Non runflats

raven333 · 08-16-2012, 09:30 AM

Hi ! I went to my local Costco and asked for the price for two Michelin sp tyres for the rear, insisting I did not want run-flats.
They refused to sell or fit the new rears claiming that Michelin will not let them mix runflats and non-runflats even on different axles. I said I did not want 4 tyres as the front have tons of tread left I only wanted rears....
They claimed that the handling characteristics between runflats and non-runflats was dangerous when mixed??
Anyone had this comment made to them, I have never ever heard that there is such a difference as to be dangerous???//

jparnes1 · 08-16-2012, 09:56 AM

Quote:

Originally Posted by raven333

Hi ! I went to my local Costco and asked for the price for two Michelin sp tyres for the rear, insisting I did not want run-flats.
They refused to sell or fit the new rears claiming that Michelin will not let them mix runflats and non-runflats even on different axles. I said I did not want 4 tyres as the front have tons of tread left I only wanted rears....
They claimed that the handling characteristics between runflats and non-runflats was dangerous when mixed??
Anyone had this comment made to them, I have never ever heard that there is such a difference as to be dangerous???//

In general it's not a good idea to mix different tread patterns on a car. Variations in grip can lead to unfortunate outcomes. Also, your suspension will feel weird due to the stiffness of the front tires and the relatively softer rears. If you don't like run flats just bite the bullet and buy 4 tires.

Z4@Phuket · 08-16-2012, 10:20 AM

Even in non RFT, it's not a good idea to mix front and rear with different model even in the same brand.
I only see that Pirelli offers P Zero corsa and rosso system that matches Front and rear with different thread design

Al Blue4.6l · 08-16-2012, 10:57 AM

I briefly tried that on my old z4. It completely screwed up the handling.

redhot · 08-16-2012, 11:10 AM

Yeah...mixing is not a good idea IMHO... I am looking to go the Michelin PSS route but unlike most others, I have 17inch rims and PSS do not come in a 255/40 size. So, I am thinking of 245/40 for the rears but fear that the loss in contact patch should not cause the tires to stress generating traction. I think I am OK on the weight rating and this size is approx. 2% in range from OEM size.

Whatever you decide, i'd say heed to the rest of our members and switch to non RFT... Trust me it will make your jaw hurt :d..

Vintage · 08-16-2012, 11:43 AM

it can be done obviously, just do it, but be aware that some handling issues may raise their ugly head - and then again, if you do not "push" your car, they probably will not

raven333 · 08-16-2012, 11:58 AM

I now understand many of your comments, but don't understand the tread pattern being different, surely if one puts says Michelins (run or non-runflats) on say the rear and Pirellie's on the front (again run or non-runflats) What I mean all wheels the same runflat or non runflat but different manufactures! are we saying that because the tread patterns will almost certainly be different then this will cause serious handling issues??? ( I hope I have expressed what it is I am trying to say)???

nicknaz · 08-16-2012, 04:13 PM

Quote:

Originally Posted by raven333

They claimed that the handling characteristics between runflats and non-runflats was dangerous when mixed??
Anyone had this comment made to them, I have never ever heard that there is such a difference as to be dangerous???//

Another factor is the sidewall stiffness.

It was explained to me that the sidewall stiffness contributes to the overall "wheel rate" of the suspension and mixing a tire with very stiff sidewall (RFT) and relatively soft sidewall (most non RFT) is like mixing and matching the springs in the suspension without regard for how the spring rates will work together.

wat · 08-17-2012, 04:56 AM

Git rid of your RFTs asap, you'll be glad you did. That's the first thing I did after having bought the car.

Otago · 08-17-2012, 11:25 AM

I have 18 bridgestone rft in fornt and micheline rft in rear, push to 130km no problem in handling.

dave 48 · 09-08-2012, 07:44 AM

It is true that you should not mix run flat tires and non run flats.I installed a set of bridgestone non run flats and tried the car before installing new front tires .Any speed over 40 miles an hour was scary.

raven333 · 09-08-2012, 11:06 AM

Hi! Just to confirm I WILL NOT BE MIXING runflats with non runflats. I have decided that at this time I will replace the rears only with runflats and when the fronts have worn down it will probably match the new rears I will then replace all four with non runflats.
I will probably go Goodyear's. The reason for not just going for a set of 4 non-runflats is one of cost. In the UK tyres are very expensive especially when we compare the price you pay in the States and Canada. I worked out that I would be wasting some £400 just for the privilege of running on non-runflats, I will have to be patient !!!

Vintage · 09-08-2012, 01:19 PM

I understand your decision but put 4 Michelin PSS on as soon as possible - it really will transform the car

raven333 · 09-08-2012, 01:52 PM

Hi ! thanks for the comments/advice. I did change out the runflats on my 6 series on 19" wheels and it made a major difference in ride and handling.... I will only get about 14k out of the rear bridgestones currently on my car....
I am replacing them with yes bridgestones but I have found a couple at an excellent price otherwise I would never consider them again, so eventually the move to non-runflats will be all the worthwhile....

