[AlRex]

So my tyres are getting close especially the rears and in need or replacement.

Only thing is I can’t seem to find the 255 35 19 star marked anywhere? Has any one any ideas where I could get some or should I settle for the ordinary 4s?

Also considering the normal 4 as I’m on 20-30k a year, was reading these may last a little longer?

[Ennoch]

Well in the next half hour I will have decided whether to go for PS4S go-flats or Pirelli PZ4 * RFT's (which do seem to get some pretty decent reviews). That and they have the security of being run flats, albeit run flats seem to have more issues than normal tyres!

Take a look at the tyre reviews recent high performance test as he puts a table in the middle of the vid - the PS4S actually has a harder rubber than the PS4 (69A vs 72A IIRC) which would lead to them lasting longer, in theory. This probably goes with them being better in the dry at the expense of wet performance when compared to the normal PS4.

As for the star marking, I asked BMW to see when they would be available in our size and apparently they'll be available to order from the suppliers from the 1st July.

[Londoner]

Welcome to the waiting room Ennoch/Alrex. I emailed Michelin a few days ago asking them this very question. The front 19s are available (albeit in limited numbers), but nothing for the rears.

Will let you know if I hear back from them.

[Londoner]

Originally Posted by Ennoch

As for the star marking, I asked BMW to see when they would be available in our size and apparently they'll be available to order from the suppliers from the 1st July.

Just seen this - you mean for our F3X 19s?

[Ennoch]

Indeed. Allegedly. They wanted to stick a set of replacement S001's on for some ridiculous amount so I asked them if they could check about sourcing * marked PS4S and that's what they came back with, albeit no price. In the end I've just taken the hit for 4x PS4S normal tyres, which means a potential risk with flats from holes in the road but it seems the non-RFT's are less likely to suffer from it so it's all relative! Black Circles came up top at £540 for four and then £20 to get them all fitted at the place round I use round the corner. I should be able to sell the nearly new front S001's for at least £100 so that should recoup a little of the cost. If the * marked ones are available next time I'll probably go for them, and if there's ever any drivetrain issue that needs warranty sorted out I'll just nick my neighbour's wheels as he's just put 4 new S001's on!

[AlRex]

I have been looking at black circles too with 15% off the PS4s at the moment.

I was quoting with fitting though as they are a bit funny round here about fitting other tyres than what they supply, the place I used to use closed down! And the other place the guys I knew moved on who were the cash in hand guys.

[Londoner]

Useful stuff, cheers Ennoch! That's a really good price as well. I'm trying to hold out for the * marked, for the warranty reasons you mention. Although looks like most seem to think that as long as they're the right size, BMW shouldn't in theory be able to pull any of that drive train/void warranty business, but I'd rather the piece of mind.

[Ennoch]

Well the tyres arrived today and I just measured them around the second band of rubber - 2058mm circumference on the rears and 2074 on the front which equates to a 0.78% difference. Given the fronts wear quicker (or at least appear to based on the rears still being good on my car vs the fronts which were replaced 5-6k ago) I'd say that is within the 1% recommendation and slightly less than the 0.83% suggested by the tyre calculators. If a driveline is that fussed by diameter then it's not fit for purpose IMO, albeit plenty of manufacturers seem to be like that. I'll measure the circumference of the tyres coming off which are star marked but I suspect the difference between nearly new fronts and worn rears is likely to be bigger!

[HighlandPete]

Originally Posted by Ennoch

Well the tyres arrived today and I just measured them around the second band of rubber - 2058mm circumference on the rears and 2074 on the front which equates to a 0.78% difference. Given the fronts wear quicker (or at least appear to based on the rears still being good on my car vs the fronts which were replaced 5-6k ago) I'd say that is within the 1% recommendation and slightly less than the 0.83% suggested by the tyre calculators. If a driveline is that fussed by diameter then it's not fit for purpose IMO, albeit plenty of manufacturers seem to be like that. I'll measure the circumference of the tyres coming off which are star marked but I suspect the difference between nearly new fronts and worn rears is likely to be bigger!

Remember that the tyre's manufactured circumference is not the measure we are really concerned about, it is the rolling circumference at 37 mph (60km/h).

What sizes? If 19" and 225/40 for the front the RC (to DIN 70020) is nominally 2022 mm. The 255/35 is 2016 mm. Just 6 mm difference in RC, at nominal dimensions.

[Ennoch]

Originally Posted by HighlandPete

Remember that the tyre's manufactured circumference is not the measure we are really concerned about, it is the rolling circumference at 37 mph (60km/h).

What sizes? If 19" and 225/40 for the front the RC (to DIN 70020) is nominally 2022 mm. The 255/35 is 2016 mm. Just 6 mm difference in RC, at nominal dimensions.

Totally, but also a bit difficult to measure the circumference with a tape measure while moving at 37mph so doing it static in my living room seemed at least a ballpark

It's the stock 19" 225/40 and 255/35. Given the fronts are slightly larger in diameter but the rears are wider I suspect the rears are more likely to balloon under rotation (I might be wrong on that, but my dim and distant past engineering degree that I've not used since leaving uni tells me it's most likely). Also interesting that both my measurements are significantly larger than the ISO. Maybe that's tread depth related, or the rubber being crushed under load? The other 'interesting' thing is that, off the car at least, the front tyres look wider relative to the rears than the OEM S001's do. If they're manufactured to BMW spec I wonder if they dropped the front size down a smidge to bring the rolling circumference into line with the rear, rather than enlarge the rear? Of course this is impossible to know for sure unless you have a set of Bridgestone spec S001's to compare directly to the BMW * spec. All idle pondering that's unlikely to find any answers, but it would be interesting to know at least.

[AlRex]

So purchasing time….. I can’t get the star marked rears.

Am I better to either

A get 2 star marked front and the ordinary rears

B get all 4 the same non star marked?

Wanted the star marked but not sure if I’m better off with them all the same so the handling is predictable?

[BBri89]

I'm by no means an authority on the subject, but if it was me, I'd go for all 4 of the same, ie non-*

At least that way the balance between the two front & rear is the same.
Whilst it probably won't be quite as dramatic, if you stick nasty budget tyres on the rear and good tyres on the front, you'd end up with lots of unpredictable oversteer and little progressiveness and control.

Plus from the comparison test, the wet grip is better with the non-* than it is with the * which for me is more important on roads.

[AlRex]

Originally Posted by BBri89

I'm by no means an authority on the subject, but if it was me, I'd go for all 4 of the same, ie non-*

At least that way the balance between the two front & rear is the same.
Whilst it probably won't be quite as dramatic, if you stick nasty budget tyres on the rear and good tyres on the front, you'd end up with lots of unpredictable oversteer and little progressiveness and control.

Plus from the comparison test, the wet grip is better with the non-* than it is with the * which for me is more important on roads.

Fair comment thanks, think this is where I was heading as well.

Yeah I noticed about the wet grip too….. it is wet in England quite a lot…..

[Dave_3]

Originally Posted by AlRex

So purchasing time….. I can’t get the star marked rears.

Am I better to either

A get 2 star marked front and the ordinary rears

B get all 4 the same non star marked?

Wanted the star marked but not sure if I’m better off with them all the same so the handling is predictable?

I am guessing your 440i is not X-Drive - in which case the * marked advantages in keeping rolling circumference as close to each other as possible across both front and rear axles fitted with staggered wheels is not so relevant to you - go B with a good brand.

D.