Just got hold of two sets of 997 Carerra Fronts in 8x18 to go on my Octy

The origianal tyre size is 225/40/18 but i was wondering if 235/40/18 would be better as a standard carerra front wheel looks like the tyre does quite stretch over the wheel enough and i wanted them to stick out from the alloy a bit to protect it!

Anyway running 18's and got any ideas on tyres?

Try this

http://www.autopartuk.com/tyre-calculator/

8"x18" rims will take up to a 245.

I'm currently running 225/40's but am thinking of getting some 235/40's for the front.

Pirelli P-Zero Rosso's are a good all weather tyre.

Steve

what offset are they mate? and how low are you

i was to beleve 235s would rub

235's are okay a mate of mine has Porsche GT2 rims with 9 inch wide rims on the rear but i forget the tyre size!

Spiders are ET 35?

Just trying to work out my offset!As im running Porsche brakes and need 5mm spacers, so that would make it a ET30 offset and Porsche fronts are ET50 so we are looking at 20mm spacers!? can anyone running Porsche wheels confirm this?

Dont want to get 25mm adaptors if 20 are ok!

Edited 18 June, 201115 yr by dannyboy759

You need to run 225/40 to keep the gearing / speedo correct.

Yeah if your going to be picky!

Most speedos run less anyway,!

If you get a gps and compare it to your clocks they are well under and if i run the 235 then the difference will only be something like 1.6%!!!

I had 225/40/18 and at 30 on the clock driving past any speed board you get it saying 26.

I had 225/40/18 and at 30 on the clock driving past any speed board you get it saying 26.

Thats the way most clocks are anyway lol

Atleast that way round rather than the other

According to the tyre calculator: 225/40R18

Your speedometer will be 3.3% too slow. When your speedo reads 60 mph, your actual speed will be 62.0 mph

My GPS consistently puts my speedo 6mph slower than actual

cars should never be under on a reading, its normal to be up to 10% over however.

10% under means something is wrong..

I had sat nav on today on standard spiders doing 70mph on speedo and sat nav says 65mph,

When i changed wheels on my previous volvo from 16's to 17's my speedo was only 2mph out, thought thats was quiet good, oh and that was verified by sat nav and the nice mr police officer with his radar gun (t**t)

I had sat nav on today on standard spiders doing 70mph on speedo and sat nav says 65mph,

When i changed wheels on my previous volvo from 16's to 17's my speedo was only 2mph out, thought thats was quiet good, oh and that was verified by sat nav and the nice mr police officer with his radar gun (t**t)

were you in a 30 at the time

On my 18x8s ET35 225/40s rub at the back.

But no-one else seems to have this issue! Strange.

On my 18x8s ET35 225/40s rub at the back.

But no-one else seems to have this issue! Strange.

Outside the wheel or inside?

215/40/18 on 9's rear over here

Outside the wheel or inside?

They hit the arch liner on the outside.

No issues since I fitted 215/40 tyres though.

I run 215/35/18 all round on mine and they rub VERY slighty on the back.

Maybe it's cos i'm running a ET26

Edited 20 June, 201115 yr by furry

So..... what's the final verdict??!!

Going with the assumption that the wheels are OEM off-set/depth (ET35) Are we saying:

• 235/40/zr18 - front
  
• 225/40zr18 - rear
  

Steve

Ive seen a Golf today with 9.5 inch rims on and they fit fine

If you keep the offset factory they fit ok

So..... what's the final verdict??!!

Going with the assumption that the wheels are OEM off-set/depth (ET35) Are we saying:

• 235/40/zr18 - front
  
• 225/40zr18 - rear
  

Steve

OEM 7x17" spiders are ET38.

I've got 8x18" ET35 wheels on my vRS hatch fitted with 225/40R18's and the rears would defo rub on the outside tyre wall if the car was lowered or perhaps fully loaded with passengers, luggage etc !!!!

I wish now I'd done the same as Rob and fitted 215/40R18's...doh

Bill.

I know this is a year old thread, but I was wondering if you have to have 8x18's (or more) to get a bit of tyre stretch, or is it possible to get a little stretch on the spiders (without knocking the speedo out)?

Anyone ever done it on an Octavia vRS?

Hmmm a stretch on a 7j rim your going to be down to 185/175 regions

I dunno whats available but i will nose about for u mate

Quick workings uou'd really ish need

175/60/17 :(

Or

185/55/17