Alloys 17”

dva99999

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I’ve been looking in the BMW owners manual as I’m looking to upgrade my alloys from 16” to 17” and I’m confused.
My 2.8 is a wide body.
It’s states that of the 17” the spec is 7.5Jx17 with 225/45 ZR17 tyres for the front and 8.5Jx17 with 245/40 ZR17 for the rear. This is for summer tyres

However it also states for winter tyres you can have 7.5Jx17 with 225/45 R 17 91 Q......

And 8Jx17 but does not mention which tyres. I’m assuming they are the same as the above for winter tyres I could be wrong.

How important is this as every time I look for alloys they are all the same spec. I’ve only just realised what a ‘staggered’ set up is and wondered whether this is important for this particular car. BMW seem to recommend a staggered set up in summer but not in winter.
How does a staggered set up affect the handling of the car and do most people just stick with the same set up all round?
I’ve drawn mostly blanks when asking this question so my guess is that it’s not an easily answered question.
Thanks
 

Rudyrov

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Not sure about Z3 owners, but in the Seattle area most guys have a separate set of rims with winter tires ready for winter.
Usually they are not very attractive rims either.
 

IainP

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You're quite correct, it is Very complicated.
Short Simplified Version:
In the dry, more rubber, more grip.
In the wet, less rubber, more grip.
In snow, a lot less rubber, and as many edges as possible, with rubber as soft as possible, more grip.

Slightly more complicated version.
Staggered, wider rear, gives a slightly understeer setup with a higher level of rear grip. In The Dry. Gives a good level of confidence and is easy for most drivers to control. In the wet, you have less rear grip, depending on the type and pattern of tyre, and a whole load of other factors I won't go into.
Snow, whole different game. You want as much ground pressure as possible, Force = Mass X Area. The people who say you should let air out of your tyres for more grip.. . . Complete Idiots. Don't do it. It's actually Really Dangerous with modern tyres, you'll damage them internally. And have less grip, not more.
You need a tyre that conforms to the surface as much as possible, so, higher profile and as soft a rubber as possible, within reason. You need as many biting edges as you can get. A summer tyre may have as few as 8 horizontal edges in the contact patch, the piece of tyre in contact with the ground. A snow tyre, whilst being narrower, may have close to a hundred. Really.
 

dva99999

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You're quite correct, it is Very complicated.
Short Simplified Version:
In the dry, more rubber, more grip.
In the wet, less rubber, more grip.
In snow, a lot less rubber, and as many edges as possible, with rubber as soft as possible, more grip.

Slightly more complicated version.
Staggered, wider rear, gives a slightly understeer setup with a higher level of rear grip. In The Dry. Gives a good level of confidence and is easy for most drivers to control. In the wet, you have less rear grip, depending on the type and pattern of tyre, and a whole load of other factors I won't go into.
Snow, whole different game. You want as much ground pressure as possible, Force = Mass X Area. The people who say you should let air out of your tyres for more grip.. . . Complete Idiots. Don't do it. It's actually Really Dangerous with modern tyres, you'll damage them internally. And have less grip, not more.
You need a tyre that conforms to the surface as much as possible, so, higher profile and as soft a rubber as possible, within reason. You need as many biting edges as you can get. A summer tyre may have as few as 8 horizontal edges in the contact patch, the piece of tyre in contact with the ground. A snow tyre, whilst being narrower, may have close to a hundred. Really.
Fantastic write up....so how does that translate to the alloys and tyres. 17” is definitely what I’m after. And is there a good all round tyre say from Michelin?
 

