[carswaps]

My new R32 GTR has 19" alloys fitted:
Rears tyres are 235/35/ ZR19 - (19X9.5)
Fronts are 285/35/ZR19 - (19X8.5)

The car is new to me but will this tyre/wheel size cause any problems?
Its a tyre diameter difference of 5.14% - 82.25 front 99.75 rear
How much leeway does the Attessa system have?
At the moment i have no problems ...no 4WD light on etc but have read it COULD cause problems?
Any advice would be great
Cheers

 

[Adam Kindness]

from what I understand its more the rolling radius you need to watch. Differect sizes/aspect ratios may confuse the 4wd system. So with your different widths you will prob have a slight difference in circumference.

Different widths should be fine.

PS - I think you have the sizes mixed up above

 

[carswaps]

Err yeah...opps sorry:chuckle:
Rears are 285/35/ZR19 - (19X8.5)
Fronts tyres are 235/35/ ZR19 - (19X9.5)

 

[Adam Kindness]

or even

Rears are 285/35/ZR19 - (19X9.5)
Fronts tyres are 235/35/ ZR19 - (19X8.5)

 

[CSB]

is that an indicator in the front pic?!

4wd, I would choose all the tyres same size

 

[carswaps]

or even

Rears are 285/35/ZR19 - (19X9.5)
Fronts tyres are 235/35/ ZR19 - (19X8.5)

WTF i,m just too tired cheers mate !:bowdown1:

 

[carswaps]

is that an indicator in the front pic?!

Yeah they are clear with orange bulbs

 

[Cris]

Yeah they are clear with orange bulbs

Your's must be the only R32 GTR with side repeaters.

Are you sure your rear tyres/wheels are 9.5 and 285. I run 9.5" with 255s and they look about the same. I'd expect the bigger tyre to 'overhang' the rim more.

I'm not 100% sure but I'd guess that the 4WD system would be OK with a (slightly) larger rear tyre than front. Not sure I'd want to be the one to test the theory out though! Mind you if you're worried you could always run it in 2WD until you can get tyres with the same rolling radius.

 

[mava_rules]

not sure about how much difference in rollling radius there is in yours but i know when i had to stick a couple of tempary wheels on back of mine (55 profile instead of 50) i was advised to remain in rwd only (by pulling the fuse out) or it would destroy the attessa clutch very quickly.
your r/r may be very minimal though but dont know the equation to work it out.

 

[Cris]

The difference is easy 285-235 = 50mm then 35% (the aspect ratio) is 17.5mm bigger.

 

[chippy]

if you put a 285 30 19 on rear you would only have a 1% r/r difference that should be well within tolerance
thats 20.42mm bigger r/radius

 

[chippy]

An if you put 275 30 19 0n rear you would have a 0.08 % difference
thats 1.57mm bigger r/radius

 

[chippy]

at the moment with your tyre sizes there is a 5.41% difference which is 109.96mm r/radius bigger not good

 

[mava_rules]

didnt even notice it was same profiles on each, so yeah, would say it would cause problems. keep in rwd untill you get a different profile on rears.

 

[carswaps]

Which and where is the fuse i pull to make it RWD only?

 

[Nocturnal]

From what I understand, you will kill the transfer box fairly quickly as your 4WD system will be engaged all the time thinking one of the wheel is slipping.

The fuse is located under the dash on the driver side, the top left hand corner fuse labeled 4WD (10 amp), pull that fuse and it will disengage the 4WD system.

 

[mava_rules]

as above, only thing is it brings on the abs light too (never tried to see if abs was actually turned off aswel though) there is another fuse under the bonnet labled 4wd, says in the workshop manual to pull that one if using a 2 roller brake tester so may be a better option?

 

[LeoSR20]

keep to 17s or 18s and you will see the change in your car.i had 19s on mine and i wished i never bothered.