Tyre width to wheel reference chart

[Black Betty]

All recommendations are to the letter of the law, enforced by the ETRTO (European Tyre and Rim Technical Organisation)

Tyre Dim'sions/Recom'd Width/Operational Parameters
55 Series
205/55/15………… 6 ½ J………………….. 5 ½ J – 7 ½ J
205/55/16………… 6 ½ J………………….. 5 ½ J – 7 ½ J
215/55/16 ………… 7 J…………………… 6 J – 7 ½ J
225/55/16 ………… 7 J …………………... 6 J – 8 J
205/55/17………… 6 ½ J …………………. 5 ½ J – 7 ½ J
215/55/17 ………… 7 J …………………… 6 J – 7 ½ J
225/55/17 ………… 7 J …………………… 6 J – 8 J
235/55/17 ………… 7 ½ J …………………. 6 ½ J – 8 ½ J
215/55/18 ………… 7 J …………………… 6 J – 7 ½ J
50 Series
195/50/15………… 6 J…………………… 5 ½ J – 7 J
205/50/15………… 6 ½ J …………………. 5 ½ J – 7 ½ J
205/50/16 ………… 6 ½ J…………………. 5 ½ J – 7 ½ J
225/50/16 ………… 7 J …………………... 6 J – 8 J
205/50/17 ………… 6 ½ J…………………. 5 ½ J – 7 ½ J
45 Series
225/45/16 ………… 7 ½ J…………………. 7 J – 8 ½ J
245/45/16 ………… 8 J …………………… 7 ½ J – 9 J
205/45/17 ………… 7 J………………….. . 6 ½ J – 7 ½ J
215/45/17 ………… 7 J …………………… 7 J – 8 J
225/45/17 ………… 7 ½ J…………………. 7 J – 8 ½ J
235/45/17 ………… 8 J …………………… 7 ½ J – 9 J
245/45/17 ………… 8 J …………………... 7 ½ J – 9 J
225/45/18 ………… 7 ½ J …………………. 7 J – 8 ½ J
235/45/18………… 8 J …………………… 7 ½ J – 9 J
245/45/18 ………… 8 J …………………... 7 ½ J – 9 J
255/45/18 ………… 8 ½ J…………………. 8 J – 9 ½ J
40 Series
215/40/17 ………… 7 ½ J…………………. 7 J – 8 ½ J
225/40/17 ………… 8 J…………………… 7½ – 9 J
235/40/17 ………… 8 ½ J …………………. 8 J – 9 ½ J
245/40/17 ………… 8 J …………………… 8 J – 9 ½ J
255/40/17 ………… 9 J …………………… 8 ½ J – 10 J
265/40/17………… 9 ½ J …………………. 9 J – 10 ½ J
215/40/18………… 7 ½ J…………………. 7 J – 8 ½ J
225/40/18 ………… 8 J…………………. .. 7 ½ J – 9 J
235/40/18………… 8 ½ J…………………. 8 J – 9 ½ J
245/40/18………… 8 ½ J …………………. 8 J – 9 ½ J
255/40/18 ………… 9 J ………………….. .8 ½ J – 10 J
265/40/18 ………… 9 ½ J …………………. 9 J – 10 ½ J
275/40/18 ………… 9 ½ J …………………. 9 J – 11 J
225/40/19………… 8 J …………………… 7 ½ J – 9 J
235/40/19………… 8 ½ J…………………. 8 J – 9 ½ J
245/40/19………… 9 J …………………… 8 J – 9 ½ J
255/40/19………… 9 J…………………… 8 ½ J – 10 J
35 Series
225/35/17………… 8 J …………………… 8 J – 9 ½ J
245/35/17………… 8 ½ J …………………. 8 J – 9 ½ J
215/35/18 ………… 7 ½ J…………………. 7 J – 8 ½ J
225/35/18 ………… 8 J …………………… 7 ½ J – 9 J
245/35/18 ………… 8 ½ J…………………. 8 J – 9 ½ J
255/35/18 ………… 9 J …………………… 8 ½ J – 10 J
265/35/18 ………… 9 ½ J …………………. 9 J – 10 ½ J
275/35/18 ………… 9 ½ J…………………. 9 J – 11 J
285/35/18 ………… 10 J …………………. 9 ½ J – 11 J
225/35/19 ………… 8 J………………….. . 7 ½ J – 9 J
235/35/19 ………… 8 ½ J …………………. 8 J – 9 ½ J
245/35/19 ………… 8 ½ J …………………. 8 J – 9 ½ J
255/35/19 ………… 9 J …………………… 8 ½ J – 10 J
265/35/19 ………… 9 ½ J …………………. 9 J – 10 ½ J
275/35/19 ………… 9 ½ J …………………. 9 J – 11 J
285/35/19 ………… 10 J …………………. 9 ½ J – 11 J
30 Series
255/30/18………… 9 J …………………… 8 ½ J – 9 ½ J
285/30/18………… 10 J …………………. 9 ½ J - 10 ½ J
255/30/19 ………… 9 J …………………… 8 ½ J – 9 ½ J
265/30/19 ………… 9 ½ J …………………. 9 J – 10 J

