What Size Tyres ?

[Wacky Dee]

replacing the stock rims with a set of 18x8.5's What's the recommended size of tyre for this size/width of wheels? I'll do the research on the tyre brands myself as there'a a LOT of discussion in that big sticky thread above .. I just need to know the right size. Cheers

Also if someone could just quickly explain the tyre size lingo and what it means that'd be cool ie. 235/40/R17 (or some such)

[Wacky Dee]

anyone?? looks like I might be getting my new rims today so i'll need to go out and buy some rubber .. I've pretty much decided on Federal SS 595's but I'd like to know what size I'm looking at so as to be able to ring around and find the best price.

[Scottydoo]

Im running Federal SS 595's on my stock rims atm and they are a great tyre for the price.

Im running 235/45/17

Im no expert but here is my basic understanding

235 is the width

45 is the sidewall height in relation to the width

17 is obvisouly the rim size.

I've heard you can go as big as 275's on the back of r34's but you'd probably have to get your guards rolled. Im going 265/30/19's on the front and 235/35/19 on the back with my new mags and i'll be getting mine rolled to be safe.

[r33cruiser]

tyre calculator

might help

http://www.1010tires.com/TireSizeCalculator.asp

[Wacky Dee]

the calculator doesn't seem to take into effect new rim width .. stockies are 17x7.5" and I'm going up to 18x8.5

[Wacky Dee]

I've heard you can go as big as 275's on the back of r34's but you'd probably have to get your guards rolled. Im going 265/30/19's on the front and 235/35/19 on the back with my new mags and i'll be getting mine rolled to be safe.

you mean you're going 235 at the front and 265 at the rear or are you really putting wider tyres at the front? Speaking of which, why is it so common to see people put wider tyres at the back when the rim width is the same ??

[Wacky Dee]

well my new rims are here all ready to go yay! Now I just need to decide on the tyres ... I see a lot of good responses on the Federal 595SS so I might as well go with the flow. Now just to find the right size

The stock rims are only 17x7.5 but the tyres on them are 225/45/17 - thats like 8.85" wide tyre..doesn't that seem a bit wide for a 7.5" rim?

Edited May 1, 2008 by Delta Force

[bubba]

Not at all.. I'm running 245/40/17's on my 17x7.5 rims..

[Wacky Dee]

does anyone know what the stock tyre sizes are on the stock R34 GT-T wheels?

[bubba]

I believe they are 225/45/17.. which is what I run on the front (I have 34 gtt wheels).

[Wacky Dee]

cheers

according to the tyre size calculator I should be OK to get 255/35/R18 The diametre difference is negligible (0.2%) What does everyone reckon? is this a good size for fronts AND rears ?

[bubba]

That's pretty bloody fat for the front... I'd be inclined to stick somewhere around 235.

[Wacky Dee]

what about 235/40/18 on the fronts and 255/35/18 on the rears? Or would that be too weird a setup?

that would give me a 1cm larger diameter at the FRONTS and 1.5% in speed difference (rears faster) and 0.5cm difference in sidewall height (fronts higher)

Edited: fronts were meant to be 235/40 not 45

Edited May 1, 2008 by Delta Force

[Sydneykid]

what about 235/45/18 on the fronts and 255/35/18 on the rears? Or would that be too weird a setup?

that would give me a 1.3cm larger diameter at the rears 1.5% in speed difference (rears faster) and 0.5cm difference in sidewall height (fronts higher)

Why do you want to put a smaller tyre on the front, do you want it to understeer?

Over 60% of the weight is on the front tyres.

Cheers

Gary

[Wacky Dee]

Why do you want to put a smaller tyre on the front, do you want it to understeer?

Over 60% of the weight is on the front tyres.

Cheers

Gary

Sorry I've fixed that typo. it's the fronts that would have a 1cm larger diameter with that sort of setup ... is that any better or still stupid? Should I just go 235/40 front and rear?

[Wacky Dee]

K I've decided to try the Maxxis Z1's due to price being only $179 per corner and me not being able to find ONE negative review for them plus they seem to have won some Wheel's price/performance test.

Now just to get the size right !!

[Scottydoo]

you mean you're going 235 at the front and 265 at the rear or are you really putting wider tyres at the front? Speaking of which, why is it so common to see people put wider tyres at the back when the rim width is the same ??

Yeah my bad, was typing up a quick response while i was 'working' and didn't check it before posting

Bigger tyres on the back is an effort for more traction i'd say, yeah it might/probably will understeer but who really races their skylines on a street setup?...well their daily driven skylines anyway.

[Wacky Dee]

I'll speak to the BJ guy tommorow and see what he reckons... I'd "like" 235/40/18 at the front and 255/35/18 ar the rear - but that means the fronts will be 1cm bigger (ie. sidewall 0.5cm higher). I'm not sure if that's a bad thing - I'll see what he reckons and go from there. Thanks all.

Edit: or maybe instead of the above setup, I'll go 245/40/18 all around. That'll give me a higher side wall (better ride comfort??), it's only 1.9cm extra diameter and 3% slower than speedo says (driving 97kmh when it says 100kmh)

Edited May 1, 2008 by Delta Force

[br3ndan]

i run 235/45/17 at the front

255/40/17 at the back

I heard its becuase u want to keep the speedo reading correctly... due to the speed is taken from the rear tyres...

[Wacky Dee]

yeah but you drive a different car (r33 gtst?).. unless its stock wheels are 17"s and tyres 225/45 you cannot compare the two.