Tyre sizes - V50 18"

[sprout99]

Who had converted to a more popular size?

I was considering the 225/40/18

The OEM size is just silly - rare and really expensive

[Daim]

Okay... If you have the 215/45 R18 tyres, then your speedo should be updated. So if you take the 225/40 R18 (more popular and no worry at all on the 18"s), you'll need that speedo update removed...

No problem though what so ever

[scoobysn7x]

Originally Posted by Daim

Okay... If you have the 215/45 R18 tyres, then your speedo should be updated. So if you take the 225/40 R18 (more popular and no worry at all on the 18"s), you'll need that speedo update removed...

No problem though what so ever

I've seen a set of second hand 18"s I'm interested in the tyres are 225/40 R18, I'm currently running 205/50 R17's on my S40 will the 18's fit ok no rubbing etc, and the speedo being out will that bring an error on the dash or will it just put the speedo out a bit (happy to put up with the speedo being a bt out)

[Daim]

With 225/40 R18 you don't need a speedo recalibration, as it is within the Volvo specs (same tire diameter as a 17" rim).

Unless you are lowered beyond the limits, there won't be a problem with rubbing etc. Volvo does recommend to fit steering limiters, but in 99% of all cases, you won't experience anything like that (rubbing inside the wheel wells).

The speedo is nearly spot on. If you drive 215/45 R18 without an update, the speedo is bang on that, what you are driving. With 225/40 R18 it is a little out - like normal.

[sprout99]

our car is R design (not SE) but has the SE 18" Medusa's

original size should be 205/50/17 but was upgraded when new.

I'm more worried that the side wall will be much smaller on 225/40/18
and ruin ride.

235/40/18 is a perfect swap but not much cheaper - although they actually fit rims properly

( we fiited part worn of this size on rear at minute due to tyre prob and it looks really good)

[Daim]

The side wall is more larger on the 225/40.

(225/100)*40 = 101,25 mm
(215/100)*45 = 96,75 mm

So the 225 should be more comfortable...

235/40 R18 would be awkward, as they do tend to rub (even without any lowering).

[sprout99]

any pics of 225/40/18 tyres on medusa rims anyone?

[sprout99]

Originally Posted by Daim

The side wall is more larger on the 225/40.

(225/100)*40 = 101,25 mm
(215/100)*45 = 96,75 mm

So the 225 should be more comfortable...

235/40 R18 would be awkward, as they do tend to rub (even without any lowering).

(225/100)*40 = 90 mm

[Daim]

Originally Posted by sprout99

(225/100)*40 = 90 mm

Ah, you're right! I misstyped... Thought something was wrong...

But those 6 mm won't be noticed - and as these are just calculations and most tire manufacturers have different tolerances.

Again, those 6 mm won't be noticed at all...

As I went from 215/45 R18 to 225/35 R19, the loss in comfort was barely noticeable (really hard to say). As I tested a friends 225/40 R18 compared to my older 215/45 R18, I only noticed better traction and no difference in comfort...

[sprout99]

Originally Posted by Daim

Ah, you're right! I misstyped... Thought something was wrong...

But those 6 mm won't be noticed - and as these are just calculations and most tire manufacturers have different tolerances.

Again, those 6 mm won't be noticed at all...

As I went from 215/45 R18 to 225/35 R19, the loss in comfort was barely noticeable (really hard to say). As I tested a friends 225/40 R18 compared to my older 215/45 R18, I only noticed better traction and no difference in comfort...

225/40/18 is the obvious choice for me - popular size
hopefully they'll fit rims properly unlike the 215/45's

i want to go for uniroyal rainsport 2's at £90 a corner.
Really good tyre too