[hiten86]

You know - i've never understood these - never

[SSense]

Same here :dunno: thats why im quiet and still thinking what am i actually reading

[SewerSideUp]

It's the width of the rim/tire(205/225/255) relative to the tire profile or height(55/50/45/40...) and rim size (17/18/19).

This is a chart that tells you what should work with what so you want have a deformed looking rim and tire combo. And a safe one too.
But, don't mistake this with E.T. Offset. That's a different story.

Get it ?

[Haissam]

i know all about wheels & tire sizes..

PM me for any help :)

[SSense]

It's the width of the rim/tire(205/225/255) relative to the tire profile or height(55/50/45/40...) and rim size (17/18/19).

This is a chart that tells you what should work with what so you want have a deformed looking rim and tire combo. And a safe one too.
But, don't mistake this with E.T. Offset. That's a different story.

Get it ?

Lil bit, anyways thanks for your genuine info :thanks2:

[SSense]

Ive got 245/40/ ZR18 front
and 275/35/ZR18 rear
Thats the standard size for M5 tires, dont think I need to make any further changes if I stay with the stocks :nono:

[hiten86]

Whats the story with E.T and offset bro?

[SSense]

Whats the story with E.T and offset bro?

The offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel. The offset can be one of three types (measured in millimeters).*

Zero Offset
The hub mounting surface is even with the centerline of the wheel.

Positive
The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.

Negative
The hub mounting surface is toward the back or brake side of the wheels centerline. "Deep dish" wheels are typically a negative offset.

If the offset of the wheel is not correct for the car, the handling can be adversely affected. When the width of the wheel changes, the offset also changes numerically. If the offset were to stay the same while you added width, the additional width would be split evenly between the inside and outside.

[hiten86]

*sigh*
thanks ssense!
I realy think i need to learn more now.
Or take practical classes perhaps!
or 'study' cars.
Thanks anyways man!
did help a little

[SSense]

*sigh*
thanks ssense!
I realy think i need to learn more now.
Or take practical classes perhaps!
or 'study' cars.
Thanks anyways man!
did help a little

Anytime bro :thanks:

[Black Betty]

Nice thread,
But i need to know what do you mean By Operational Parameters

As Far as I understand it from the chart, the “Operational Parameters” are the +- tolerances for the “Recommended Width”
Please correct me if I’m wrong, I just thought this would be useful to some of you guy’s involved in motorsport’s.

[Ayham]

I understood it like that as well...

For those of you who want to exactly know what their tires and rims say:

On a tire you'd read: 225/45/17 for example. 225 is the tire width (225 < 265 < 315). 45 is the side profile thickness (45 > 40 > 35). 17 is your rim diameter.

On a rim you'd read: 17 x 8J x ET38. 17 is like above. 8J is the rim width (7.5J < 8J < 9J). ET is the rim offset, i.e. how much further out is it pushed in reference to the wheel hub or your fender for visual reference (ET38 is at the edge of the fender's outer face in an E36, ET45 is 'tucked in' and will not rub with the fender; given in both cases the car is lowered the same).

Sometimes you'll read PCD 5x120 on a rim, it's the Pitch Circle Diameter; how many bolts are on (5) and how many degrees they're apart from one another (120).

That's more or less it :)

[SewerSideUp]

Simplified nicely !

[hiten86]

*hail* ayham!
thank you!
made it a lot easy for me to understand what those numbers really mean