Octavia 3.5, will 235/45/18 tyres fit?

[Seafar99]

Does anybody know if 235/45/18 tyres fit on a 18" alloy wheel 8j width with an offset of 35.

 

19 " would look great but I like my comfort on the suspension more. 

These alloys would poke out 22mm more and extend the circumference by 15mm are

There likely to be rubbing issues, anybody got any input? 

[SurreyJohn]

Don't know what an Octavia 3.5 is

 

For Mk 3 the 18inch sizes were 225/40 on 7.5J with ET51

or scout (with raised clearance) used 225/45 on 7.5J with ET46

 

For mk4 the 18 inch is 225/45 on 7.5J with ET45

 

I think you would struggle to get snow chains on 235/45 R18 without rubbing

 

There are plenty of wheels for Octavia III (3) and IV (4)

https://www.skoda.co.uk/_doc/639a0118-4da5-446b-a786-86e1f789b57b

 

 

[Ootohere]

?
Is the OP fitting Snow Chains?

 

http://briskoda.net/forums/topic/511761-octavia-vrs-mkiii-tyre-size-225-235

 

Edited 15 April, 2023 by toot

[PetrolDave]

1 hour ago, SurreyJohn said:

Don't know what an Octavia 3.5 is

Octavia 3.5 is commonly used when referring to an Octavia 3 facelift (FL).

[Seafar99]

Yes car is the face lift mk3. 5

Not planning to fit snow chains. 

Fairly sure 8j x 18 wheels are easily accommodated 

It's just the 235/45 side wall which may cause issues? 

[PetrolDave]

6 minutes ago, Seafar99 said:

It's just the 235/45 side wall which may cause issues? 

Why not compare the OE size tyres/wheels against your proposed size using a tyre calculator to see what the increase in diameter is (the rule of thumb is no more than 2% either way) and what the offset of the wheels will do to how far in/out the tyre is?

 

An example: https://tiresize.com/tyre-size-calculator/

[KenONeill]

2 hours ago, SurreyJohn said:

I think you would struggle to get snow chains on 235/45 R18 without rubbing

You may well be right, but the OP never mentioned and probably doesn't need chains.

[Carlston]

10 hours ago, Seafar99 said:

Does anybody know if 235/45/18 tyres fit on a 18" alloy wheel 8j width with an offset of 35.

 

19 " would look great but I like my comfort on the suspension more. 

These alloys would poke out 22mm more and extend the circumference by 15mm are

There likely to be rubbing issues, anybody got any input? 

 

There was an Octavia VRS for sale, that had 235/40R19 instead of the standard 225/35R19 fitted to its 7.5Jx19 ET51 X-TREM rims. That's a very large 4.8% increase in outside diameter, and a 15.25mm increase in radius.

 

Now. according to ETRTO, 235/40R19 needs at least an 8J rim width as shown below.

 

ETRTO approved rim widths

235/40 8.0-8.5-9.5

 

However, ETRTO often tends to group different tyre sizes together making for sometimes illogical approved rim widths, especially illogical minimum rim widths which is where some owners who fit wider tyres to their standard rims will fall foul. It doesn't help when ETRTO's approved minimum rim widths can sometimes be shown to be illogical because of the way they have grouped tyre sizes together.

 

As you can see in the chart below, 235/40R19 fits exactly in the middle of 225/35R19 and 245/45R19, and because these two tyre sizes both have 7.5-8.0-9.0 approved rim widths, it makes sense for 235/40R19 to also have these approved rim widths.

 

ETRTO approved rim widths

225/35R19 7.5-8.0-9.0

235/40R19 8.0-8.5-9.5 (logically, it would be 7.5-8.0-9.0)
245/45R19 7.5-8.0-9.0

 

The 8.0-8.5-9.5 that ETRTO has approved for the 235/40R19 tyre size really only makes sense on the lower profile 235/35R19 tyre size, and not the 235/40R19 tyres size as shown below.

 

ETRTO approved rim widths

235/35R19 8.0-8.5-9.5

 

Edited 15 April, 2023 by Carlston