Bigger wheels tyres - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Stage A · 23rd September 2008, 11:28 PM

Am contemplating putting bigger alloys with 225 50 R17 tyres on the front and 235 50 R17's on the back. The standard ones are 205 55 R16's all round. I have never changed the tyre/wheel size before. So before I spend my money/damage the car has anyone done this before and am I making a mistake?

It is a Dayz RS4 with standard suspension.

RSVFOUR · 24th September 2008, 08:14 AM

As you have an AWD system it is very important that the rolling radiuses of the front and rear tyres are the same.
So 235 45 17 (or 235 40 18) will be fine as long as the FR & RR are this size ,.
Simarly you need to make sure you get wheels with the stagea offset (30-33)
GTR or GTS wont fit without spacers

vss irvine · 24th September 2008, 10:32 PM

i run 235/40/18 on the front (correct offset)with 15mm spacers to bring them right out to the arches, on the rear i have 245/40/18 with just 3mm spacers again correct offset.

RSVFOUR · 24th September 2008, 10:52 PM

vss
Theres not a lot of difference on the rolling radius of those two ( 1.24% as it happens) so that is within normal acceptable limits (its generally reckoned 2.5 % is the absolute maximum for awd or 4wd cars)
However the same is ideal.

23rd September 2008, 11:28 PM	#1 (permalink)
Stage A GTR Register Member Join Date: Sep 2008 Location: NW London Posts: 24	Bigger wheels tyres Am contemplating putting bigger alloys with 225 50 R17 tyres on the front and 235 50 R17's on the back. The standard ones are 205 55 R16's all round. I have never changed the tyre/wheel size before. So before I spend my money/damage the car has anyone done this before and am I making a mistake? It is a Dayz RS4 with standard suspension.

24th September 2008, 08:14 AM	#2 (permalink)
RSVFOUR GTROC Member Join Date: May 2006 Location: On the wall MAY 2008 Posts: 808	As you have an AWD system it is very important that the rolling radiuses of the front and rear tyres are the same. So 235 45 17 (or 235 40 18) will be fine as long as the FR & RR are this size ,. Simarly you need to make sure you get wheels with the stagea offset (30-33) GTR or GTS wont fit without spacers __________________ RSV Four FFC (Flying Fridge Carrier...... now with twin turbos)

24th September 2008, 10:52 PM	#4 (permalink)
RSVFOUR GTROC Member Join Date: May 2006 Location: On the wall MAY 2008 Posts: 808	vss Theres not a lot of difference on the rolling radius of those two ( 1.24% as it happens) so that is within normal acceptable limits (its generally reckoned 2.5 % is the absolute maximum for awd or 4wd cars) However the same is ideal. __________________ RSV Four FFC (Flying Fridge Carrier...... now with twin turbos)

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24th September 2008, 10:32 PM	#3 (permalink)
vss irvine GTR Register Member Join Date: Feb 2008 Location: ayrshire, scotland Posts: 13	i run 235/40/18 on the front (correct offset)with 15mm spacers to bring them right out to the arches, on the rear i have 245/40/18 with just 3mm spacers again correct offset.