225/40/18 or 245/40/18

[Brimma]

Is anyone currently running 245/40/18 tyres on their Mk2 Octavia ?

I've got 225/40/18 on my 18 x 8 Pro Race 1.2s, but Audi recommend 245/40/18 on the 18 x 8 Audi Calitos

Does anyone know any reason why the 225s can't go on the Audis ?

[Guest westallc]

they prob only put the wider tyre on to fill the arches abit better thats all the 225's will fit fine

[devonutopia]

Perhaps the Calitos has bigger arches? I've not heard of anyone trying anything other than 225/40s on 18s on octavia platform

[magic62]

Hi Bryan

The 245/40 have a much bigger circumfence as the 225/40. The Calito is a wheel for the Audi A6 and this cars rolls on a bit bigger circumfence as the Golf V plattform modells.

If a 225/50 18 would probably fit on the A6.

Grts

Mike

Edited 28 March, 2010 by magic62

[Nick P]

You want to use 225s on them. They're only 8Js. Skoda B14s came with 225s and they're 8J. The 245 recommendation is for when they're used on the A6.

[Brimma]

Cheers guys

Mike - quick question - why would a 245 be a bigger circumference to the 225 ? Surely only the tyre width is different ?

Or am I being a complete numpty ?

[Nick P]

There is a relationship between the height of the sidewall and the amount of stretch. The narrower the tyre on any given rim, the more pulled out diagonally the bead is relative to the edge of the tread.

Try and visualise what would happen with extremes of tyre width.

[Nick P]

Try http://www.1010tires.com/TireSizeCalculator.asp with 225/40/r18 and 245/40/r18 to see the difference...

[vRSLen]

Aspect ratio Bri

[Brimma]

[PowerMalc]

Cheers guys

Mike - quick question - why would a 245 be a bigger circumference to the 225 ? Surely only the tyre width is different ?

Or am I being a complete numpty ?

The profile number /40 is 40% of the width so on a 225 its 90mm while on a 245 its 98mm. (distance from the wheel rim to the outside of the tyre)

So the 245 has a bigger diameter and so greater circumference

IIRC a 205/55 x 16 a 225/45 x 17 a 225/40 x 18 all have virtually the same diameter/circumference

[Hedge]

235x40x18's would be a good fit Bry.

The problem with the 225's is that its a bit of a stretch on 8's/ It also depends on the manufacturer.

[Nick P]

The problem with the 225's is that its a bit of a stretch on 8's/ It also depends on the manufacturer.

Really disagree about that.

I have 225s on 8Js. It's an approved combo by the tyre manufacturers (Falken approve their 225s from 7J to 8.5J) and with both my Michelins and Vredesteins, the rim protector easily protects the rim.

Edited 28 March, 2010 by wega3k

[Brimma]

235x40x18's would be a good fit Bry.

That then would put my speedo/mileometer out of kilter

The 225/40 Ultrac Sessantas seem OK on the Pro Races, and there's still a fair bit of trad left, so I'll probably just have them transferred across to the Audis.

On another note, I'll have to keep the Audi badges on, as they are a different diameter to the Skoda's, so all I'll need then will be a part with a Seat logo and I'll have the full VAG set

[Nick P]

Nobody wants a Seat logo on their car Bry. :no: You'd be better off with something Lambo, Bentley or Bugatti.

[Brimma]

Nobody wants a Seat logo on their car Bry. :no: You'd be better off with something Lambo, Bentley or Bugatti.

It was a joke Nick - I'll stick with Skoda, VW and Audi

[dan_the_v8man]

Thats what i Did, funnily enough in that order too

[magic62]

That then would put my speedo/mileometer out of kilter

The 225/40 Ultrac Sessantas seem OK on the Pro Races, and there's still a fair bit of trad left, so I'll probably just have them transferred across to the Audis.

On another note, I'll have to keep the Audi badges on, as they are a different diameter to the Skoda's, so all I'll need then will be a part with a Seat logo and I'll have the full VAG set

Hi Bryan

other question has already been solved .

But you could put 215/40 18 on, this would give you a bit shorter gearing but at the downside the comfort will be worse. As the sidewalls will be even smaller.

As for the VAG set, you still forgot some badges. Bentley, Lamborghini are also part of the group

Cheers

Mike

[mannyo]

245s will rub the front suspension, I had 235s on a 18x8 with no problem. The 235/40 tyre will introduce a small speedo error, I prefered the 225s though.

[ckracer76]

My father has a 60-plate VW Eos with 18" wheels with factory fitted 235/40/18 Continental tyres. The Eos is the same platform as the Octavia right? Will his alloys be the same width as ours?

[ckracer76]

That then would put my speedo/mileometer out of kilter

Not according to this tyre calculator?http://www.etyres.co.uk/tyre-size-calculator

225 to 235 is only an increase of 1.26% or 8mm

[JohnMcL7]

Just in case you're not aware, this is a three year old topic.

I asked a similar question recently as my Octavia had 235/45R17 tyres (I have the stock 17in alloys) fitted by the previous owner whereas tyre sites said it was a 225/45/R17 size that was the normal one. Someone mentioned that some of the equivalent VW's also used the 235 width, I decided just to change to the 225 tyre when I replaced them as there didn't seem any particular advantage to the wider tyre.

John

[Brimma]

It is indeed three years old, and I don't think I have those wheels any longer, so I'll close this one down