Skoda Octavia III tyres

[Maggie1]

Hello,

 

I got an Octavia few months ago with 18inch alloys. Tyres were very slippy 225/35r18 recently I've ordered 245/50r18. Did anyone buy this size before ? I'm scared that they might not fit now and I've just wasted money. Please advise if anyone had 245/50r18 on Octavia 

[daftbugga]

Hi Maggie, welcome to the forum.

I can't answer your question directly I have R17's on mine but if you look @ owner's manual it should state the tyre sizes needed. In the absence of owners manual you may well find a sticker on the inside of the fuel filler flap, either will show tyre sizes needed, there is sometimes 2 shown 1 of them being an alternative.

In case you don't know the first figure IE 225/245 or other is the width of the tyre in mm's. The second figure IE 35/50 or other refers to the profile, the  height of the sidewall is shown as a percentage of the width so 35 will be 35 percent of 225.

The final figure starts with an R followed by in your case 18, that's the rim diameter in inches.

 

R18, no problem width & profile (sidewall) might be a problem as in replacement is too wide or profile too high.

It could also be the tyres being replaced were the wrong width/profile.

 

I'm surprised that 225/35 were Slippy.  

[OldAndyMac]

You don't say which Octavia you have but I don't think it matters. What matters is that these are critical safety items, you really need to be putting the correct size on for the wheels and space available (or at least very close). Plus, any difference in size will also effect your speedo. The standard size for the 18" wheel is 225/40/18 so the original tyres were off to start with, but what you have purchased is way off and I don't think they will even fit without rubbing. I would be cancelling my order sharpish and order the correct size. 

 

Look at the image below and you can see how much bigger the tyre is that you have just purchased, and your speedo will over-read a lot. Why did you purchase such a large tyre? if you are after more grip then really the only way to get that is to buy a better, high performance tyre like PS4's or Goodyear F1's

 

[KenONeill]

4 hours ago, Maggie1 said:

Please advise if anyone had 245/50r18 on Octavia

As the other 2 already said, you want 225/40/18, so you appear to have gone from "too small" (make not specified so I'll assume YingTong Ditchfinder or similar from the description "very slippy") to an also make unspecified "too large". If we're to actually help you beyond straight talking on size, we do need actual tyre make and model data.

[GaryL]

You need to go back to basics and find out what wheels/tyres are listed in the type-approval for your car.  You might not personally be that interested in "approved", but your insurance company may well be.

 

This link will give you access to the relevant data for all Skoda models:

https://www.skoda-auto.de/service/serienbereifung

 

Click on the green button labelled "Herunterladen".  This will give you a PDF of some 436 pages.  To find the section for your car, use the contents listing.

• Yours will be in a section labelled "Octavia III (5E)"
• Look for the page that matches the type-approval number in your registration document (eg mine is "e8*2007/46*0318*02", so I need to go to page 259)
• Look on that page for the block labelled with the engine code and variant from your registration document, (eg mine are DKZA and ACDKZAX0)
• Find the row that matches your wheel size. If your 18's were factory fitted, they will be 7.5Jx18

As the others have said, you will probably find the right size is 225/40R18

 

 

[Carlston]

9 hours ago, GaryL said:

You need to go back to basics and find out what wheels/tyres are listed in the type-approval for your car. You might not personally be that interested in "approved", but your insurance company may well be.

 

Many people buy secondhand cars and won't know if their car has a slightly different tyre size to what is approved. If your advice is taken to the logical conclusion then maybe half the cars on the road aren't insured due to a slight discrepancy.

 

Fortunately, UK insurance companies are governed by the UK courts, and I think you will find that a modification that doesn't make a material difference to the risk can't be used as a get out clause by the insurance companies...or they would all be doing it.

 

Even in the same size, tyres vary enormously in their performance. It wasn't long ago that UK insurance companies were expecting drivers to use summer tyres in the snow (even though that increases the risk of an accident) or if drivers used the most suitable winter tyres in the snow they faced an increase in their insurance premiums because the UK insurance industry unilaterally decided that using winter tyres in the winter was a modification. However, the UK courts soon put the UK insurance industry in their place when they found out about what they had been doing.

 

It's about time a law was passed that banned insurance companies from interfering in drivers' choice of tyres because they simply don't have the expertise to make rational decisions on the subject, as was shown by the summer/winter tyres fiasco.

 

Edited 13 September, 2022 by Carlston

[Stoofa]

Using "incorrect sized tyres" is always going to have the potential to increase risk, why wouldn't it?

The wheel manufacturer will say what size tyres the wheel was designed for, using anything "out of specification" is not using the item in accordance of the manufacturers recommendations - not going to take long for an insurance company to get out of claims there.

I also believe you are vastly over-estimating just how many people have incorrect sized tyres on their car - there is a certain demographic who will mess about in this area, but the vast majority will either not care (they bought the car as new or from a reputable dealer and continue to have the same size tyre fitted when required) or do care (in which case they will make sure the tyres are the correct size and are the brand the owner wants).

 

Insurance is not interfering with the drivers choice of tyre - they are interfering where incorrect parts are fitted to a vehicle and so they should be.

[Carlston]

1 hour ago, Stoofa said:

The wheel manufacturer will say what size tyres the wheel was designed for, using anything "out of specification" is not using the item in accordance of the manufacturers recommendations - not going to take long for an insurance company to get out of claims there.

 

ETRTO decides what range of rim widths each tyre size can be fitted to, not the wheel manufacturer.

 

The wheel manufacturer simply follows ETRTO's guidelines.

 

No one is suggesting fitting a tyre to a rim that ETRTO hasn't approved of. After all, ETRTO are the industry experts when it comes to tyre and rim sizes. Even top tyre brands such as Michelin follow ETRTO's advice.

 

Edited 15 September, 2022 by Carlston

[OldAndyMac]

although all relevant, i think the main point here is that I don't think that tyre will physically fit under the arches, especially the fronts on full lock.

[nickytheshaft]

On 13/09/2022 at 02:18, OldAndyMac said:

You don't say which Octavia you have but I don't think it matters. What matters is that these are critical safety items, you really need to be putting the correct size on for the wheels and space available (or at least very close). Plus, any difference in size will also effect your speedo. The standard size for the 18" wheel is 225/40/18 so the original tyres were off to start with, but what you have purchased is way off and I don't think they will even fit without rubbing. I would be cancelling my order sharpish and order the correct size. 

 

Look at the image below and you can see how much bigger the tyre is that you have just purchased, and your speedo will over-read a lot. Why did you purchase such a large tyre? if you are after more grip then really the only way to get that is to buy a better, high performance tyre like PS4's or Goodyear F1's

 

 

I totally agree, the speedo will be off and the tyres may not fit under the arch..;