Everybody says 19" are uncomfortable

[MrPT]

Nice - I'm assuming BBS stamp them somewhere? Mine did come with BBS centre caps (that I have changed)!

Yep. "BMW" on the front of the hub, inside the M badge, and "BBS" on the back of the spokes.

 

[z4pilot]

If you use willtheyfit.com you can have a play around with the various widths and profiles to see what the impact on diameter will be. Handily it also tells you what the impact on your speedo will be - too extreme an increase in diameter will throw your speedo out by a few miles per hour.

Yeh I use that all the time - but it doesn't tell me what I was actually trying to find out with this post - whether it will fit your arches or if it'll rub.

On a non M/// the main risk of rubbing is at the front. If you go much wider than 15mm greater offset than the standard 8j wheel, you run the risk of rubbing over sharp compressions, especially if lowered or your suspension is tired. You can reduce the risk by playing around with the tyre width - drop down to a 215 section tyre for instance. If you go with an 8.5j width wheel you need to adjust the allowable offset for the greater width. At the back, most people aim for a 20mm increase as this more or less gives the best visual improvement, although you can get away with wider, especially if you run extra camber to tuck the wheels in a little at the top. Again, this is an absolute measurement using the standard wheel sizes as a baseline - adjust as necessary with wider wheels and offsets to give the same overall track increase. Don't forget that when people quote M/// numbers at you that they won't automatically work on a non M/// - they have different axles and so their starting offsets are different - the offsets needed to bring M/// wheels flush will be too extreme for a non M.

 

[MrPT]

^ good advice. It’s definitely worth having a play with a tyre fitment calculator so you know where you’ll end up visually compared to your current setup.

I went with 12mm front and 15mm rear spacers with my non-M roadster, which had the common wheel sizes of 18 x 8J ET47 and 18 x 8.5J ET50. As z4pilot says, +15mm and +20mm vs stock is probably the most popular, but can look a little rollerskatey if you don’t also lower the car.

OP - as above, the CSL sizes Mr Tidy and I have been talking about won’t be suitable for a non-M. The below are very popular reps (for example) with offsets that work well on a non-M. With 225/35/19 front and 255/35/19 rears they should also be quite comfortable.

https://www.bmautosport.co.uk/showroom/product_info.php/new-riva-dtm-csl-alloy-wheels-silver-deep-concave-wide-rear-p-422

 

[Bufort]

I went with 12mm front and 15mm rear spacers with my non-M roadster, which had the common wheel sizes of 18 x 8J ET47 and 18 x 8.5J ET50. As z4pilot says, +15mm and +20mm vs stock is probably the most popular, but can look a little rollerskatey if you don’t also lower the car.

I'm not planning on trying to get it to stick out more; I'll just use whatever it takes to make a 19" wheel with a comfortable tyre fit under my arches with no rubbing at all.

Thanks for all the help - and to reiterate the answer for any future viewers of this thread - YES, you can fit 19" wheels with the same profile tyres as 18" wheels for comfort.

 

[tomscott]

I need some new tyres for my CSL this summer and wondering what to go for. The Mich are the obv choice but they are a decent premium over all the others.

Stupid question what's the benefit of reducing the tyre width on the back from 265 to 255? Do you not loose a bit of rubber to the road but also does it not stretch the tyre giving less rim protection?

 

[mr wilks]

I need some new tyres for my CSL this summer and wondering what to go for. The Mich are the obv choice but they are a decent premium over all the others.

Stupid question what's the benefit of reducing the tyre width on the back from 265 to 255? Do you not loose a bit of rubber to the road but also does it not stretch the tyre giving less rim protection?

Ive just bought a set of Dunlop SportMaxx RT2 for my CSLs , been trialing them out on the 224s for the last month or so
Can't fault them & around £400 for the set with 255 35 19 rears , ive always preferred this fitment for the added comfort plus dependent on brand there is no stretch to the sidewall & if you do some study changing from 265 30 19 to 255 35 19 on a 9.5j doesn't mean you lose contact patch of tyre on tarmac . also worth noting this is the size the E46 M3 had on its rear CSLs

 

[mr wilks]

Thanks for all the help - and to reiterate the answer for any future viewers of this thread - YES, you can fit 19" wheels with the same profile tyres as 18" wheels for comfort.

