[amw896]

Hey all,

I need some more input as 1010 tires are telling me its a no go.

I have a spare set of Falken Ziex' in mint condition that I would like to use for replacing my Pirelli run flats when the time comes.

Here are the numbers:
Stock
Front: 225/35/R19
Rear: 245/30/R19

Spare Falkens
Front: 225/40/R19
Rear: 255/35/R19

I'm showing a 5% variance for the rears and a 3.5% variance for the fronts. They also indicate risk of brake failure if I do this?...

[pikcachu]

Originally Posted by amw896

Hey all,

I need some more input as 1010 tires are telling me its a no go.

I have a spare set of Falken Ziex' in mint condition that I would like to use for replacing my Pirelli run flats when the time comes.

Here are the numbers:
Stock
Front: 225/35/R19
Rear: 245/30/R19

Spare Falkens
Front: 225/40/R19
Rear: 255/35/R19

I'm showing a 5% variance for the rears and a 3.5% variance for the fronts. They also indicate risk of brake failure if I do this?...

going over 1.5% is not recommended.... let alone 3% or 5%

[amw896]

Originally Posted by pikcachu

going over 1.5% is not recommended.... let alone 3% or 5%

I thought that was only in the case of awd.

[pikcachu]

Originally Posted by amw896

I thought that was only in the case of awd.

for awd i would say don't even do 1.5%...

The DSC uses the speed of both front and rear tires to calculate what to do so if you change the diameters than you will alter how the system behaves with most likely unintended consequences....

The car might think you are sliding and keep brakes on all the time on your rear if it sees too much variance in speed

[amw896]

Originally Posted by pikcachu

for awd i would say don't even do 1.5%...

The DSC uses the speed of both front and rear tires to calculate what to do so if you change the diameters than you will alter how the system behaves with most likely unintended consequences....

The car might think you are sliding and keep brakes on all the time on your rear if it sees too much variance in speed

Makes sense but then wouldn't the rolling diameters have to be the same between the stock 18" set up (F 225/40/r18 ; R 245/35r19) and the stock 19" set up (F 225/35/r19 ; R 245/30/r19)?

when I plugged in all four sizes into the calculator, I got different rolling diameter across all of em!

[pikcachu]

Originally Posted by amw896

Makes sense but then wouldn't the rolling diameters have to be the same between the stock 18" set up (F 225/40/r18 ; R 245/35r19) and the stock 19" set up (F 225/35/r19 ; R 245/30/r19)?

when I plugged in all four sizes into the calculator, I got different rolling diameter across all of em!

there is only 0.45% and 0.14% difference... which is way below 1.5%

[amw896]

Originally Posted by pikcachu

there is only 0.45% and 0.14% difference... which is way below 1.5%

ahh yep, good call! Thanks man, looks like I gotta sell these spares.