Appropriate tyre size

makeorbrake

I have an old Astra that I need to bring to the scrappers - but the tyres on it are all brand new. I can't remember off hand but I think they were either one size greater or lesser than another car I wanted to put them on. ie. I think they are R14 - with the other car (a honda civic) either R12 or R15 currently.
Does the Civic have to have the same size wheels/tyres fitted - or could I just swap the whole set around??

sundodger5

if the difference in the size is the last numbers on the tyre e.g 195/65r 15
then no as this is the wheel size.
google is your friend on this

colm_mcm

make sure the pcd (distance between the bolts) and the centre bore (the size of the hole in the missle of the wheel where the hub comes through) and the offset (how far the wheels stick out over the arches) are suitable.

makeorbrake

Thanks for posting guys.

I came across a guide online (see below) for alloy wheel fitment - these are not alloys but I guess the principal is the same. There are slight differences. Are they close enough for this to work?

Astra/Kadet(84 to 98)
P.C.D.: 4x100
Offset: 35 to 45
C/Bore: 56.6

Civic (>91)
P.C.D.: 4x100
Offset: 35...38
C/Bore: 56.0

sundodger5

Based on that info i would say maybe. the C/Bore is an issue as you will need adaptors to make the wheels sit on properly otherwise the bolts are taking the weight of the car.
also we still havent established if the actual size of tyre wheel assembly is suitable. can you post all the numbers from the side of both sets of tyres?

makeorbrake

sundodger5 wrote: »

also we still havent established if the actual size of tyre wheel assembly is suitable. can you post all the numbers from the side of both sets of tyres?

The civic has the following right now;
185/60 R14 82H

Will post the numbers for astra tyres shortly.

makeorbrake

sundodger5 wrote: »

Based on that info i would say maybe. the C/Bore is an issue as you will need adaptors to make the wheels sit on properly otherwise the bolts are taking the weight of the car.

where can I get these adaptors?

These are the tyres currently on the Astra;

175/70 R13 82T

sentient_6

Not sure if this would be a help or not:

http://www.miata.net/garage/tirecalc.html

If you put in the two tire sizes you mentioned i think its saying there basically the exact same in terms of overall diameter etc.

sundodger5

a 185/60 14 is a direct replacement for 175/70 13. it would usually be done the other way (when a 14" was a big wheel) when fitting alloys.

makeorbrake

sundodger5 wrote: »

a 185/60 14 is a direct replacement for 175/70 13. it would usually be done the other way (when a 14" was a big wheel) when fitting alloys.

So I won't need adaptors -and I can be confident that the bolts wont be taking the weight of the car?

sundodger5

No just that the tyre size is interchangable. This means that ground clearence speedo accuracy and gearing will remain unaffected.
The other stuff still needs to be checked.

makeorbrake

sundodger5 wrote: »

No just that the tyre size is interchangable. This means that ground clearence speedo accuracy and gearing will remain unaffected.
The other stuff still needs to be checked.

Thanks. I guess i'm a bit concerned - as I want to give someone else the benefit of the set of tyres before I scrap my car but don't want them end up with a wheel coming off!:D
Where do I get these adapters and how can I walk away from the job satisfied that the bolts are not taking the weight of the car?

sundodger5

normally when you buy a set of wheels you get the adaptors and wheel nuts with them.
Some wheels would be able to fit more than one car and so would have a number of different adaptors in the box.
You may find a kind autofactor who would dig out the right ones for you.
Sorry i dont know more.

makeorbrake

@sundodger5: Thanks for your help. I have decided not to bother swapping them out with the Civic - just in case I have not done it correctly and theres a problem.

I scrapped the car yesterday and took the wheels home. I guess I will advertise them - and try and get a few yoyo back.

Will these fit on any Opel Astra?