OEM Tires


PHXGT

GT Owner
Mark II Lifetime
Sep 11, 2005
369
Phoenix, AZ
I didn't know if the following information was on the Forum or not. So, I thought I'd post.

At the Detroit Rally, I cornered Mark McGowan (of 212 MPH @ Nardo fame) and asked him some questions about our tires. Here are his conclusions. All the major tire manufacturers submitted multiple tires to be considered. The two finalist were Michelin and Goodyear. Goodyear was chosen because they agreed to work closely with the team and develop the perfect tire for the GT. I asked about going to wider tires, larger wheels and tires, etc. for both the front and back. He said that all the different sizes were tested and the OEM tires were the very best to work with the vehicle's drag, down force, weight, aero set up, etc. Mark said that the internal construction of the tire is more important than the width or profile. Our tires have been specially constructed by Goodyear for our cars.

Today, I got a mirror and a flashlight and recorded the DOT and CPER information off of the inside of the side walls for our tires (at least the MY 2005s). Here is all the information for our tires:

Goodyear F-1 Supercar

Front:
P235/45 ZR-18 (88Y)*
DOT M6X6 CPER 1805

Rear:
P315/40 ZR-19 (103Y)*
DOT M6Y5 CPER 2005

* The parentheses are important. They indicate greater than 186 mph.

Mark said that it is the DOT information to use to make sure you get the exact same tire. It represents the construction information submitted to the Dept. of Transportation.

Hope this is helpfull.
 
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Good Information

Thanks for posting this information; it will be very useful for all as the time approaches to replace tires.
 
They are pretty damn good tires, but I'll replace them with Michelin PS2's when the time comes if they come in the right sizes. I haven't even checked.
 
Scratch that. I just checked, and Michelin doesn't make those sizes. I think I'll stick with Goodyear! ;)
 
You know, when Motor Trend tested all the cars together (June '06), they "shod" all the cars in new Michelin PS2's, so they must exist, just not available yet or to the general public.
 
Turbo Joe's Hoosiers looked pretty good for those who don't drive in the wet.
 
fjpikul said:
You know, when Motor Trend tested all the cars together (June '06), they "shod" all the cars in new Michelin PS2's, so they must exist, just not available yet or to the general public.


Hmmm, that's interesting!
 
The tires Motor trend made available were an odd size, we didn't use them.
 
Ah, so that answers that question. Are you telling me Motor Trend was innaccurate in their reporting (ha,ha)? Glad to finally have that figured out. Thanks Cuda
 
Tires

I have tracked the GT on stock tires and IMHO they are the "weakest link" in the whole equation. A very knowledgeable individual high up the GT food chain told me that the reason the Goodyear’s were chosen was on price. IE Cost to Ford. Goodyear about gave them the tires. This was obviously a business decision. The tires are not bad for the street - but don't extract the full handling capabilities of this magnificent car that Tom Rickenbach and the chassis/suspension team worked so hard on developing.

I am having a set of Pirellis (of the Maserati MC12 variety) mounted next week and will report after some road and track use.

Gordon.
 
Is there still no sign of these Good Year street slicks?? http://www.racegoodyear.com/pdf/2006_price_book/showroom_dot.pdf
 
FB GT40 said:
...I am having a set of Pirellis (of the Maserati MC12 variety) mounted next week and will report after some road and track use...
Gordon, looking forward to the report. Sizes, pricing, availability, performace, etc. Would be nice to have more options.
 
Be very very carefull with stickier tires. Every single pebble on the road will be tossed into your paint by track tires. How sticky these street hoosiers are I do not know, but I know the ones I used 5 years ago did this. When you go racing some people will often put duct tape (colored) on the paint to protect it.
 
MDT said:
Be very very carefull with stickier tires. Every single pebble on the road will be tossed into your paint by track tires. How sticky these street hoosiers are I do not know, but I know the ones I used 5 years ago did this. When you go racing some people will often put duct tape (colored) on the paint to protect it.

Good point. I just bought some black duct tape today in preparation for an upcoming track day at Watkins Glen :thumbsup
 
I was thinking the same thing Punch. Wouldn't it be better to put a layer of blue painter's first followed by duct?
 
fjpikul said:
I was thinking the same thing Punch. Wouldn't it be better to put a layer of blue painter's first followed by duct?

This is exactly what I do. Blue tape first since it pulls off easy and duct tape next because it doesn't tear or puncture as easy. Best of both.
 
centerpunch said:
You DON'T want to use duct tape, it's WAY too sticky!

You want the blue painter's tape, designed to come off without hurting finish.

I always put a fresh coat of wax in the areas where the duct tape is going plus apply the duct tape semi-wet like vinyl. So far I've never pulled the paint off any of the street or race cars. But I agree painter's tape is a safer and easier alternative. I'll give it a try :thumbsup
 
Tires

Bob Woodman delivered my wheels with new Perellis this morning. Wheels looks good. Fronts a bit skinny, rears - just right. I'll install this weekend so look for a report next week. Bob also delivered a set of Hoosier DOT "slicks" - wow!These look full race to me. Report later.

G.
 
Very informative thread. The point with all these race tires is they all have a very short life. They loose their stick in a matter of months. I have brand new tires in the wrappers that are hard as rocks, ok for some touring but useless on the track. Then there is the issue of how many heat cycles they can go through.

I agree that the Goodyear tire is not the answer for the track, or on the edge performance.

I would hope that Baron could comment on tires and track set up, I know from a little birdie (that visits GT Joey :thumbsup :biggrin ) that Dave has some worthwhile data to share.
 
FB GT40 said:
I have tracked the GT on stock tires and IMHO they are the "weakest link" in the whole equation.

I am having a set of Pirellis (of the Maserati MC12 variety) mounted next week and will report after some road and track use.

Gordon.

G,
that sounds interesting ! Let us know how things go. Maybe you can track in OEM tires, and then in the Pirellis, and share the different lap times.. To get some measure in this discussion.

Stefan

PS: Finally back in operation. God, I am sooo disappointed I couldn't make it to the Rally, just because of some employee messing up my plans.... ; ((