Wheel Offset

[hotrat]

Why is it that when i look up a cars wheel offset there are two figures given. It will say for example, offset 35-42. or offset 35 to 42. should it not just be the one figure, anyone know what this is about. thanks.

[andyiley]

I suspect it means that with (for arguments sake) 7 inch wheels fitted an offset anywhere in that range will fit, less fouls the inner wing, more fouls the wheel arch or vice versa.

[Mave]

Can you give an example? I'd expect the manufacturer to keep the offset consistent even with different tyre widths, to keep the suspension geometry the same.

[TheRealFingers99]

You'll see variable figures quoted on websites where either wheel sellers are telling you that such and such a wheel will fit (well, sort of), or different varieties of a model have different ETs. Treat both with extreme suspicion. The only correct ET is the one stamped on the OE wheel of your car.

[hotrat]

Here's an example of what i mean, two figures for the offset. i guess i'll need to read up on how to get the offset from the wheel i'v got on the car. thanks all. http://www.alloywheels.com/BMW-X5-Series-E53-Alloy...

[TheRealFingers99]

hotrat said:

Here's an example of what i mean, two figures for the offset. i guess i'll need to read up on how to get the offset from the wheel i'v got on the car. thanks all. http://www.alloywheels.com/BMW-X5-Series-E53-Alloy...

No figuring to be done. It's generally (and certainly in Germany) a legal requirement that the ET be stamped on the wheel, somewhere. Where varies -- FIAT and Compomotive generally have it on the outside, more often, you'll find it on the inside. But chances are very high that it'll be there. Sometimes manufacturer's handbooks will have it (and maybe alternatives) listed.

[PositronicRay]

Try here for info on genuine alloys.

http://www.alloywheelsdirect.net/bmw_alloy_wheels/...

[Miner49er]

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

[hotrat]

Miner49er said:

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

Would go with that.

PositronicRay said:

Try here for info on genuine alloys.

http://www.alloywheelsdirect.net/bmw_alloy_wheels/...

I used bmw as a example the car i'm after is a mr2, i was to embarrassed to say but can't find Toyota on there. i'll do what Fingers says and look on a standard rim for it's offset and if i want to dish it out 10mm from standard then i will take 10mm off the standard offset when i order the wheels, if you know what i mean. asking more than telling lol

[hotrat]

edit

Edited by hotrat on Monday 20th October 21:26

[TheRealFingers99]

hotrat said:

I used bmw as a example the car i'm after is a mr2, i was to embarrassed to say but can't find Toyota on there. i'll do what Fingers says and look on a standard rim for it's offset and if i want to dish it out 10mm from standard then i will take 10mm off the standard offset when i order the wheels, if you know what i mean. asking more than telling lol

For the MR2s, best go to imoc or MR2OC. Plenty of threads on there about wheel sizes, offsets, etc. For Mk2s it's complicated further in that they really, really, need stagger between front and rear.

[Mave]

Miner49er said:

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

I'm a bit surprised, I would have expected the manufacturer to keep the suspension geometry the same irrespective of wheel size. Eg on the e46 series, the non staggered wheels all have 46-47mm offset, whether you're fitting 15" or 18" wheels...

[Mave]

hotrat said:

if i want to dish it out 10mm from standard then i will take 10mm off the standard offset when i order the wheels, if you know what i mean. asking more than telling lol

Just remember that you'll be changing the effective track, so make sure you're happy with any handling changes.

[andyiley]

Mave said:

Miner49er said:

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

I'm a bit surprised, I would have expected the manufacturer to keep the suspension geometry the same irrespective of wheel size. Eg on the e46 series, the non staggered wheels all have 46-47mm offset, whether you're fitting 15" or 18" wheels...

FWIW I agree, I could see the offset change with wheel width but not rim size.

[Miner49er]

Mave said:

Miner49er said:

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

I'm a bit surprised, I would have expected the manufacturer to keep the suspension geometry the same irrespective of wheel size. Eg on the e46 series, the non staggered wheels all have 46-47mm offset, whether you're fitting 15" or 18" wheels...

Yes, and that’s why a range of cars have different wheel offsets. Manufacturer’s will increase track on their sportier models to give a more purposeful look. They’ll do this cheaply by simply designing wheels with a smaller offset. Bottom of the range cars tend to have wheels with greater offsets than their sportier counterparts. E46’s have a range of 36 to 47.

[Miner49er]

andyiley said:

Mave said:

Miner49er said:

A bottom of the range model on steel wheels will have a different offset to the top of the range on optional 19's... Hence the two figures.

I'm a bit surprised, I would have expected the manufacturer to keep the suspension geometry the same irrespective of wheel size. Eg on the e46 series, the non staggered wheels all have 46-47mm offset, whether you're fitting 15" or 18" wheels...

FWIW I agree, I could see the offset change with wheel width but not rim size.

By rim size, I assume you mean wheel diameter? If that’s the case, I made reference to 19 inch wheels as they’ll inevitably be wider than the bog standard model’s 16 inch wheels. Apologies, I thought that was obvious.

[Mave]

Miner49er said:

Manufacturer’s will increase track on their sportier models to give a more purposeful look. They’ll do this cheaply by simply designing wheels with a smaller offset. Bottom of the range cars tend to have wheels with greater offsets than their sportier counterparts. E46’s have a range of 36 to 47.

But the e46 alloys all have the same offset from 15" skinnies up to 18" wide rims, that was my point. To make the car look sportier they don't change the offset, they change the wheel width. If you try to make an e46 look sportier by reducing the offset, it just tramlines everywhere...

[Miner49er]

Erm... Offsets are measured to the centreline of the wheel, so in nearly all cases, different width wheels naturally have different offsets...

Edit: E46 wheels do not all have the same offset.

[sausage76]

Offset is determined by width of rim not diameter.

Offset will change depending on spec of wheel and car and can also change in a model range due to this.

All makes or car have a standard offset that the manufacturer recommends, that why for example on an E36 you will get a range. Also will depend on size and width of arches and what can physically fit in that space.

But saying that any offset wheel can be made to fit any car just depends on how much work you want to do.

The offset is usually stamped in the rear of the rim. Or just use google type in car make and offset you'll find loads of info on your car.

[Mave]

Miner49er said:

Erm... Offsets are measured to the centreline of the wheel, so in nearly all cases, different width wheels naturally have different offsets....

Erm... The non-m alloy e46 wheels going from what, 7 to 8.5 inches wide keep the same offset by adding width symmetrically, not through offset. If it was added symmetrically, you'd get ~38mm offset variation!