Star Marked Tyres on X Drive Models - Square set up.
Discussion
Riggie said:
JNW1 said:
Depends whether you believe star marked tyres are made to tighter tolerances than their non-star equivalents. From a trading standards perspective I've never been convinced they are as I can't imagine tyre manufacturers would be allowed to sell tyres which weren't to the specification stated (size, load rating, etc) and hence I think the star mark thing is over-hyped (to put it politely!).
As you say, the key with X-Drive is to make sure the rolling circumference front to rear is close enough to prevent issues with the transfer box; a square set-up obviously achieves that and with a staggered set-up it's easy enough to work out (and if you stick to BMW's recommended sizes you shouldn't have a problem anyway). But I would argue all that can be achieved with tyres that aren't star marked - providing they were the right size and load rating I would't have a problem fitting Michelin Cross Climates to my X-drive BMW even if they didn't carry a star mark.
I thought this was marketing bullst and when it came to tyre time on my X5, I went with non-star marker non-runflats and saved myself a tidy sum. A short time later, I was in Germany when I noticed a distinct whine at 60 mph. Not below or above, but at 60mph and seemed to be coming from the transfer box area.As you say, the key with X-Drive is to make sure the rolling circumference front to rear is close enough to prevent issues with the transfer box; a square set-up obviously achieves that and with a staggered set-up it's easy enough to work out (and if you stick to BMW's recommended sizes you shouldn't have a problem anyway). But I would argue all that can be achieved with tyres that aren't star marked - providing they were the right size and load rating I would't have a problem fitting Michelin Cross Climates to my X-drive BMW even if they didn't carry a star mark.
It caused me some worry and on my return to the UK I replaced all 4 with star marked tyres and guess what? The whining noise was gone. I'm as cynical as they come when it comes to what seems to be marketing hype, but in this case, I was wrong it seems.
Just out of interest how old was your X5; earlier versions of X-drive do seem more sensitive to differences in rolling circumference than later models so could that be a factor?
mekondelta said:
The only thing other than it being the star/non-star marked tyre issue is whether with the existing tyres there was a large difference (3mm+) between the front/rear set of tyres. The 4 new tyres would also have fixed this.
I agree completely with what you're saying but the way I read Riggie's post a new set of non-star marked tyres had been fitted and a problem occurred almost immediately with the transfer box; the car was then switched back to star marked tyres and the problem disappeared. So the suggestion seemed to be the issue was purely to do with the use of non-star marked tyres rather than any difference in the level of wear front to rear?JNW1 said:
mekondelta said:
The only thing other than it being the star/non-star marked tyre issue is whether with the existing tyres there was a large difference (3mm+) between the front/rear set of tyres. The 4 new tyres would also have fixed this.
I agree completely with what you're saying but the way I read Riggie's post a new set of non-star marked tyres had been fitted and a problem occurred almost immediately with the transfer box; the car was then switched back to star marked tyres and the problem disappeared. So the suggestion seemed to be the issue was purely to do with the use of non-star marked tyres rather than any difference in the level of wear front to rear?mekondelta said:
JNW1 said:
mekondelta said:
The only thing other than it being the star/non-star marked tyre issue is whether with the existing tyres there was a large difference (3mm+) between the front/rear set of tyres. The 4 new tyres would also have fixed this.
I agree completely with what you're saying but the way I read Riggie's post a new set of non-star marked tyres had been fitted and a problem occurred almost immediately with the transfer box; the car was then switched back to star marked tyres and the problem disappeared. So the suggestion seemed to be the issue was purely to do with the use of non-star marked tyres rather than any difference in the level of wear front to rear?bunchofkeys said:
Bit of a thread revival, but I've been looking around to try and find out more about these * tyres, and i think that it's necessary to have them fitted to an X drive BMW.
I recently bought a MY2010 e70, which was fitted with 3 x Continental ContiSport5 SSR and one Bridgestone Duler (on the rear), all with the * mark. The car would drove without any issues with these fitted.
With the "winter snow, beast from the east" approaching, i thought i would invest in some winter tyres.
So i bought into 4 WinterContacts TS860S, non *, and had then fitted.
Whilst driving about town, i did notice that there was a bit more of a vibration felt in the cabin, and that tight turns would (for lack of a better word) scrub the tyres on the ground.
Worst of all though was when accelerating there would be a jerk/judder throughout the car, much like slipping the clutch in a manual.
Had the X5 checked through by an BMW indy, and then measured the circumference of the front and rear tyres, which were the correct size for the 20" oem staggered alloys.
Turns out that the front were 25mm larger in circumference than the rear and the transfer case needed to adjust different size tyres, hence the jerk when pushing on.
Thankfully i still had the old tyres, so i have the local fitters swap them back over, and the jerky driving/judder/vibrations have now gone.
Seems like i've spent quite a bit on tyres that i can no longer use, which i'm a bit pissed off about (guess i will dump them on ebay), but lesson learnt.
The * mark is a necessity on at least the X drive BMW, and having non * marked tyres can be a costly mistake.
Although i doubt that any BMW, which is not an X drive, would be bothered by the * marks on the tyres, as they are only rear wheel drive.
Actually, Continental WinterContact TS 860 S SSR is very much starred. It is visible in this picture: https://i.imgur.com/igTiYcY.jpg (magnify, after "SSR")I recently bought a MY2010 e70, which was fitted with 3 x Continental ContiSport5 SSR and one Bridgestone Duler (on the rear), all with the * mark. The car would drove without any issues with these fitted.
With the "winter snow, beast from the east" approaching, i thought i would invest in some winter tyres.
So i bought into 4 WinterContacts TS860S, non *, and had then fitted.
Whilst driving about town, i did notice that there was a bit more of a vibration felt in the cabin, and that tight turns would (for lack of a better word) scrub the tyres on the ground.
Worst of all though was when accelerating there would be a jerk/judder throughout the car, much like slipping the clutch in a manual.
Had the X5 checked through by an BMW indy, and then measured the circumference of the front and rear tyres, which were the correct size for the 20" oem staggered alloys.
Turns out that the front were 25mm larger in circumference than the rear and the transfer case needed to adjust different size tyres, hence the jerk when pushing on.
Thankfully i still had the old tyres, so i have the local fitters swap them back over, and the jerky driving/judder/vibrations have now gone.
Seems like i've spent quite a bit on tyres that i can no longer use, which i'm a bit pissed off about (guess i will dump them on ebay), but lesson learnt.
The * mark is a necessity on at least the X drive BMW, and having non * marked tyres can be a costly mistake.
Although i doubt that any BMW, which is not an X drive, would be bothered by the * marks on the tyres, as they are only rear wheel drive.
Also it would be super weird if Continental, the only major German tire manufacturer didn't have the BMW star, wouldn't you agree?
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