What size tyre?

rob180

Anyone here know what size would the tyre be if i opt for the 20inch wheel on the Opel Astra GTC? Thinking of getting the 2.0 CDTI.
Thanks

Guy:Incognito

20 inch wheels on an astra? I'd imagine whatever the width and sidewall height of the tyre is it will be put on from a tin with a paintbrush.

colm_mcm

235/35/20 or so. Budget for a chiropractor too.

MugMugs

rob180 wrote: »

Anyone here know what size would the tyre be if i opt for the 20inch wheel on the Opel Astra GTC? Thinking of getting the 2.0 CDTI.
Thanks

Please post pics when you get them???????

rob180

colm_mcm wrote: »

235/35/20 or so. Budget for a chiropractor too.

lol i think the 19inch wheels are 235/35/19 ,so would the 20inch be wider still? Was looking at the standard 18inch wheels and it doesn't look right. The wheel arches, to my eyes, needs bigger wheels.

colm_mcm

20s will look silly. Try lowering it.

heate

How much is a quality 20" tyre going to cost you because your going to be replacing them often enough

rob180

MugMugs wrote: »

Please post pics when you get them???????

Will do. The 19inch wheels are €525 extra(not bad) and the 20inch are €1050 extra. Just have to factor in the cost of a 20inch tyre and it's availability if i want the 20inch wheel

rob180

colm_mcm wrote: »

20s will look silly. Try lowering it.

I wouldn't mess with a new car, well not until it's warranty run out anyway.

colm_mcm

rob180 wrote: »

I wouldn't mess with a new car, well not until it's warranty run out anyway.

Putting on 20s is messing with it. I'd imagine Opel offer a lowering kit that doesn't invalidate the warranty.

rob180

heate wrote: »

How much is a quality 20" tyre going to cost you because your going to be replacing them often enough

Well , at the moment i've GoodYear Eagle F1 Asymmetric 2 on my Astra OPC and the wheels are 18inch 225/40 tyres. Each tyre cost about €150. That's why i wanna know the size of the tyre for the 20inch wheels

Saab Ed

Here's a rough formula to upsizing a wheel rim.

For each increase in wheel diameter then take 10 off the sidewall profile height. For each increase of 10 in tyre width (i.e the first number in the tyre size) then take another 5 off the sidewall profile height. This is because the sidewall profile height is an aspect ratio and not an actual measurment i.e 195 by 70 by 15 meens that the sidewall height is 70% of the 195.

So as a simple example to increase the rim height, a 195/65/15 becomes a 195/55/16 becomes a 195/45/17.

Or for wider tyres a 195/65/15 becomes a 205/60/15 becomes a 215/55/15.

Its not a perfect science but its close enough. Dont forget to make sure that you keep atleast the same speed rating and load rating as what was fitted as original equipment.

Here's a little help on that .....

http://www.bridgestone.com.au/tyres/passenger/care/markings.aspx

vectra

rob180 wrote: »

lol i think the 19inch wheels are 235/35/19 ,so would the 20inch be wider still? Was looking at the standard 18inch wheels and it doesn't look right. The wheel arches, to my eyes, needs bigger wheels.

Order it lowered with 18's

colm_mcm

Camskill would be 1150 for 4 michelins

coylemj

colm_mcm wrote: »

235/35/20 or so. Budget for a chiropractor too.

These might be cheaper than the chiropractor...

colm_mcm

coylemj wrote: »

These might be cheaper than the chiropractor...

Roofline very low on the gtc though.

vectra

Saab Ed wrote: »

Here's a rough formula to upsizing a wheel rim.

For each increase in wheel diameter then take 10 off the sidewall profile height. For each increase of 10 in tyre width (i.e the first number in the tyre size) then take another 5 off the sidewall profile height. This is because the sidewall profile height is an aspect ratio and not an actual measurment i.e 195 by 70 by 15 meens that the sidewall height is 70% of the 195.

So as a simple example to increase the rim height, a 195/65/15 becomes a 195/45/17.

Slightly out there
195/65/15 becomes 225/45/17

coylemj

colm_mcm wrote: »

Roofline very low on the gtc though.

Possible solution? Might need to invest in some rain gear...

Saab Ed

vectra wrote: »

Saab Ed wrote: »

Slightly out there
195/65/15 becomes 225/45/17

Don't think so. You'll completely change the rolling radius using a 225.

rob180

colm_mcm wrote: »

Camskill would be 1150 for 4 michelins

Wow , that's over €255 a corner. The 19's looks more tempting now. Thanks for the input folks.

vectra

Saab Ed wrote: »

Don't think so. You'll completely change the rolling radius using a 225.

Did it recently on the Toledo

195/65/15 went to 225/40/18 which in turn is the same as 225/45/17

Saab Ed

vectra wrote: »

Did it recently on the Toledo

195/65/15 went to 225/40/18 which in turn is the same as 225/45/17

You're dead right. Found this little gadget

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

R.O.R

Had an Astra sport toured last year for a couple of weeks. Think that was running the 19s, and that was a bit rough on older bits of motorway yet alone going off the beaten track in Galway.

Looked well but I can think of better things to spunk over a grand on than 4 tyres.

TopCatKK

If you think the 19s look lost underneath it increase the aspect ratio - that is if the size is 235/35/19 look for something in a 40 series. This increases the size of the sidewall of the tyre and will fill the arch a bit better.