Slightly different tyre sizes

[Bighoose]

Fairly new to the forum and hope this is the right place for a couple of tyre question, sorry if not.

My current car runs with 225/45 17 W (factory) tyres, and I have a set of decent winter tyres in the shed from my last car, which are 205/50 R17 V. A quick Google brings forth some conflicting advice, so I'd be grateful for any pointers on whether it's advisable to have them fitted.

Secondly, I stored them in a bit of a hurry and they are stored "in position" (ie rollable, not on side) side by side in a good shed where the temperature doesn't get too extreme. But they've been in there for 2 years and I'm possibly over thinking things but wondering if I should have been rotating them a bit to avoid them getting misshaped. Does that happen?

As I said, grateful for any advice really.

[Bobupndown]

If the car had other tyre size options, eg. for different trim levels which are the same as your winters then I'd happily fit them. If not you'd need to check suitably and declare modifications to your insurer, you should probably declare the fitment of a different tyre size anyway?
As far as storage goes I can't imagine without the weight of a car sitting on the tyres that it will make the slightest bit of difference. I keep winter tyres which are on a spare set of alloys stacked on top of each other, only have them on a pallet so they're not directly sitting on the ground.

[samoht]

Personally I'd fit them and not think twice about it.

Rolling radius is very close - a 2.5mm difference which is less than the difference between a new and worn tyre.

It's narrower, but to my mind that's part of what makes it a more effective winter tyre.

The handling and roadholding will be less good, but probably still acceptable, and again that's the trade-off for winter tyres.

[Bighoose]

Thanks for the replies guys, I wasn't too worried about the wall height/aspect ratio, more about the width as it seems quite different. I can live with a small decline in handling as a trade off for better cold weather performance (I'm Scotland). Still not sure how I'd check that they definitely fit the rim (appreciate the advice to check about other factory but not sure what sites to use to check that. Do people think a 205 tyre will generally always fit on a rim that previously had a 225 on it? Or is it not that simple?

[Mr Tidy]

It depends how wide the rims are.

This might help:- https://www.tyresizecalculator.com/charts/tire-wid...

[samoht]

Sorry, that's a good point about the width of the wheels.

Yeah, a 225 can fit a range of rim widths, so depending where on the range your current wheels are will decide how comfortably the 205s will go on.

It's unlikely to be impossible to fit the 205 to your wheels, it's more a question of what your chosen tyre fitter will be happy to fit.

Extreme example of a 225/40 on 8.5" wide wheel:

[Bighoose]

Taking in board the advice about about wheel size I've found this site that has a lookup tool for rim sizes.

https://www.wheel-size.com

It says that for my car and OEM tyre the wheel size is 7.5Jx17 ET46

So I assume 7.5 is the width of the wheel.

The question now being can a 205/50 tyre fit to a 7.5 wheel.

Using the other site provided by MrTidy above it says that a 50 aspect on a 7.5 wheel won't work as a 205. So I think I now have my answers and they probably for or fit well.

I'll probably now do what I should have done with the last car and just buy all season tyres and be done with the swaps.

Thanks again I really do appreciate the help here.

[samoht]

I don't think the site above is definitive about it not fitting.

This suggests 7.5 is the widest rim that will 'fit' a 205/50
https://wheelssize.com/wheels/17x7.5/P-205-50r17/

so a bit on the limit of 'normal' fitment (getting towards 'stretched') but almost certainly fine.

[Matt_E_Mulsion]

If they are just tyres, ie not on rims then with regards to storage, they are stored standing up on racks when they are new.

[brillomaster]

every table i can find on t'internet suggests 205 will be fine on a 7.5" rim.

and as you say, difference in rolling circumference between a 225/45/R17 and a 205/50/R17 is less than half a percent.

So yes, it'll be absolutely fine. get them fitted.

[tapkaJohnD]

Bighoose,
No argument with the above, but how old are the spare tyres? The manufacturers, and the AA/RAC recommend that even unworn-out tyres more than seven years old should be replaced, as the rubber will have deteriorated.

JOhn

[Bighoose]

They are about 5 years old but have plenty of tread being only used lightly for 2 winters then stored. I was thinking of putting them on this winter and next and then scrapping them and going for an all season if I still have the car ( we have the Continental all seasons on my wifes Tuscon and they make some difference in snow and ice). That would pretty much work in with the current summer tyres being due for replacement given my milage.

I wouldn't go for winters again as the swapping over is a hassle and expense and all seasons are a sensible choice up here.

[Pica-Pica]

If they have had a reduced exposure to UV, they should be OK, subject to an inspection.