a set of Eagle Carbonfibers in the base C5 Vette sizes; a head-to-head comparison with the Firestone Firehawks previously on the HHR, will suffice for now.

We arrived at Tucker Tire Service to find four spanking new F1 All Season waiting for us. Image: Author.	At Tucker Tire Service, Bernie runs the mounting machine. He's been at Tucker for a long time and knows every aspect of mounting performance tires on alloy wheels. One reason we use Tucker for all our tire work is its skilled staff. Image: Author.

I took the HHR to Goodyear dealer, Tucker Tire Service Company in Covina, California and had them replace its Firestone Firehawk GT03s with Eagle F1 All Seasons. I had just come off a 2700 mile trip from Tom Henry Chevrolet in Pennsylvania, where I bought the truck, to California, so I had a lot of highway driving experience with the HHR. It only took about five miles on nearby Interstate 210 for me to perceive one feature of the Goodyear: a noticeable improvement in on-center steering feel. With the Firestones, the car's tracking felt vague and constant, small steering inputs were required to correct the car's path during highway driving. After changing to the Goodyear, on-center feel improved modestly and the car's straight-line tracking improved greatly. The main reason for the difference in tracking is the F1 All Season tread's stiff, continuous center rib, which the Firestone lacks.

The main enabler of the Goodyear's better on-center feel and the car's more accurate straight-ahead tracking is the stiff, continuous center rib on it's tread. The Firestone (right) does not have as robust a center rib. Image: Author.

As far as noise and harshness, this new Goodyear is a mixed bag. It makes noticeably less tread noise compared to the Firestone Firehawk GT 03, but there was a slight increase in ride harshness which I'd characterize as noticeable, but not uncomfortable or annoying. The noise decrease comes from the F1 AS's variable-pitch tread elements. The harshness increase is a function of the two tires' different speed ratings. The Goodyear is Y speed rated, whereas the Firestone's is T speed rated. To earn a higher speed rating requires a stiffer casing, which affects harshness.

The F1 All-Season handles well on both dry and wet surfaces because of a couple of features in its "Ultra High-Performance Zone": aggressive tread blocks along the tire's shoulder and "TredLock Technology," a feature of the grooves between tread blocks which, when the tire is generating significant lateral acceleration, lock the blocks together to stiffen the tread. Image: Author.

Next I tried pushing the HHR hard on curvy roads. This subjective test was a bit different than the one at Daytona as it was done on dry surfaces. I noticed that, when on Goodyears, lateral grip was greater and the steering response was quite a bit better. The differences are because of the F1 AS's more aggressive tread, more performance-oriented rubber compound, stiffer Kevlar- and carbon fiber-reinforced casing and tread blocks which are larger. On the other hand, these differences were a bit exaggerated because the Goodyear, in-spite of being the same size as the Firestone (215/50ZR17) had a wider tread and the higher speed rating. Had the Firestone had the same tread width and speed rating, the difference would have been noticeable, but not as dramatic.

At the time this photo was taken, about a month after the HHR was delivered, the Firestone Firehawks' sidewalls were showing the reddish-brown typical of anti-ozonant and anti-oxidant rubber additives which are in "full bloom". Image: Author.

The last issue which came up in my subjective comparison of the Firestone Firehawk GT03 to the Goodyear Eagle F1 All Season was appearance. The HHR was less than a month old when I noticed the Firestones' sidewalls turning an ugly, reddish-brown. This happens to all tires to varying degree and is caused by atmospheric conditions acting on chemical components which make-up the rubber used in the sidewalls. In extreme cases, the results are unattractive, as shown in the picture of the Firestone taken about a month after the HHR was purchased. Since the Goodyears were acquired-at this writing, three months ago-there has been no color change. The reason the Goodyear Eagle F1 AS does not exhibit color change due to atmospheric effects is a chemical additive used in making it and a few of Goodyear's other, newest tire types. Called "PermaBlack", it's a proprietary material which preserves that "new-tire" appearance. All tire manufacturers use varying amounts of anti-ozonants and anti-oxidants to inhibit weathering and aging, however, those protective measures are focused on preserving the mechanical properties of the tire not its appearance. As the anti-ozonant and anti-oxidants begin to work, or "bloom" as tire engineers say, they cause the surface of the sidewalls to turn reddish-brown. The addition of PermaBlack stops the color change but still allows the anti-ozonants and anti-oxidants to work.

The bottom line on this new tire, so far: In two subjective tests, one in the wet, the other in the dry and one comparing the Michelin Pilot and the Bridgestone Potenza to the Goodyear F1 All Season and the other comparing the Firestone Firehawk to the new Goodyear, the Eagle F1 AS demonstrated noticeable advantages in dry and wet traction, wet acceleration and braking, dry and wet steering response, on-center steering feel and tread noise. Lastly, the Goodyear's sidewalls do not discolor.

This new tire is available now for many daily driver, passenger cars and will be available in the Fall of 07 in C5 non-Z sizes. Image: Author.

I think, with the new, Eagle F1 All Season, Goodyear has a winner...especially for owners of cars like Cadillac CTSes, Infiniti G35s, Pontiac Solstices and, of course, Chevy HHRs. As for the Corvette C5 sizes of the F1 AS? Well-based on testing the tire on a few of the vehicles just listed, the F1 All Season may be a darn good, non-EMT choice for C5s which are driven year-round. We'll know for sure, once I test this new tire on a Corvette this Fall. As soon as Goodyear makes a set in the C5 sizes available, I'll put a set of them on a Vette and begin testing. I'll update this tire review with information from that evaluation next Spring.