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Z4 M40i
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Z4 M40i
Hi all.
Please be gently on me I`ve just ordered A Z4 M40i for delivery in May.
Can anybody tell my the PCD and the centre bore Diameter.
My current car is an M340I and I`ve two set of wheels for it a set of 19 inch M898`s used for summer and set of 18inch 780 used for winter, Will either of these wheels fit?
Thanks in advance.
Mark
Please be gently on me I`ve just ordered A Z4 M40i for delivery in May.
Can anybody tell my the PCD and the centre bore Diameter.
My current car is an M340I and I`ve two set of wheels for it a set of 19 inch M898`s used for summer and set of 18inch 780 used for winter, Will either of these wheels fit?
Thanks in advance.
Mark
Current cars M340i and a Caterham 7
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Z4 M40i
Welcome…here you go..answers to the universe..tweeky687 wrote: ↑Thu Jan 23, 2025 6:46 pm Hi all.
Please be gently on me I`ve just ordered A Z4 M40i for delivery in May.
Can anybody tell my the PCD and the centre bore Diameter.
My current car is an M340I and I`ve two set of wheels for it a set of 19 inch M898`s used for summer and set of 18inch 780 used for winter, Will either of these wheels fit?
Thanks in advance.
Mark
https://www.wheel-size.com/
“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”….
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting..
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting..

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Z4 M40i
Hello and welcome, the standard winter wheel/tyre for the Z4 M40i is a square 255/40 R18 on a 18 x 8.5 alloy ET 30. I run 255/35 R19 on 19 x 8.5 with Continental AllSeason Contacts and do not have an issue with grip in everyday use when it's cold and wet or frosty, a few inches of snow is not much of a hindrance, it's always the back that gives up first and it is controllable.
If your standard winter setup is 225/45 R18 on ET25, this has a similar diameter to 255/40 R18 and the poke is 8mm less than standard, so you could get a set of 10mm spacers to bring them out a bit, the key question is traction and stopping having less contact rubber.
If your standard winter setup is 225/45 R18 on ET25, this has a similar diameter to 255/40 R18 and the poke is 8mm less than standard, so you could get a set of 10mm spacers to bring them out a bit, the key question is traction and stopping having less contact rubber.
On order Black Sapphire Z4 M40i Handschalter
Current gorgeous SFR Z4 M40i
Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si

Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si
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Z4 M40i
I got a pair of cheap winter tyres to put on S/H rims, rubber compound seems very soft so I’m not expecting long life, maybe they will do 2000 miles before I change back in March
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Z4 M40i
Got your new tyres fitted yet?
On order Black Sapphire Z4 M40i Handschalter
Current gorgeous SFR Z4 M40i
Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si

Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si
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Z4 M40i
Just fitted last Friday when returned from holidays. £665 for all four fitted, new valves not required. Haven't had the opportunity to give them a good run out yet but do seam a little quieter. Will give them a proper run over the next couple of days.
Had to enter them on the idrive manually as not recognised automatically but all seams to be working fine.
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Z4 M40i
Yep, I had to do that too, I wonder how the auto recognition works?Nanu wrote: ↑Mon Jan 27, 2025 9:05 pmJust fitted last Friday when returned from holidays. £665 for all four fitted, new valves not required. Haven't had the opportunity to give them a good run out yet but do seam a little quieter. Will give them a proper run over the next couple of days.
Had to enter them on the idrive manually as not recognised automatically but all seams to be working fine.
On order Black Sapphire Z4 M40i Handschalter
Current gorgeous SFR Z4 M40i
Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si

Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si
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Z4 M40i
Got your new tyres fitted yet?
[/quote]Just fitted last Friday when returned from holidays. £665 for all four fitted, new valves not required. Haven't had the opportunity to give them a good run out yet but do seam a little quieter. Will give them a proper run over the next couple of days.
Had to enter them on the idrive manually as not recognised automatically but all seams to be working fine.
[/quote]
Yep, I had to do that too, I wonder how the auto recognition works?
[/quote]The ride feels softer and less noise. Handling seems to be good, so far the car has gone in the direction I have pointed it which is a good sign. Confused re the pressures. One BMW site says 2.2 bar all round the car monitor recommends 2.3 bar and tyres currently 2.4 bar which the garage says is the correct pressure.
What do you run yours at?
[/quote]Just fitted last Friday when returned from holidays. £665 for all four fitted, new valves not required. Haven't had the opportunity to give them a good run out yet but do seam a little quieter. Will give them a proper run over the next couple of days.
Had to enter them on the idrive manually as not recognised automatically but all seams to be working fine.
[/quote]
Yep, I had to do that too, I wonder how the auto recognition works?
[/quote]The ride feels softer and less noise. Handling seems to be good, so far the car has gone in the direction I have pointed it which is a good sign. Confused re the pressures. One BMW site says 2.2 bar all round the car monitor recommends 2.3 bar and tyres currently 2.4 bar which the garage says is the correct pressure.
What do you run yours at?
G29 M30i M Sport San Francisco Red
Previous
E89 35is Valencia Orange
E89 28i Crimson
E89 25i White
Previous
E89 35is Valencia Orange
E89 28i Crimson
E89 25i White
- sars
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Z4 M40i
Nanu,
I think this may classify as a thread hijack
If you go to the screen where you had to configure the tyres, somewhere in there are three tyre pressure setting options, partially loaded comfort and eco and fully loaded. Each setting has different pressure settings, so dependant on temperature, comfort is 2.2 bar and eco is higher, I think 2.6 bar, mine are set at 2.3 bar. So anything between >2.2 and <2.6 bar is okay as long as they're all the same that is.
I think this may classify as a thread hijack

If you go to the screen where you had to configure the tyres, somewhere in there are three tyre pressure setting options, partially loaded comfort and eco and fully loaded. Each setting has different pressure settings, so dependant on temperature, comfort is 2.2 bar and eco is higher, I think 2.6 bar, mine are set at 2.3 bar. So anything between >2.2 and <2.6 bar is okay as long as they're all the same that is.
On order Black Sapphire Z4 M40i Handschalter
Current gorgeous SFR Z4 M40i
Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si

Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si
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Z4 M40i
So would that be spacers all round or just on the rears.sars wrote: ↑Fri Jan 24, 2025 7:45 pm Hello and welcome, the standard winter wheel/tyre for the Z4 M40i is a square 255/40 R18 on a 18 x 8.5 alloy ET 30. I run 255/35 R19 on 19 x 8.5 with Continental AllSeason Contacts and do not have an issue with grip in everyday use when it's cold and wet or frosty, a few inches of snow is not much of a hindrance, it's always the back that gives up first and it is controllable.
If your standard winter setup is 225/45 R18 on ET25, this has a similar diameter to 255/40 R18 and the poke is 8mm less than standard, so you could get a set of 10mm spacers to bring them out a bit, the key question is traction and stopping having less contact rubber.
Thanks in advance.
Current cars M340i and a Caterham 7
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- Location: East Yorkshire
Z4 M40i
Apologies, poke front is 8 mm and rear is 17 mm!, suggest you fit the rears and see how much room you have between the inside of the wheel arch to the outer edge of the tyre before buying 15.0mm spacers because 275 on a 10" wheel is slightly less stretched than a 225 on 7.5" wheel.
This explains why my rears look a little inbound compared to the normal rears which are 275/35 R19 as there is 5.0mm less poke and a smaller diameter.
On order Black Sapphire Z4 M40i Handschalter
Current gorgeous SFR Z4 M40i
Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si

Gone 2017 Iridium SL400, 2015 435d xDrive Convertible, 2012 E350 CDi Convertible, 2010 DSB Z4 sdrive30i, 2008 Audi A4 Cabriolet, 2006 Phoenix Yellow Z4 2.5Si