OEM 18's for AH Astra

[entice]

Hi all, just a quick update.

Just picked up my OEM 18's from spare parts so I can have them all ready for the new car.

Some interesting bits of info.
They are actually a RONAL wheel, with Ronal and GM badging internally.
I am suprised as to how little they weigh (and hence I suspect why they cost so much). I imagine that handling will not be adversely affected due to their weight. I lifted an HSV wheel as a comparison and I imagine they are almost half the weight of teh HSV wheel
Et is 37 (offset).

they are an 18 x 7.5", and I think I'll be going with a 235/40/18 tyre (much more choice..eg Firestone TZ100, Firestone Wide Oval, Bridgestone G3, Bridgestone SO3) as opposed to the 225/40/18 (SO3 and G3). as a guide, the TZ100 is half teh cost of the SO3. Once done I will source a Tech 2 and sort out the speedo calibration.

Oh, and yes, they do look magnificent!

[Red AH SRI T]

if u are buying the OEM 198's i dont think u will need the tech 2 to sort out the speedo

[MK]

congratulations on the purchase... those wheels look good on Astra H.

You mentioned "speedo calibration" once the wheels\tyres are fitted.
Is it compulsory?
With the 18's on is the speedo really that much out\off that a calibration is required?
Would a calibration be required with 17's?
Is the speedo over or under in showing the correct speed?

I ask because back in the days of my commodore owning days i used to have 17's and then 18's on and never even heard of speedo calibration being required.

[Red AH SRI T]

the bigger the wheel, the smaller the tyre in profile, so the circumfrence should stay the same, therefore not requiring the speedo to be recalibrating

[pred8r]

Going to a wider wheel without changing to a lower profile will change speedo reading IIRC.

[aussie_in_london]

possibly the best looking wheel Vxl/Opel released, stay far away from gutters though lol, the spoke of the rim protrudes alittle to far out, found out that a few times with mine but easily repaired but fantastic looking wheels, starting to see em on a few GSi's about now.
This is where they started their life same with the astra H headlights
http://i5.photobucket.com/albums/y179/aussie31/img021.jpg

[R3N]

the bigger the wheel, the smaller the tyre in profile, so the circumfrence should stay the same, therefore not requiring the speedo to be recalibrating

thats IF you get tyres with a smaller profile that maintains the same rolling radius with the bigger rims

[entice]

under the garage section of www.miata.net there is a fabulous wheel/speedo calibration tool that can be found. a 225/40/18 is a more suitable tyre than the 235/40/18 which will have an error of around 2% from standard (underestimating the speed). but there is greater variety of choice in the 235/40 c.f. 225/40


http://www.miata.net/garage/tirecalc.html

[Red AH SRI T]

thats IF you get tyres with a smaller profile that maintains the same rolling radius with the bigger rims


hehehe, u know what i meant ;)

[Streetlights]

Yep, it's all about the rolling diameter. If it changes, then the speedo will need calibrating. If it doesn't change, you're good to go.

[BassyAstra]

You entice us with your words and then you dont put up any pictures, entice, CMONNNNNN. :)


Love those pics AUSSIE..

[entice]

???

picks of the alloys in the boxes???

seriously?

u can see them on the holden website...

dunno when the car will be rrady..end of month I am told

Reversing sensors are on backorder from GMHA aswell...so that may take an extra month or so aswell.

[BassyAstra]

Ahhh sorry..

[entice]

no probs...but I will try to take images and part numbers for those interested

[RedVYIISS]

Et is 37 (offset). they are an 18 x 7.5", and I think I'll be going with a 235/40/18 tyre (much more choice..eg Firestone TZ100, Firestone Wide Oval, Bridgestone G3, Bridgestone SO3) as opposed to the 225/40/18 (SO3 and G3). as a guide, the TZ100 is half teh cost of the SO3. Once done I will source a Tech 2 and sort out the speedo calibration.

Oh, and yes, they do look magnificent!

Entice, 235/40 is a bit wide for a 7.5 rim, I know Holden put them on 8" rims but the tyre manufacturers actually recommend 8.5" rims for 235's. (BTW, my first post. Hiya Astra owners. I bought the Mrs an AH Astra December 2004, just over a year old now. She loves it and I must say, I don't mind driving it myself! She's after a set of mags for her b'day. I'm looking to put 17 x 7.5" on it for her. Haven't decided on style yet hence looking here.)

[entice]

yep.. had a chat to a few in the know, and the 235/40/18 is what the HSV's all get I am told.

the only reason why I was looking at them is that they are the only tyres in teh Bridgestone/Firestone range that meet the 91 load rating specified for the car.

BUT,

have no fear, I have found a "fix" for this problem, and am able to go for the 225/40/18 in an 88 load rating and still remain legal. That means SO3, and G3 are available and more importantly, LEGAL for the car (once the fix is employed)

[RedVYIISS]

Re tyres, I'd be giving the Firestone's a wide berth. A mate's got them on his SS and they're pretty ordinary.

We replaced a pair on his and a pair on mine at the same time and both fitted Kumho Exta Sport's, and both very happy, particularly given price paid (in the premium tyre testing that Motor did the Kumho's came out in the middle of the pack however the tyres they were comparing them with were twice to three times the price). HSV have recently changed from Pirelli P Zero Rosso's to Yokohama Advan Sports. The Yoki's are getting rave reviews as well, though still a lot more expensive than the Kumho's.

I've had Nankang NS2's on the SS as well. While not as good as the Bridgestone SO3's or Kumho's they're not bad, and remarkably good value for money. All the above in 235/40 18" though.

[ROCCO]

For all those after rims at a decent price I foudn this website http://www.wheelking.com.au/wheel.htm
they have a listing for the AH as well i'm looking at the Type R ROH rims for my black astra AH

[entice]

but you cant buy the rims unless you buy tyres from them aswell...

tried that avenue.