IainP

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If you want outright 'looks', staggered setup with the recommended tyre sizes. Be aware that the wider rears can be more prone to cracks in the rim depending on the make. My son, who's cars are heavily stanced, has warned me off Dare alloys for instance.
I'd look at a set of BMW alloys, style 32, 42, cup or M sport, and have them refurbished if necessary.
If you want simplicity, go for a square setup, all the alloys and tyres the same size. It would be my preference, no discernable difference in handling except on a track. More importantly, you have the option of rotation if you're wearing one end out faster. Should probably be slightly cheaper too.
I live in the land of rain so my tyre recommendation isn't much use.
If you pop over to www.camskill.co.uk and plug in the recommended tyre size, you can compare tread patterns/use/noise, etc. to whatever the weather is you do most of the driving in.
If you're keeping the 16's, I can recommend these, I run the clio daily 130 miles a day up down from Perth/Glasgow on them every winter
965714251.jpg
Kingpin Weatherspeed retread, ran my wife's 1 series on them for years, her current car would have been on them too but they don't come in 17". The snow tyres I ended up with are quieter but not as grippy. Terrifying levels of grip. 50mph on 4" of snow, piece of p***.
 

dva99999

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If you want outright 'looks', staggered setup with the recommended tyre sizes. Be aware that the wider rears can be more prone to cracks in the rim depending on the make. My son, who's cars are heavily stanced, has warned me off Dare alloys for instance.
I'd look at a set of BMW alloys, style 32, 42, cup or M sport, and have them refurbished if necessary.
If you want simplicity, go for a square setup, all the alloys and tyres the same size. It would be my preference, no discernable difference in handling except on a track. More importantly, you have the option of rotation if you're wearing one end out faster. Should probably be slightly cheaper too.
I live in the land of rain so my tyre recommendation isn't much use.
If you pop over to www.camskill.co.uk and plug in the recommended tyre size, you can compare tread patterns/use/noise, etc. to whatever the weather is you do most of the driving in.
If you're keeping the 16's, I can recommend these, I run the clio daily 130 miles a day up down from Perth/Glasgow on them every winter
View attachment 100393
Kingpin Weatherspeed retread, ran my wife's 1 series on them for years, her current car would have been on them too but they don't come in 17". The snow tyres I ended up with are quieter but not as grippy. Terrifying levels of grip. 50mph on 4" of snow, piece of p***.
Actually that’s a really good point....I don’t plan on doing track days but I do rotate them. I won’t keep the 16” purely because with the wide bodied stance I think 17” will look better I’m hoping with no major difference in the handling. I’m currently using Conti winter tyres on the front the rears I can’t remember but they’re not a good brand and need changing. I’ve heard good things about Falkens.
 

IainP

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The smaller profile sharpens the handling
The technical term is "sharper turn in due to reduced slip angle", if you want to baffle folk in the pub.
I've run through a couple of sets of Falken, liked them a lot. I quite like Hankook and Avon too. My wife absolutely loved our 3 series once I swapped the 17" runflats for Avons.
 

Scooblitz

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Currently selling a set of 17" wheels that fit Z3. Almost brand new. Check out the for sale thread if you fancy some nice 5 spoke wheels. 8J square.As for wheels, this is a bit of a rabbit hole im in at the moment. You can for sure run several different wheel combinations on these Z's and it really is all down to taste.

In terms of Z3's, front fitment is 3 series and the rear is 1,3,5 series+. You can pretty much go to town on the rear as your 2.8i has such a wide bum. Even with the fronts, if there is a will there is a way: tyre stretching or even camber plates to run only 1-2 degrees of camber to get enough tyre tread under the arches.

Fronts: 17X7.5J or 17x8J - Tyres, no more than 225/45/17 - Offset for 8j or 8" wheel. I would say offset of ET30+ is fine. You can run a lower offset if you have 7.5" wheels. Perhaps ET25+ could work.

Rear- Rears can even take an 11" wheel. Massive. More of a Porsche style fit but for me it makes the car look awesome, especially the 2.8's.

Staggered fitment does come out of the factory too. Porsche 911s have 7.5" front wheels and 9.5" rears on the models of the same period as the Z3. If you want the Z3 to look sporty, take a look at the Z3m cars as your car can fit similar width wheels too. Second time of posted this photo on these boards in a week but im obssessed. 17" Rondell 0058 rear is 10 inch wheel. There are fitments out there that will work fot the z3's incuding getting some 'lip', as pictured. A 17" 8J et35 is available for the fronts. Set for sale in Aberdeenshire at the moment, but i ain't got the money.https://www.ebay.co.uk/itm/BMW-Rond...460739?hash=item2ce92ada43:g:zr8AAOSwcBRbwxNQ
wheelporn.jpg
 
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