Tyres

[Kevin]

That's becuase it's not how the 5% rule works.

You take the ratio of the stock front tyres to stock rear tyres, ie the 'standard ratio'.

Then with whatever tyres you get, the ratio of the new tyres has to be within 5% of the ratio of the stock tyres, ie the 'new ratio' has to be within 5% of the 'standard ratio'.

[simonprelude]

Explained slightly better than me

That's becuase it's not how the 5% rule works.

You take the ratio of the stock front tyres to stock rear tyres, ie the 'standard ratio'.

Then with whatever tyres you get, the ratio of the new tyres has to be within 5% of the ratio of the stock tyres, ie the 'new ratio' has to be within 5% of the 'standard ratio'.

[Silver Surfer]

Good,

I'll get some wider 265 rear tyres then.

SS

[TheSebringOne]

Sorry Kevin, but without sounding a bit below the avearge IQ, then 215 45 16 (stock fronts) and 255 40 17 (upgraded rears) should be ok as SS stated? Thats on stock oems 94+ 16/17s combo.

[Silver Surfer]

That's becuase it's not how the 5% rule works.

You take the ratio of the stock front tyres to stock rear tyres, ie the 'standard ratio'.

Then with whatever tyres you get, the ratio of the new tyres has to be within 5% of the ratio of the stock tyres, ie the 'new ratio' has to be within 5% of the 'standard ratio'.

Just to be pedantic....do you mean 5% of the 5% (if the stock ratio is 5% for arguement sake)....ie +/-0.25% .

215/45/16 and 245/40/17 ratio is 4.67%
215/45/16 and 255/40/17 ratio is 6%
225/45/16 and 255/40/17 ratio is 4.43% (current)
225/45/16 and 265/40/17 ratio is 5.75% (?future)

As you can see, there is more than the 5% of the stock ratio (+/- 0.25%) change yet the cars are OK?!?

SS

[vic]

That's becuase it's not how the 5% rule works.

You take the ratio of the stock front tyres to stock rear tyres, ie the 'standard ratio'.

Then with whatever tyres you get, the ratio of the new tyres has to be within 5% of the ratio of the stock tyres, ie the 'new ratio' has to be within 5% of the 'standard ratio'.

hiya - wonder what is the significance of this 5% rule? How does it affect the abs/tcs and perhaps more importantly/interestingly why would it affect these systems if >5%?

cheers

v

[simonprelude]

If the ratio is greater than the 5% then this is outside of the allowed tolerance, ie the ECU will think that one set of wheels is spinning / skidding and cause the TCS to cut power.

[AR]

If the ratio is greater than the 5% then this is outside of the allowed tolerance, ie the ECU will think that one set of wheels is spinning / skidding and cause the TCS to cut power.

Ditto that is why I reckon that 215 40 17 and 255 40 17 are great sizes for the NSX.

[278kmh]

but the differenz of the circumference of
205-50-15 zu 225-50-16 ,is 7,75%

and the differenz of the circumference of
215/40 ZR 17 und 255/40 ZR 17 is 5,3 %

:think:

[Silver Surfer]

but the differenz of the circumference of
205-50-15 zu 225-50-16 ,is 7,75%

and the differenz of the circumference of
215/40 ZR 17 und 255/40 ZR 17 is 5,3 %

:think:

The 5% tolerance is between the front and rear tyres circumference (against each other).

SS