Its not in question that you can fit the tyres to the wheels , whether they will then work on your car is a totally different matter .
There are many other deciding factors to consider such as wheel width , offset , tyre brand ( & if new with full 8mm tread or partworn )
Suspension set up also needs considering & don't forget you will be upping considerably the rotational mass so the car may well feel different to drive .
Lots to consider

 

[tomscott]

I need some new tyres for my CSL this summer and wondering what to go for. The Mich are the obv choice but they are a decent premium over all the others.

Stupid question what's the benefit of reducing the tyre width on the back from 265 to 255? Do you not loose a bit of rubber to the road but also does it not stretch the tyre giving less rim protection?

Ive just bought a set of Dunlop SportMaxx RT2 for my CSLs , been trialing them out on the 224s for the last month or so
Can't fault them & around £400 for the set with 255 35 19 rears , ive always preferred this fitment for the added comfort plus dependent on brand there is no stretch to the sidewall & if you do some study changing from 265 30 19 to 255 35 19 on a 9.5j doesn't mean you lose contact patch of tyre on tarmac . also worth noting this is the size the E46 M3 had on its rear CSLs

That’s great value! Almost have the price cheaper of the pilots!

From a size point of view the standard 19” M3 and the M3 CS wheels were 255 but the CSL was 265 although they all run 19x9.5

https://bimmertips.com/oem-bmw-e46-m3-wheel-options-specs/

 

[Bufort]

Stupid question what's the benefit of reducing the tyre width on the back from 265 to 255? Do you not loose a bit of rubber to the road but also does it not stretch the tyre giving less rim protection?

If you do some study changing from 265 30 19 to 255 35 19 on a 9.5j doesn't mean you lose contact patch of tyre on tarmac.

How would that not mean you lose contact patch? If you go from a 265 to a 185, you lose 80mm of the contact patch, if you go to a 255, you don't lose much, 10mm, but you're still losing some. Unless you're saying the actual tread width on a 255 and a 265 are the same size, and its just the overall width that changes (the bulge at the sides), but I don't think thats the case.

The minute bit of 'stretch' that you're getting by fitting a narrower tyre to the same size rim, and the inconsequential amount of the radiused corner that will roll from the side to the top of tyre will be vary between every tyre made and therefore cannot be taken into consideration if you're generalising.

 

[z4pilot]

Stupid question what's the benefit of reducing the tyre width on the back from 265 to 255? Do you not loose a bit of rubber to the road but also does it not stretch the tyre giving less rim protection?

If you do some study changing from 265 30 19 to 255 35 19 on a 9.5j doesn't mean you lose contact patch of tyre on tarmac.

How would that not mean you lose contact patch? If you go from a 265 to a 185, you lose 80mm of the contact patch, if you go to a 255, you don't lose much, 10mm, but you're still losing some. Unless you're saying the actual tread width on a 255 and a 265 are the same size, and its just the overall width that changes (the bulge at the sides), but I don't think thats the case.

The minute bit of 'stretch' that you're getting by fitting a narrower tyre to the same size rim, and the inconsequential amount of the radiused corner that will roll from the side to the top of tyre will be vary between every tyre made and therefore cannot be taken into consideration if you're generalising.

You're assuming that the contact patch is the full width of the tyre - that's probably not the case, I'm surmising that it will be central to the contact point with the road and it's area will be affected by variables such as tyre width, but also suspension geometry, tyre inflation, tread depth (there's a reason why racing tyres are slick) etc. The 10mm difference between the width of a 255 and 265 section tyre probably doesn't amount to a huge difference in contact patch - and in any case, the opinion has been expressed on here a few times that the non-M Z4 is over-tyred, so in real world condintions, you'll never notice a lack of grip, but will notice an increase in comfort.

