Help With Tyre Sizes

[Red Sky II]

Having likely found the wheels to get, now the question of tyre size arises.

OEM tyres on a S2 Stagea is 225/50/16 which gives a diameter of 631.19mm

Looking at 18" x 8" rims

Possible tyre choices (based on 1010tires.com) are:

225/40/18 - diameter of 637.03mm

235/40/18 - diameter of 645.16mm

245/40/18 - diamater of 653.03 (per tyre retailer)

245/35/18 - diameter of 628.65mm

Therefore based on the above, it seems the closest tyre would be the 245/35.18 and then the 225/40/18 (although have noticed in previous threads that the 225/40/18 seems to be the recommended tyre size).

Will check with dealer on the 245/35/18 size. The tyre retailer also stated that the 225/40/18 would be too small in overall diameter whereas the above suggests it is actually a larger diameter than the OEM version.

For those who are running 18" rims (or just know this stuff) can you advise on what tyre sizes you are running and whether you have noticed any problems?

Any help woule be appreciated

Cheers, Al

[yokotas13]

if you HAVE to base it on that

I dont listen to tire manufacturers

they tell people things dont work becuase most people are retarded and do stupid things.

225x40

if you want to go lower you can go 215/40

but some people think its unsafe. its not.

But hte need to go with a smaller tire has to do with a few things

First

How low is your car?

Im running small tire sizes becuase i like to tuck tires in my wheel wells.

if you dont need to do that

go with a 245 or so its "Safe" or whatever

but larger tires on 18s looks funny. and it will make your car sit higher.

Edited February 18, 2007 by yokotas13

[munchstagea]

Hi Alan,

Pretty sure you are asking the question in regards to keeping your speedo accurate (which is very important in Australia Grant) and you are dead on the money, the 225/40/18 is the closest you can get to the factory rolling distance in a standard 18" tyre. Although the 235/45?/18 is a more common size and can be a lot more cost effective solution without getting too far away from the factory rolling distance.

You can use the following page to work out the difference between the sizes.

http://www.carbibles.com/tyre_bible.html (scroll down a long way).

I have a S1 running 225/40/18 tyres and under the freeway speed check I read 97 when sitting dead on 100km/h so I am happy with that size.

Cheers

Luke

[GorGasm]

im running 235/40/18's no worries. I also though the OEM size was 205/55/16

[Red Sky II]

Luke, yeah it is in relation to speedo accuracy to get the closest to the OEM diameter

Logan, my tyre placard has both the 205/55/16 and 225/50/16 on it and I have the 225's on there at the moment

So still divided opinion it seems

[yokotas13]

why is the speedo so important?

Keep a second set of wheel so when inspection comes around, you have a stock rolling diameter wheel.

i do it. its important in japan too

[mike40sydney]

why is the speedo so important?

Keep a second set of wheel so when inspection comes around, you have a stock rolling diameter wheel.

i do it. its important in japan too

spedo is important here grant because unless u run a gps all the time im buggered if ill fork out the huge dollars for speeding fines here in nsw and believe me ive been done for 5 bloody klm over the limit.not in the stag tho was by a fixed speed cam

[yokotas13]

thats anal.

ok now why i know why some aussi cars look like they do then. that cleared up alot of stuff i guess

[Red Sky II]

As Mike said depending on other things, you can get fined for 2kmh over the limit in WA so having it as close to OEM is a factor over here.

So it seems a toss up between 225 and 235's without any mention of the 245's - would 245's actually fit?

[yokotas13]

it does, its just huge

i like the 25 size, it will give it a little stretch, and stretch is good, as long as your low. if your not go 35

[GoldZilla]

Dunno, personally, I've always hated the stretched look of a tyre.

And larger tyres on 18's will only look stupid if you pick the wrong profile for the width...

[yokotas13]

stretch isnt for look, its for fitting.

when they do it for looks its stoopid

[sy300]

I have 18X8 and 235/40's fitted.

My speedo reads pretty much spot on (+/- 2km/h).

I also am not a fan of the stretched look with tyres. I like it when the edge of the rim and tyre are even. The stretched look just makes it look like you are too cheap to buy a set of proper width tyres (IMHO).

I would have liked 245's, but I heard that they don't fit very well on the front.

[yokotas13]

but the problem is you guys ar emissing the point and advantages of streching

i wont get into it, but its just not for looks. and not only for fittingh tires. there are performance advantages.....

but then again id image most stagea owners really arent worried about handling (not being derrogatory, its 3700 lbs car lol its not ideal)

either way, any of your options are viable, some will look remarkabley differnt than others and fill up the well more.

[Ska]

Sorry to hijack thread but will rims that fit stagea's fit R32 5 stud?

[yokotas13]

yeah they both use around the same offsets stock around +30s

[Red Sky II]

I thought the stock offset on a stagea was +40 (well that is what the manual says anyway) and that is for a 16x7 rim

[yokotas13]

have you noticed you can sleep in your wheel well?

at a minimum go with a +30 al around on a 8j wheel

[Duncan]

I'm running 245/45/17, they fit nice, plenty of room inner and outer. And the speedo is more accurate than standard (checked to GPS speedo).

Don't forget ADRs allow speedos to read up to 10% higher than actual speed (so you may be going slower than you think)

[GoldZilla]

I'm running 245/45/17, they fit nice, plenty of room inner and outer. And the speedo is more accurate than standard (checked to GPS speedo).

Don't forget ADRs allow speedos to read up to 10% higher than actual speed (so you may be going slower than you think)

Correct. I found using GPS that my speedo is about 4km/h optimistic, which is good in a way because I at least know that when I think I'm doing a certain speed, I'm actually travelling below it, so I won't get any grief from Cops or speed cameras, etc.

The speedo on my old man's Camry, however, is VERY accurate when compared to GPS readings!