Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[blackviper90210]

Hi all,

Can someone in simple terms explain what the numbers etc mean regarding wheel sizes please?

I used to to think years ago, it was just diameter and tyre wall sizes 

I see tyres being sold with things like:

1)  8J x 18
2)  ET39
3)  PCD??

etc etc

Also, what is the range, if there is one, for the Omega?


TIA

[RobG]

http://www.nice-wheels.co.uk/pcdandoffset.html
8 x 18 is 8" wide rim (where the tyre sits), 18" dia of wheel

Omega PCD 5 x 110,  Offset 35-38,   Bore 65.1
 


 

[blackviper90210]

Just reading your link now Rob, cheers!

So ET is the offset then and the Omega can be between 35 - 38.  Is that right?

[RobG]

Just reading your link now Rob, cheers!

So ET is the offset then and the Omega can be between 35 - 38.  Is that right?

Mig will take an offset of anything between 30-45, obviously dependent on spacers/rim size/tyre size

[blackviper90210]

Ahhhhhh

Not so simple anymore, lol.

Thanks for your help Rob

[RobG]

As an example, if you fit wheels with an ET of 45 ideally you`ll need something like 25mm Eibach-pro spacers on the rears and 18mm at the front which will mean the rears will be out 18mm further and the fronts 11mm.

[RobG]

Ahhhhhh

Not so simple anymore, lol.

Thanks for your help Rob

What did you have in mind fitting?

[blackviper90210]

I'm torn at the moment.

Robsey has a set of Irmscher 18's available, I don't know the et etc of them, but obviously they'll fit my car, but.... I've just been given first dibs on a set of 18's off a Vx VXR, 8Jx18 ET39

I like both, both at the same price, but the VXR's don't need new tyres....

[RobG]

I'm torn at the moment.

Robsey has a set of Irmscher 18's available, I don't know the et etc of them, but obviously they'll fit my car, but.... I've just been given first dibs on a set of 18's off a Vx VXR, 8Jx18 ET39

I like both, both at the same price, but the VXR's don't need new tyres....

[blackviper90210]

Now if you'd have said no, that would of made my decision easier

Bo lux

[RobG]

Now if you'd have said no, that would of made my decision easier

Bo lux

Just my opinion but I can`t see the fascination with "everything Irmscher"

[blackviper90210]

It's not the name for me, I just happen to like the design of the softstar alloys, then these vxr's come along

[RobseyMV6]

It's not the name for me, I just happen to like the design of the softstar alloys, then these vxr's come along

Don't have to buy my set Dave, really don't mind, but you haven't fitted after market bumper and you clearly want irmscher omega, without the alloys irmscher like the boy's / chris irmscher on this site, if it's not irmscher complete it's going chav route not what car is. Vauxhall had it in booklet years ago with the wheels on.

[blackviper90210]

It's not the name for me, I just happen to like the design of the softstar alloys, then these vxr's come along

Don't have to buy my set Dave, really don't mind, but you haven't fitted after market bumper and you clearly want irmscher omega, without the alloys irmscher like the boy's / chris irmscher on this site, if it's not irmscher complete it's going chav route not what car is. Vauxhall had it in booklet years ago with the wheels on.

You have a point there Rob, no argument there

I'd prefer to have the softstars, otherwise I wouldn't have asked you about them.  It's just logistics getting them from you and then fitting new boots to them, which is my headache
With the VXR's, the tyres are not needing changing and means they could go straight on.

Why couldn't you be bloody closer and I have a full time job 

[2woody]

so, all you need to know is ........

8 is the rim width in inches - and that's between the tyre seating beads inside the actual rim, not the overall width that you'd measure with a tape or rule

J is the rim profile, the actual part of the rim that the tyre bead seats on - there are different profiles for different applications. K is for smaller rims, J is the most common, but there are others for different things such as off-roading.

ET or offset is the amount that the hub face is either inside or outside of the geometric centreline of the wheel. For instance, front-wheel-drivers have CV joints packaged inside the wheel and therefore need a larger offset than proper-wheel-drive cars.

if you're swapping, then probably the offset is the most important thing. Remember, too that the larger diameter, the lower profile tyre you'll need - and that'll affect both handling and comfort.