Offset query - max/min possible difference from standard?

[a11y]

Hi

I'm only starting to understand wheel offset with the help of this calculator and now understand what a bigger or smaller offset will do the wheel position. I don't, however, know what offsets will fit on a standard (non-M) Z4 with 18"s...

I know the standard offset is: front 18x8.0 ET47, rear 18x8.5 ET50.

What sort of other offsets will work on a Z4? i.e. what's the maximum distance that wheels can be moved OUT on a Z4? Obviously I don't want to end up with a narrower track, so wheels with a bigger offset than standard is no good.

Can anyone advise on what minimum offset will fit on a Z4 with no rubbing problems, etc.? (e.g. would a wheel with ET34 be OK on the front - 13mm further out in the wheelarch).

Any help much appreciated. I've had a good search but no definative answer came up!
Ally

 

[Mr Whippy]

I'm not sure on the ranges to which you can go, but it's best to stay as close to OEM track width as possible.

Going smaller will reduce steering weight, going wider will increase steering weight.

Adding front track width will tend to increase oversteer, reducing will add understeer.

Adding rear track will tend to understeer, reducing will oversteer.


On most cars you will easily notice having 10mm less or more track width in the weighting of the steering.

Dave

 

[a11y]

Cheers, I don't particularly want to change the track width, but it opens up more options for alloys if you can use a different offset obviously.

I started looking at that website selling 2nd hand BMW alloys after seeing it in a thread of yours earlier - that's what prompted this, you've got me thinking . There's some alloys on there that are half-tempting, but they're 8.0 ET34 and 8.5 ET37 so would increase the track front and back by 26mm in total (13mm each side). Sounds quite a lot to me, hence am unsure if that much offset would "work" or not. I'm not set on the alloy design either, other than them NOT being corroded 108s...

IMO a bit more steering weight wouldn't go amiss in the Z4 - I always hit the Sport button now everytime purely for that reason (it feels heavier to me with Sport engaged).


Can anyone add their experiences about wheels with bigger offsets rubbing, and effects on handling, etc, on a non-M Z4?

Cheers
Ally

 

[Mr Whippy]

Ally, I've had a quote for 4 x brand new Ellipsoids, bolts and centre caps, with FK452 Falkens fitted, for £1255 delivered from M Style.

Sounds alot, it is quite alot actually, but if you were tempted by Ellipsoids then that is a good deal for absolutely flawless new wheels (don't drive into kerbs) and then sell the 108's for maybe £500!? New wheels and tyres for maybe £750 in the end...


Just so you know, as thats what I may end up doing as I'm not happy with my 108's (they work, most people don't notice/care, but I do), don't mind the 107's, and know that in the longer term the 107's will stay nice and from what I'm starting to see, are actually the rarer wheel!


PS, just had a look at your pics again, and your 108's look in very good condition. It's only really the nearside rear which often gets caught by lady drivers that is a bit kerbed. I'd not look for anything else because of their condition, but if you just want a change then maybe so, as you will get a good price for a set in that condition I think.

Thanks

Dave

 

[a11y]

Dave, thanks - that's good to know but it is a lot of £££!!! I'm in a similar frame of mind to you, I think. I love the 108 design and think it suits the Z4 very well, but mine are badly corroded and it's the hassle of keeping them corrosion-free in future if I choose to get them refurbed. That's a worry I'd lose if I changed for a different alloy, e.g. the 107s. I wasn't initially a big fan of the 107s but they've grown on me - wheel design wasn't something I worried about when I bought my Z4 (anything in 18" was fine by me).

I've already bought a full set of FK452s though and I'm trying to decide if it's better buying different alloys and fit the tyres to them, or just fit them to my current 108s...

I'll probably just get my 108s powdercoated and solve the corrosion issue once and for all, but that involves me splitting the rims myself and TBH I'm scared of attempting it . It would only cost me <£200 for a full powdercoating though, so is the cheapest option at the expense of the best possible finish.

Ally

 

[Mr Whippy]

I'll probably just get my 108s powdercoated and solve the corrosion issue once and for all, but that involves me splitting the rims myself and TBH I'm scared of attempting it . It would only cost me <£200 for a full powdercoating though, so is the cheapest option at the expense of the best possible finish.

Ally

As said, I think your wheels look pretty good, but photos can hide alot.

Mine were bloody terrible full stop. The 'good recondition' as the dealer said, was so poor to the level that on one of the spokes where it overlays the outside of the rim with a gap underneath, they had masked OVER it, and sprayed their single pass silver ontop of the inner part and generally done a bad mask into the gap between inner/outer
Had I known their 'good recondition' was actually going to be shocking I'd have asked for another £100 off and a left them as they were... so honestly, yours are not that bad... from the ones I've had a nosey at elsewhere too yours are actually getting on for mint as 108's go


Powdercoating is a good solution for the outers, but in my experience isn't as smooth and as nice a finish as proper two pack paints, nor much cheaper.

107's are the future for Titanium Silver owners I think

Considering their rarity, ability to stay looking good if you don't drive up kerbs, and their 'flame' looks, I rekon they will add value to Z4's down the line


Dave

 

[a11y]

Sounds like yours are far worse than mine TBH. Mine at least haven't been tampered with in terms of a dodgy refurb. I used the wheel condition as a bargaining tool when I bought my Z4 and got £200 off

It's really just the insides of my alloys that are gubbed - luckily the outside edge is free of corrosion on all 4 wheels, although the passenger ones are curbed to buggery by the previous owner's wife (his words, not mine!). The lacquer's started pealing off on them all and it's probably a matter of time before the outers are affected too. TBH it's just me being fussy and I can easily live with it until I decide, although I'll have to fit my new tyres soon before I become illegal...

Argh don't say that about the 107s or you'll convince me I need a set


If anyone has info/advice on what wheel offsets fit, post up anyway, but at the moment it's still between refurbing my 108s or a set of (same offset) 107s...

 

[Mr Whippy]

TBH it's just me being fussy and I can easily live with it until I decide, although I'll have to fit my new tyres soon before I become illegal...

Exactly the same situation here really.

The cheap Michelin PS2 ZP offer runs out on Sunday, which is 20% off on a set of four, which makes them really cheap considering.

Might just get them as it keeps me legal and they are great tyres to enjoy the car with, then worry about the wheels later. After a few days of brake dust and road grime you can't tell they are badly reconditioned anyway

Dave

 

[a11y]

Oh well, that's that decided then. I've booked a tyre fitter to visit me tomorrow night to fit my FK452s to my 108s! I'm keeping these alloys and will deal with the corrosion at a later date - they're not a priority and I can live with them for the moment.

Good news is that the powdercoater I use can remove/refit non-RFTs as part of his price for refurbing my wheels, but his tyre machine can't cope with RFTs, so that helps things a bit later on. Gives me time to build up the confidence to split my alloys myself

As much as I like other designs, I just think the 108s are the best on a silver Z4

 

[Mr Whippy]

I decided the same, just going to ring and check non-rft with the insurer today, and will just get FK452's put on hopefully at the weekend.

I will definately be keeping an eye out for some Ellipsoids down the line though, as the 108's are just a liability longer term for going bad again if I get them sorted...

Dave