Tire & Wheel Questions

[PaulV]

I am interested in replacing my Wheels & Tires on my 99 Vert. I am looking at Cray HAWK Chrome Wheels and Michelin Pilot Sport PS2 ZP tires. I would like to go one-up on the wheel sizes, 18"F and 19"R but I'm not sure on tire size? This is what I am seeing on the CAC and other Vette Forums and would like some feedback/discussion regarding my choice of wheel width and tire size, to include my choice of wheel.


Wheels
18X9.0 F
19X10.5 R

Tire Size
245/40/18F
285/35/19R

I appreciate any and all feedback.

Thanks,


PaulV

 

[Toms007]

Love the wheels. IIRC, the tires sizes are 285/35 x 19 back, 245/40 x 18 fronts.

 

[DrNavyRet]

Love the wheels. IIRC, the tires sizes are 285/35 x 19 back, 245/40 x 18 fronts.

My calculations show that there would be a 1.14" stagger or .14" over stock. What is that going to do to the speedometer readings, the odometer readings and any effect on the traction contraction or handling control?

 

[Toms007]

I'm not a tire professional, but I doubt .14 difference in Diameter will make that much difference in the speedometer reading. You could drop back to a 275/35 x 19 that would put you .1 smaller in diameter than the 275/40 x 18 that came on our cars.

Referring to the TC and handling, again, I doubt seriously that it would be affected. But I stand to be corrected.

 

[DrNavyRet]

I'm not a tire professional, but I doubt .14 difference in Diameter will make that much difference in the speedometer reading. You could drop back to a 275/35 x 19 that would put you .1 smaller in diameter than the 275/40 x 18 that came on our cars.

Referring to the TC and handling, again, I doubt seriously that it would be affected. But I stand to be corrected.

I have also seen some who advocate 275/35/18 front and 305/30/19; others substitute 265/35/18 for the front set. Similarly for 18/18 setups, there are a variety of sizes advocated. Most state their desire to fill the "tire opening." With all the electronic "stuff" in our cars, it would seem to me that without actually knowing what changes one makes when you change the GM engineered factors by stating that it couldn't be by much is not good enough (no disrespect intended). One would not consider getting their computer "retuned" after changing such simple bolt on engine mods , why not when one changes wheels and tires which could affect handling, unsprung weight, suspension, speeding tickets or going too slow in the fast lane tickets, etc. There must be somewhere (I haven't found it) a chart that shows tire change by manufacturer and wheel size change and effect on the above items.

 

[6 Shooter]

18's & 19's

Firestone Firehawk Wide Oval RFT: Firestone Firehawk Wideoval RFT | Firestone Complete Auto Care
> Fronts: P245/40R18
> Rears: P285/35R19

Cray Scorpion Chrome Wheels: Corvette Wheels by Cray Wheels
> WHEELS | TSW Alloy Wheels
> WHEELS | TSW Alloy Wheels

​

http://www.corvetteactioncenter.com...wheels-tires-going-18s-19s-2.html#post1032553

 

[Toms007]

Circumference difference of about 5/16 of and inch would result in 3 revolutions difference/mile or about 20 feet. Which is about .003 difference 20/5280. Which in my books is negligible in MPH difference. If my math is wrong please correct me.

You are correct in saying that it can be configured with a computer re-tune. I'll say it again, the difference between the 275/40 x 18 and the 285/35 x 19 is 1/10 in diameter. The tire will change more in diameter due to tire wear than that difference. With 10/32" tread depth (5/16") figuring you are going to replace tires @ 2/32 (at the wear bars) that's 3/8" difference in diameter (3/16" x 2) or .375". Nobody worries about retuning the computer as the tires wear.....Just saying.

 

[PaulV]

Firestone Firehawk Wide Oval RFT: Firestone Firehawk Wideoval RFT | Firestone Complete Auto Care
> Fronts: P245/40R18
> Rears: P285/35R19

Cray Scorpion Chrome Wheels: Corvette Wheels by Cray Wheels
> WHEELS | TSW Alloy Wheels
> WHEELS | TSW Alloy Wheels

​

http://www.corvetteactioncenter.com...wheels-tires-going-18s-19s-2.html#post1032553

Shooter,

Are you happy with your CRAY wheels? What are you running for width's Front & Rear? I'm hearing that CRAY wheels are very heavy and effect performance, do you agree? Also, how are the Firestone tires are you happy with them and why did you choose them over the Goodyear or Michelin?

And by-the-way, your VERT LOOKS AWESOME!

 

[PaulV]

Thanks for the great feedback. I have another question regarding the Michelin Tires, they make 2 RFT's, the PS2 ZP's and the A/S Plus ZP's. The PS2's are almost $1,700 for a 20,000 mile tire and the A/S Plus ZP's are about $1,100 for a 45,000 mile tire....what's up with that? Can anyone explain the difference in these two tires???

Thanks,


PaulV

 

[Huskerman]

I have just been grumbling about that very thing last week. The A/S has a tire wear rating of 500 vrs the 220 on the PS2's. The 220 is a summer softer compound tire for perormance applications. That means you can track it or run Auto X's and you will get less milage on them even if you just tour in them. They are both run flats. So performance tires cost more. There are no A/S tires available in the size I need for my Grand Sport. So my choice is really slim, only Goodyears or Bridgestone Potenzas and the Michelin's. Most are available in run flats or non run flats. Price on the Michelins's is around 2100 bucks........I called Michelin customer support but they said that at this time no A/S tires are slated to be in production for the Grand Sport in the near future..........Nuts!

