245/40/18 Vs 245/45/18

[IOWNU]

Hey guys,

I have an r32 GTR, it currently has R34 GTR rims with 245/40/18 Bridgestones all round.

I've had some camber issues (now fixed) so the fronts were chewed on the inside.

Anyway, can I fit 245/45/18s to replace the 2 damaged tyres? Will this effect my AWD (as I'll still be running 2x 245/40/18s)

And finally assuming they are suitable should the 245/45/18s go on the back or front?

Thanks!

Ali.

[(OO)SKYLINE(OO)]

Hey guys,

I have an r32 GTR, it currently has R34 GTR rims with 245/40/18 Bridgestones all round.

I've had some camber issues (now fixed) so the fronts were chewed on the inside.

Anyway, can I fit 245/45/18s to replace the 2 damaged tyres? Will this effect my AWD (as I'll still be running 2x 245/40/18s)

And finally assuming they are suitable should the 245/45/18s go on the back or front?

Thanks!

Ali.

You can fit whatever size tyres you want...

Eg. you want 245/40/18s, the middle number, 40 has to be the same FRONT AND REAR.

Otherwise you f**k up your Centre Transfer Case.

I have got,

FRONT

235/45/17R

REAR

245/45/17R

1st mesurement is for the width of the tyre.

2nd mesurement is for the height of the tyre.

3rd mesurement is for the wheel size.

Edited March 24, 2008 by (00)SKYLINE(00)

[IOWNU]

You can fit whatever size tyres you want...

Eg. you want 245/40/18s, the middle number, 40 has to be the same FRONT AND REAR.

Otherwise you f**k up your Centre Transfer Case.

I have got,

FRONT

235/45/17R

REAR

245/45/17R

1st mesurement is for the width of the tyre.

2nd mesurement is for the height of the tyre.

3rd mesurement is for the wheel size.

lol cool.

So thats a no go for the 245/45/18 pair with a 245/40/18 pair.

Centre transfer case sounds expensive....

[nisskid]

not sure how much of a tolerance there is with the ATESSA system, but if i was u id be sticking with the same profile. the difference between a 45 and 40 profile for a 245 is a bit over 10mm, so theres a fair difference.

[nisskid]

You can fit whatever size tyres you want...

Eg. you want 245/40/18s, the middle number, 40 has to be the same FRONT AND REAR.

Otherwise you f**k up your Centre Transfer Case.

I have got,

FRONT

235/45/17R

REAR

245/45/17R

1st mesurement is for the width of the tyre.

2nd mesurement is for the height of the tyre.

3rd mesurement is for the wheel size.

yes and no, the profile is relative to the tread width (245/45 = 45% of 245). the thing that affects the AWD system is overall rolling diametre difference between front and rear. for example the difference of the rolling diametre of a 225/45 and 245/45 is almost as much as the difference in rolling diametre as a 245/40 and 245/45. so basically the profile value is not the only thing u have to look for to determine 2 matching tyres for the front and rear.

[(OO)SKYLINE(OO)]

lol cool.

So thats a no go for the 245/45/18 pair with a 245/40/18 pair.

Centre transfer case sounds expensive....

LOL! Yes please have matching / the right tyres for you GTR and yes Centre Transfer Case sounds expensive.

yes and no, the profile is relative to the tread width (245/45 = 45% of 245). the thing that affects the AWD system is overall rolling diametre difference between front and rear. for example the difference of the rolling diametre of a 225/45 and 245/45 is almost as much as the difference in rolling diametre as a 245/40 and 245/45. so basically the profile value is not the only thing u have to look for to determine 2 matching tyres for the front and rear.

Sure.

I was just making sure that IOWNU's tyre height is the same cuz another member did a similar thing and but put his Silvia S15 rims on his GTR and his drive train had problems of couse. LOL!

[nisskid]

haha fair enough, was just trying to clear it up for anyone that read it and misunderstood what u said.

[IOWNU]

Thanks for the input fellas.

[(OO)SKYLINE(OO)]

haha fair enough, was just trying to clear it up for anyone that read it and misunderstood what u said.

Thanks dude! Always up for learning whats right and wrong.

Thanks for the input fellas.

No probs!

[Beer Baron]

You can fit whatever size tyres you want...

Eg. you want 245/40/18s, the middle number, 40 has to be the same FRONT AND REAR.

Otherwise you f**k up your Centre Transfer Case.

I have got,

FRONT

235/45/17R

REAR

245/45/17R

1st mesurement is for the width of the tyre.

2nd mesurement is for the height of the tyre.

3rd mesurement is for the wheel size.

that is wrong. the middle number as you call it is the aspect ratio. it's a percentage of the width. so on it's own it means nothing. your fronts have a sidewall of 105.75 and your rears have a sidewall of 110.25 so you almost certainly have different overall diameter tyres front to rear. as for how much difference is too much, personally I have no idea, but for me any difference is undesirable so I just stick with the same size front and rear.

[nisskid]

that is wrong. the middle number as you call it is the aspect ratio. it's a percentage of the width. so on it's own it means nothing. your fronts have a sidewall of 105.75 and your rears have a sidewall of 110.25 so you almost certainly have different overall diameter tyres front to rear. as for how much difference is too much, personally I have no idea, but for me any difference is undesirable so I just stick with the same size front and rear.

yes and no, the profile is relative to the tread width (245/45 = 45% of 245). the thing that affects the AWD system is overall rolling diametre difference between front and rear. for example the difference of the rolling diametre of a 225/45 and 245/45 is almost as much as the difference in rolling diametre as a 245/40 and 245/45. so basically the profile value is not the only thing u have to look for to determine 2 matching tyres for the front and rear.

[Beer Baron]

sorry. serves me right for not reading the whole thread properly. bad beer baron.

[ZENNON]

i was gonna say something but looks like you 2 have it covered

[ZENNON]

on a side note: old guy at work who brought his 4-door awd skyline over from NZ when he moved over had alot of problems when he changed tyres

(from memory he bought new tyres for front when back were still old or something) and it screwed it up totally so yeah - tolerances might be small!!

[godzl1975]

dont know if the question was answered prob was didnt read all of the posts ...having the larger rolling diameter wheel on the rears shouldnt affect the ATTESA as to having opposite way.

[R.3.2.G.T.R]

on similar note, my 32R currently has 255/40/17 on rear (nankang) and 245/45/17 on front (contisport).. so my rolling diameter is 102 rear vs 110.25 front.. not good at all.. would like to know if my car symptoms is due to this and attesa..

speedo needle is constantly bouncing (original broken cables replaced with 2nd hand item)

car tends to pull left/right at will randomly without turning steering (no steering wheel shudder even under braking and car does not pull left/right if checking for alignment etc)

does this sounds like attesa having issues due to different rolling diameters..

[nisskid]

on similar note, my 32R currently has 255/40/17 on rear (nankang) and 245/45/17 on front (contisport).. so my rolling diameter is 102 rear vs 110.25 front.. not good at all.. would like to know if my car symptoms is due to this and attesa..

speedo needle is constantly bouncing (original broken cables replaced with 2nd hand item)

car tends to pull left/right at will randomly without turning steering (no steering wheel shudder even under braking and car does not pull left/right if checking for alignment etc)

does this sounds like attesa having issues due to different rolling diameters..

nope. sounds like other issues.