 

[Bufort]

You're assuming that the contact patch is the full width of the tyre - that's probably not the case, I'm surmising that it will be central to the contact point with the road and it's area will be affected by variables such as tyre width, but also suspension geometry, tyre inflation, tread depth (there's a reason why racing tyres are slick) etc. The 10mm difference between the width of a 255 and 265 section tyre probably doesn't amount to a huge difference in contact patch - and in any case, the opinion has been expressed on here a few times that the non-M Z4 is over-tyred, so in real world condintions, you'll never notice a lack of grip, but will notice an increase in comfort.

OK, so you're actually agreeing with me that yes it does technically reduce the contact area, but it is so small and affected by so many other variables that it makes bugger all difference. I wasn't assuming the contact patch is the overall width, as I was pointing out that the bulge of the tyre at the sides will be affected by the ratio between the tyre width and rim width.

 

[mr wilks]

You're assuming that the contact patch is the full width of the tyre - that's probably not the case, I'm surmising that it will be central to the contact point with the road and it's area will be affected by variables such as tyre width, but also suspension geometry, tyre inflation, tread depth (there's a reason why racing tyres are slick) etc. The 10mm difference between the width of a 255 and 265 section tyre probably doesn't amount to a huge difference in contact patch - and in any case, the opinion has been expressed on here a few times that the non-M Z4 is over-tyred, so in real world condintions, you'll never notice a lack of grip, but will notice an increase in comfort.

OK, so you're actually agreeing with me that yes it does technically reduce the contact area, but it is so small and affected by so many other variables that it makes bugger all difference. I wasn't assuming the contact patch is the overall width, as I was pointing out that the bulge of the tyre at the sides will be affected by the ratio between the tyre width and rim width.

Just before you head off into the sunset whistling a happy tune its not always a cert that going a size wider on tyres would always increase contact patch & vice versa :wink:
Worth a read if its a topic that interests you https://www.roadandtrack.com/car-culture/videos/a4835/thing-you-thought-you-knew-points-of-contact-tire-patches/

 

[z4pilot]

You're assuming that the contact patch is the full width of the tyre - that's probably not the case, I'm surmising that it will be central to the contact point with the road and it's area will be affected by variables such as tyre width, but also suspension geometry, tyre inflation, tread depth (there's a reason why racing tyres are slick) etc. The 10mm difference between the width of a 255 and 265 section tyre probably doesn't amount to a huge difference in contact patch - and in any case, the opinion has been expressed on here a few times that the non-M Z4 is over-tyred, so in real world condintions, you'll never notice a lack of grip, but will notice an increase in comfort.

OK, so you're actually agreeing with me that yes it does technically reduce the contact area, but it is so small and affected by so many other variables that it makes bugger all difference. I wasn't assuming the contact patch is the overall width, as I was pointing out that the bulge of the tyre at the sides will be affected by the ratio between the tyre width and rim width.

Nope, wasn't agreeing with you at all. Going from a 265 to 185 tyre won't lose you 80mm of contact patch as you stated, and in any case the contact patch is measured in area, because it's a function of width and length. You seem pretty confident that you've got all this sussed, so crack on and let us know what you've bought.

 

[Lazza]

Tyre contact patch area is affected more by tyre pressure. Changing width only really affects contact patch shape. If you fit narrower tyres the contact patch will of course be narrower but will also be longer assuming the same tyre type and pressure is used.

Personally I’m using 235/35/19 265/30/19. That gives a touch taller tyres than standard improving ride and protecting the alloys and also giving a bit more rim protection.

 

[Bufort]

You're assuming that the contact patch is the full width of the tyre - that's probably not the case, I'm surmising that it will be central to the contact point with the road and it's area will be affected by variables such as tyre width, but also suspension geometry, tyre inflation, tread depth (there's a reason why racing tyres are slick) etc. The 10mm difference between the width of a 255 and 265 section tyre probably doesn't amount to a huge difference in contact patch - and in any case, the opinion has been expressed on here a few times that the non-M Z4 is over-tyred, so in real world condintions, you'll never notice a lack of grip, but will notice an increase in comfort.

OK, so you're actually agreeing with me that yes it does technically reduce the contact area, but it is so small and affected by so many other variables that it makes bugger all difference. I wasn't assuming the contact patch is the overall width, as I was pointing out that the bulge of the tyre at the sides will be affected by the ratio between the tyre width and rim width.

