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Discussion Starter #1
So I have a GT JTD with 17" multispokes (OEM).

Details are (I believe) 17 diameter; 7J width; 40.5 offset

So I will be staying with 17" rims, but what can I get away with in terms of the '7J' and the '40.5'

Say, for example, I get 17 7J 35, what will that mean (in layman's terms if possible-I have been reading guides online, but amn't really any the wiser), or for that matter '7.5J'

I should mention that I have fairly new 215/45/17 tyres and would like to keep these-am I bound to a particular rim measurement in this case?

Your help/advice appreciated.
 

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So I have a GT JTD with 17" multispokes (OEM).

Details are (I believe) 17 diameter; 7J width; 40.5 offset

So I will be staying with 17" rims, but what can I get away with in terms of the '7J' and the '40.5'

Say, for example, I get 17 7J 35, what will that mean (in layman's terms if possible-I have been reading guides online, but amn't really any the wiser
Changing to 35mm offset would move the wheel 4.5mm rurther out than 40.5mm offset.
 

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Discussion Starter #3
Thanks David.

So more risk of kerbing etc?

So could move from 7 to 7.5 width (would my tyres fit this size?), but only really if keeping the offset constant at 40.5?

Would it be advisable to be looking at 35 offset or should I stick with the offset of my existing wheels?
 

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If you wanted 7.5" wide, you would need to go to 35mm offset.
ie same width & offset as the 156/147 GTA.

You could still use 215/45R17 but they would obviously be more stretched n the rim which will mean more likelihood of the rim touching the kirb instead of the tyre.

You could also move to 225/45/17 (the GTA size).
 

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Discussion Starter #5 (Edited)
If you wanted 7.5" wide, you would need to go to 35mm offset.
ie same width & offset as the 156/147 GTA.
Of course, makes sense now :) .

You could still use 215/45R17 but they would obviously be more stretched n the rim which will mean more likelihood of the rim touching the kirb instead of the tyre.
Given that it was a collision with a kerb/pothole that is causing this search for alloys, I think I would be advised to stay with 7 width.

You could also move to 225/45/17 (the GTA size).
Cheers. That's a possibility alright.
 

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Discussion Starter #6
And....I have a feeling I already know the answer, but will the wheels from a Spider (new shape) fit a GT?

I think that the 159/Brera/Spider have a 110 PCD and I need a 98 PCD?
 

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And....I have a feeling I already know the answer, but will the wheels from a Spider (new shape) fit a GT?

I think that the 159/Brera/Spider have a 110 PCD and I need a 98 PCD?
Correct.
159/Brera/Spider wheels will not fit a 156/147/GT/GTV/Spider
 

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Discussion Starter #9
And another one-if I move from a 40.5 offset to a 35 offset, will I need to change bolts?
 

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No the bolts should be the same. The offset only affects the relationship between the centre line of the wheel rim and the mounting hub.
 

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Discussion Starter #11
Thanks-so safe enough to get offset 35 with width 7 and keep my existing 215/45/17 tyres by the sounds of it.

Any fellow GT owners with wheels with a 35 offset?
Any issues?
 

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You may need new bolts! I've just had my wheels refurbed & had a set of loan wheels on the car (GTV Phase 1 multihole alloys) They were 6.5j x 16 but 30.5mm offset. My wheels are 7j x 17 but 40.5mm offset. This meant that the outer face of the wheels was about 4.5mm closer to the outside edge of the car and this was enough for it to foul the nearside wheel arch liner, with correct size (205/55/16) tyres. I know my car is a 147 and not a GT and 205/55/16 tyres are just about the tallest overall tyre/wheel combo you can get and they aren't the same but the amount of space in there is limited!

I suppose the easiest way to check it out is to try some 5mm spacers with what you've got already and see how it goes. Could save you a lot of money in the long run!
 

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GTV uses a longer bolt than the GT, 156 and 147.
 

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Discussion Starter #14
I suppose the easiest way to check it out is to try some 5mm spacers with what you've got already and see how it goes. Could save you a lot of money in the long run!
Sounds like a good idea alright. I see that the offset difference in your case was 10mm whereas the max I would go is +/- 5mm on my existing offset, so maybe will be ok for me (tis all very marginal though if we are talking in terms of mms!).

I really appreciate all this advice-learning a lot here :thumbs:
 

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Sounds like a good idea alright. I see that the offset difference in your case was 10mm whereas the max I would go is +/- 5mm on my existing offset, so maybe will be ok for me (tis all very marginal though if we are talking in terms of mms!).

I really appreciate all this advice-learning a lot here :thumbs:
You're right but the wheels were 1/2 an inch narrower, so the face of the wheel was about 4.5 mm closer to the outside of the car. (1/2 an inch narrower wheel is 1/4 inch (or 6mm) each side in towards centre line of wheel, smaller offset puts centre line of wheel further out. Therefore net effect is wheels pushed 4.5mm further to outside of car.
 

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Discussion Starter #16
I see. I will more than likely stick with 7J though as my existing tyres would struggle to fit 7.5J and I've only just put them on.
 
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