I have a set of Nitto Invo non run flats on there now but tried to find them the other day on line and couldn't in the size for my GS.

 

[Toms007]

For your information, the A/S means All Season, which Huskerman eluded to. They are a harder compound, thus the mileage differences. I have the Michelin PS2 ZP A/S plus tires on my 2001 and think they are great. But I don't auto-x or race it. I also have the stock wheels and sized tires.

 

[SG Lou]

I replaced my stock size wheels and tires on my 04 with 04 Z06 size and i don't see a problem with the speedometer, just sayin!
Hated the run flats so I'm running General EXCLAIM UHP's and they are great. Too bad they discontinued the line.



Front Tires P265/40ZR-17
Rear Tires P295/35ZR-18
Front Wheel Size 17 x 9.5
Rear Wheel Size 18 x 10.5

 

[SG Lou]

I replaced my stock size wheels and tires on my 04 with 04 Z06 size and i don't see a problem with the speedometer, just sayin!
Hated the run flats so I'm running General EXCLAIM UHP's and they are great. Too bad they discontinued the line.



Front Tires P265/40ZR-17
Rear Tires P295/35ZR-18
Front Wheel Size 17 x 9.5
Rear Wheel Size 18 x 10.5

Oops. Sorry. Didn't notice you wanted to move up to 18 / 19's

 

[DrNavyRet]

Circumference difference of about 5/16 of and inch would result in 3 revolutions difference/mile or about 20 feet. Which is about .003 difference 20/5280. Which in my books is negligible in MPH difference. If my math is wrong please correct me.

You are correct in saying that it can be configured with a computer re-tune. I'll say it again, the difference between the 275/40 x 18 and the 285/35 x 19 is 1/10 in diameter. The tire will change more in diameter due to tire wear than that difference. With 10/32" tread depth (5/16") figuring you are going to replace tires @ 2/32 (at the wear bars) that's 3/8" difference in diameter (3/16" x 2) or .375". Nobody worries about retuning the computer as the tires wear.....Just saying.

I played with the numbers and you are absolutely correct. So I go over to Discount Tire Direct to look for what tires are available in that size only to find no Run Flats. Pirelli P Zero A/S, Continental EC DWS, and Michelin AS+ with prices of 892, 910, 1nd 1418 shipped. [BTW I'm looking for an A/S tire] Any recommendations? No Firestone was listed and none of my local Firestone dealers have them.

 

[sdderr]

I don't have an opinion on the wheels or sizing, but I can say the Michelin ZP's were a fantastic improvement over the original, stock Goodyears that were on my 04 Coupe. Noise was much less, ride was better and they're still runflats. I have the summer tires and they are very sticky. Since my Vette doesn't get a lot of miles per year, the wear was not an issue.

 

[DrNavyRet]

I don't have an opinion on the wheels or sizing, but I can say the Michelin ZP's were a fantastic improvement over the original, stock Goodyears that were on my 04 Coupe. Noise was much less, ride was better and they're still runflats. I have the summer tires and they are very sticky. Since my Vette doesn't get a lot of miles per year, the wear was not an issue.

I had the Michelin Summer tires on my M3 and when I switched to the A/S version (the "summer tires were gone in 12000 miles), there was a clear difference. Smoother ride, traction felt the same, etc. Now I did not track the car, but for general driving, they were great. If anybody out there has any experience with the tires I mentioned above on their Vette or other car, I would appreciate their take. Thanks.

 

[6 Shooter]

Paul - Thanks for the compliment, I've never had performance issues but don't race, ...

Shooter,

Are you happy with your CRAY wheels? What are you running for width's Front & Rear? I'm hearing that CRAY wheels are very heavy and effect performance, do you agree? Also, how are the Firestone tires are you happy with them and why did you choose them over the Goodyear or Michelin?

And by-the-way, your VERT LOOKS AWESOME!

...Badyear, Michelin and Firestone have all been worn out by my Vette, it'll never have Badyears on it again!

​

 

[PaulV]

Thanks to all for the great feedback, It looks like I will go with the Michelin Pilot Sport A/S Plus ZP tires with the Cray Hawk Chrome Wheels. As far as prices go Tirerack had the best price for the Tires, 1,174.00 before a $70 mail-in rebate. DD Mods has the wheels, although the chrome is not available yet, for 1,850.00, no shipping charge.

 

[DrNavyRet]

Thanks to all for the great feedback, It looks like I will go with the Michelin Pilot Sport A/S Plus ZP tires with the Cray Hawk Chrome Wheels. As far as prices go Tirerack had the best price for the Tires, 1,174.00 before a $70 mail-in rebate. DD Mods has the wheels, although the chrome is not available yet, for 1,850.00, no shipping charge.

Don't forget the cost of new TPMS, mounting, balancing as well as some who charge for new lug nuts.

 

[6 Shooter]

Sam did everything for $2k out the door...

​