17 = 18 Radius Help

[Rattusmaxim]

I've just got a set fo GT4 wheels that come with tyres (which need replacing anyway) but the tyres at the mo are:

 

F - 235/40/18 and my current tyres on the Zed are - 225/50/17

R - 245/35/18 and my current tyres on the Zed are - 235/50/17

 

But putting this into http://www.tyresave.co.uk/tyresize.html says that the rears will be out by like ~5%, putting a rear of 245/40/18 seems to put it back to around 1.5-2% difference in radius, anyone know why the rears at the mo have 245/35/18s on??

 

Any help would be good as I'm looking to get the new tyres on the wheel/wheels on my car asap but obviously don't wanna affect the car in a bad way with the wrong tyres!

 

Cheers,

 

Tyler

[Ekona]

Should be 225/45/18 on the front and 245/45/18 on the rear I think. Can't see any reason why the GT4 wheels would be any different from the Rays.

[Rattusmaxim]

Seems good to me, just tried them sizes out and there's a much smaller radius difference.

 

Guess that's what I'll get put on then

[ATTAK Z]

Should be 225/45/18 on the front and 245/45/18 on the rear I think. Can't see any reason why the GT4 wheels would be any different from the Rays.

do you know what the offset is on standard rays ?

[rich5259]

From the manual,

front wheel size 18x8JJ offset 30mm

Rear wheel size 18x8JJ offset 30 - I guess these are not the Rays

Rear wheel size 18x8-1/2JJ offset 33

[Rattusmaxim]

Just had a look on 350z-tech and it has this info:

 

Rays:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 18.19lbs

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 18.62lbs

Tire: 245/45/18

 

GT4:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 24.4

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 25.8

Tire: 245/45/18

 

So going by that, both wheels are the same except in weight, has same tyre size which is good too.

[ATTAK Z]

Just had a look on 350z-tech and it has this info:

 

Rays:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 18.19lbs

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 18.62lbs

Tire: 245/45/18

 

GT4:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 24.4

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 25.8

Tire: 245/45/18

 

So going by that, both wheels are the same except in weight, has same tyre size which is good too.

and just look at the weight of the Rays .... that was a major selling point when I bought my car 6 years

ago

 

Has anyone come up with a lighter wheel than the Rays ?

[Greekman]

Just had a look on 350z-tech and it has this info:

 

Rays:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 18.19lbs

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 18.62lbs

Tire: 245/45/18

 

GT4:

 

Front

Size: 18x8.0

Offset: +30mm

Weight: 24.4

Tire: 225/45/18

Rear

Size: 18x8.5

Offset: +33mm

Weight: 25.8

Tire: 245/45/18

 

So going by that, both wheels are the same except in weight, has same tyre size which is good too.

 

+1.

Also work fine with 40 profile.

the rays are extremely light. much lighter than any other stock Z rims.

[Rattusmaxim]

That is a big difference in weight but if I'm honest, I bought the wheels purely on looks

 

Also you say 40 profile is ok, do you run 40? Would probably look a bit better than 45 but then I want good wear and correct speed/mileage etc.

[Ekona]

40 can throw the TCS systems out, don't run those unless you're happy to run the Zed with them turned off all the time. Just get the correct size tyres in the first place, save yourself any hassle

 

 

And you do know that the wheels are the worst place to add weight don't you, will definitely make your car slower

[Rattusmaxim]

At the mo I got the pants 17" ones which are almost the same weight as the new wheels so shouldn't affect it much (in theory )

[Greekman]

That is a big difference in weight but if I'm honest, I bought the wheels purely on looks

 

Also you say 40 profile is ok, do you run 40? Would probably look a bit better than 45 but then I want good wear and correct speed/mileage etc.

 

yes i went through 3 sets of ps2s 40 prof, did a fair few track days with them and had no probs whatsoever with the ESP m8

 

now i v got 19inch wheels and the rays are getting refurbed and wrapped with 888s for track days as they are so light.

[Rattusmaxim]

Anyone had any experience with Avon ZZ3s? Thinking about putting them on, seem like a good set of mids