Nope, wasn't agreeing with you at all. Going from a 265 to 185 tyre won't lose you 80mm of contact patch as you stated, and in any case the contact patch is measured in area, because it's a function of width and length. You seem pretty confident that you've got all this sussed, so crack on and let us know what you've bought.

I know that a contact patch is an area defined by two dimensions, I was just simplifying it, but if I must: 255x150=38,250mm2 & 185x150=27,750mm2. So all other factors being the same, there will be a smaller contact patch. If I'm wrong, why don't you just explain why?

And I don't see what the reason for slick racing tyres has to do with this as thats because it will get the most contact for a given size, and the lack of tread is for dry tracks whereas having tread is to prevent aquaplaning, nothing to do with the width of the tyre.

 

[Bufort]

Tyre contact patch area is affected more by tyre pressure. Changing width only really affects contact patch shape. If you fit narrower tyres the contact patch will of course be narrower but will also be longer assuming the same tyre type and pressure is used.

Personally I’m using 235/35/19 265/30/19. That gives a touch taller tyres than standard improving ride and protecting the alloys and also giving a bit more rim protection.

Why does the width being narrower increase the length of the contact patch? Actually I just realised that the decrease in width would increase the pressure from the load over the smaller area, therefore lengthen the contact patch. But... tyre pressures would be compensated anyway.

 

[z4pilot]

OK, so you're actually agreeing with me that yes it does technically reduce the contact area, but it is so small and affected by so many other variables that it makes bugger all difference. I wasn't assuming the contact patch is the overall width, as I was pointing out that the bulge of the tyre at the sides will be affected by the ratio between the tyre width and rim width.

Nope, wasn't agreeing with you at all. Going from a 265 to 185 tyre won't lose you 80mm of contact patch as you stated, and in any case the contact patch is measured in area, because it's a function of width and length. You seem pretty confident that you've got all this sussed, so crack on and let us know what you've bought.

I know that a contact patch is an area defined by two dimensions, I was just simplifying it, but if I must: 255x150=38,250mm2 & 185x150=27,750mm2. So all other factors being the same, there will be a smaller contact patch. If I'm wrong, why don't you just explain why?

And I don't see what the reason for slick racing tyres has to do with this as thats because it will get the most contact for a given size, and the lack of tread is for dry tracks whereas having tread is to prevent aquaplaning, nothing to do with the width of the tyre.

Not sure why someone would ask a question and then try and prove everyone who offered advice wrong? I'm very happy with my choice of wheels and tyres - hope you will be with yours. Good luck.

 

[True-Blue]

Nope, wasn't agreeing with you at all. Going from a 265 to 185 tyre won't lose you 80mm of contact patch as you stated, and in any case the contact patch is measured in area, because it's a function of width and length. You seem pretty confident that you've got all this sussed, so crack on and let us know what you've bought.

I know that a contact patch is an area defined by two dimensions, I was just simplifying it, but if I must: 255x150=38,250mm2 & 185x150=27,750mm2. So all other factors being the same, there will be a smaller contact patch. If I'm wrong, why don't you just explain why?

And I don't see what the reason for slick racing tyres has to do with this as thats because it will get the most contact for a given size, and the lack of tread is for dry tracks whereas having tread is to prevent aquaplaning, nothing to do with the width of the tyre.

Not sure why someone would ask a question and then try and prove everyone who offered advice wrong? I'm very happy with my choice of wheels and tyres - hope you will be with yours. Good luck.

Spot on, and to state the obvious ‘everybody says 19’’ are uncomfortable’ is blatantly not true... many on here more than happy on 19’s with the right tires!

 

[AnilS]

I've just put 19s on mine, with 235 (F) and 255 (R).

These are Falken FK510 that are meant to be reasonably comfortable.

My 18s had new Vredestien Vorti, 225 (F) and 255 (R).

Both are better than the run flats but there is an added element of harshness on the 19s.

I don't think it's the tyres, just the alloys as the tyres profile remains the same.

Entirely liveable with though.

 

[AnilS]

19s.