Rear tyre size - ZR-1 Net Registry Forums

max76 · 06-16-2017

Hi guys,
Here in Italy we (zr1 owners) have a problem with the rear size tyre.
We have an only brand who produce the 315/35/17 tyre.
Me and some other guys, zr1owners, want put on the rear the 335/35/17, it's a less rare tyre and wr can choose Michelin or Pirelli.
But we have an other problem, we need a "paper" where GM tell us that there are not technical problem using the bigger tyre (always on the original rim).
Someone of you know how I can contact GM for have this documents?
Thanks to everyone
Max

ssrszz4 · 06-16-2017

Amazon don't ship to Italy?

Sent from my XT1585 using ZR-1 Net Registry mobile app

XfireZ51 · 06-16-2017

Max,

I'm not sure an OEM would produce documentation on mounting anything but their recommended size tire.

Kevin · 06-17-2017

especially for a car that hasn't been produced since 95 and that gm seems to want to forget exists.

max76 · 06-17-2017

Hi guys,
Is not a problem of shipment...the problem is that here in Italy we cannot put on the car a different tyre misure if it's not written on the car technical paper named "libretto". But for this modify we need a technical relation by Gm...I hope that I explain correctly the problem...

efnfast · 06-17-2017

I would think getting that document from GM would be harder than getting our dyno sheets. GM won't put their name on it, unless it's been engineered and tested.

PhillipsLT5 · 06-17-2017

Tire rack or discount tire websites would show fitments

XfireZ51 · 06-17-2017

What Max is saying is that in Italy, no one will sell or mount tire sizes on his wheels that do not conform w OEM spec. So in order to do so, he needs the owners manual or some other official GM document showing that the 335s can be fitted to the OEM wheel and are sanctioned by GM.
I would be very surprised if anything like that exists.

G-Sting · 06-17-2017

Quote:

Originally Posted by efnfast

I would think getting that document from GM would be harder than getting our dyno sheets. GM won't put their name on it, unless it's been engineered and tested.

Someone here could make something up for our friends in Italy?

We've got talent, I'm sure.

cheers,
G

Ccmano · 06-17-2017

Agreed, no manufacturer will produce a "one off" letter like this. Not for a current production car let alone one that has been out of production for 22 yrs. Believe me I know. I've worked corporately for Mercedes, Hyundai and Mitsubishi.

If the OP wanted to sidestep the law in Italy, I offer this convoluted solution. Have the tires removed from the wheels in Italy, ship the wheels to a country where this is not an issue. Have tires mounted there and ship back. Or just buy wheels and tires elsewhere and ship in.

Of course this doesn't save any money as the OP wanted.

Isn't socialism a wonderful thing! You need government approval for everything. It's for your own protection.
H

06-16-2017	#1
max76 Join Date: Apr 2009 Location: ITALY Posts: 264	Rear tyre size Hi guys, Here in Italy we (zr1 owners) have a problem with the rear size tyre. We have an only brand who produce the 315/35/17 tyre. Me and some other guys, zr1owners, want put on the rear the 335/35/17, it's a less rare tyre and wr can choose Michelin or Pirelli. But we have an other problem, we need a "paper" where GM tell us that there are not technical problem using the bigger tyre (always on the original rim). Someone of you know how I can contact GM for have this documents? Thanks to everyone Max

06-16-2017	#2
ssrszz4 Join Date: Jan 2017 Location: US Posts: 233	Re: Rear tyre size Amazon don't ship to Italy? Sent from my XT1585 using ZR-1 Net Registry mobile app

06-16-2017	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,666	Re: Rear tyre size Max, I'm not sure an OEM would produce documentation on mounting anything but their recommended size tire. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

06-17-2017	#4
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,633	Re: Rear tyre size especially for a car that hasn't been produced since 95 and that gm seems to want to forget exists. __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

06-17-2017	#5
max76 Join Date: Apr 2009 Location: ITALY Posts: 264	Re: Rear tyre size Hi guys, Is not a problem of shipment...the problem is that here in Italy we cannot put on the car a different tyre misure if it's not written on the car technical paper named "libretto". But for this modify we need a technical relation by Gm...I hope that I explain correctly the problem...

06-17-2017	#6
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,255	Re: Rear tyre size I would think getting that document from GM would be harder than getting our dyno sheets. GM won't put their name on it, unless it's been engineered and tested.

06-17-2017	#7
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,450	Re: Rear tyre size Tire rack or discount tire websites would show fitments

06-17-2017	#8
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,666	Re: Rear tyre size What Max is saying is that in Italy, no one will sell or mount tire sizes on his wheels that do not conform w OEM spec. So in order to do so, he needs the owners manual or some other official GM document showing that the 335s can be fitted to the OEM wheel and are sanctioned by GM. I would be very surprised if anything like that exists. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX

06-17-2017	#10
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Rear tyre size Agreed, no manufacturer will produce a "one off" letter like this. Not for a current production car let alone one that has been out of production for 22 yrs. Believe me I know. I've worked corporately for Mercedes, Hyundai and Mitsubishi. If the OP wanted to sidestep the law in Italy, I offer this convoluted solution. Have the tires removed from the wheels in Italy, ship the wheels to a country where this is not an issue. Have tires mounted there and ship back. Or just buy wheels and tires elsewhere and ship in. Of course this doesn't save any money as the OP wanted. Isn't socialism a wonderful thing! You need government approval for everything. It's for your own protection. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.