08-16-2012, 09:30 AM	#1
raven333 Private First Class 7 Rep 175 Posts Drives: Sapphire Black 3.0siM sport Join Date: Jun 2012 Location: United Kingdom iTrader: (0)	Non runflats Hi ! I went to my local Costco and asked for the price for two Michelin sp tyres for the rear, insisting I did not want run-flats. They refused to sell or fit the new rears claiming that Michelin will not let them mix runflats and non-runflats even on different axles. I said I did not want 4 tyres as the front have tons of tread left I only wanted rears.... They claimed that the handling characteristics between runflats and non-runflats was dangerous when mixed?? Anyone had this comment made to them, I have never ever heard that there is such a difference as to be dangerous???//
	Appreciate 0 Tweet Quote

08-16-2012, 10:20 AM	#3
Z4@Phuket Lieutenant 63 Rep 432 Posts Drives: Z4 E89 Join Date: Nov 2009 Location: Bangkok, Thailand iTrader: (0) Garage List 2009 BMW Z4 [8.00] 2004 BMW 525i [0.00]	Even in non RFT, it's not a good idea to mix front and rear with different model even in the same brand. I only see that Pirelli offers P Zero corsa and rosso system that matches Front and rear with different thread design __________________
	Appreciate 0 Quote

08-16-2012, 10:57 AM	#4
Al Blue4.6l Private First Class 2 Rep 140 Posts Drives: 2009 e89 Z4 sDrive35i Join Date: Aug 2010 Location: VA iTrader: (0)	I briefly tried that on my old z4. It completely screwed up the handling.
	Appreciate 0 Quote

08-16-2012, 11:10 AM	#5
redhot Private First Class 8 Rep 138 Posts Drives: 09 Z4 sDrive35i Join Date: Feb 2012 Location: Chandler iTrader: (0)	Yeah...mixing is not a good idea IMHO... I am looking to go the Michelin PSS route but unlike most others, I have 17inch rims and PSS do not come in a 255/40 size. So, I am thinking of 245/40 for the rears but fear that the loss in contact patch should not cause the tires to stress generating traction. I think I am OK on the weight rating and this size is approx. 2% in range from OEM size. Whatever you decide, i'd say heed to the rest of our members and switch to non RFT... Trust me it will make your jaw hurt :d.. __________________ 09 Z4 35i
	Appreciate 0 Quote

08-16-2012, 11:43 AM	#6
Vintage Colonel 378 Rep 2,588 Posts Drives: BMW G80 (MT), 718 Spyder Join Date: Aug 2009 Location: Austin, Texas iTrader: (0)	it can be done obviously, just do it, but be aware that some handling issues may raise their ugly head - and then again, if you do not "push" your car, they probably will not
	Appreciate 0 Quote

08-16-2012, 11:58 AM	#7
raven333 Private First Class 7 Rep 175 Posts Drives: Sapphire Black 3.0siM sport Join Date: Jun 2012 Location: United Kingdom iTrader: (0)	I now understand many of your comments, but don't understand the tread pattern being different, surely if one puts says Michelins (run or non-runflats) on say the rear and Pirellie's on the front (again run or non-runflats) What I mean all wheels the same runflat or non runflat but different manufactures! are we saying that because the tread patterns will almost certainly be different then this will cause serious handling issues??? ( I hope I have expressed what it is I am trying to say)???
	Appreciate 0 Quote

08-17-2012, 04:56 AM	#9
wat Enlisted Member 2 Rep 37 Posts Drives: 2015 M4 Join Date: Oct 2010 Location: Switzerland iTrader: (0)	Git rid of your RFTs asap, you'll be glad you did. That's the first thing I did after having bought the car. __________________ 2015 F82 M4 - Mineral Weiss / Black 2014 F10 528i - Jatoba / Black
	Appreciate 0 Quote

08-17-2012, 11:25 AM	#10
Otago Second Lieutenant 23 Rep 244 Posts Drives: 09 Z4 sDrive 30i manual Join Date: May 2009 Location: Hong Kong iTrader: (0)	I have 18 bridgestone rft in fornt and micheline rft in rear, push to 130km no problem in handling.
	Appreciate 0 Quote

09-08-2012, 07:44 AM	#11
dave 48 dave48 0 Rep 5 Posts Drives: 2011 z4 Join Date: Sep 2012 Location: Canada iTrader: (0)	It is true that you should not mix run flat tires and non run flats.I installed a set of bridgestone non run flats and tried the car before installing new front tires .Any speed over 40 miles an hour was scary.
	Appreciate 0 Quote

09-08-2012, 11:06 AM	#12
raven333 Private First Class 7 Rep 175 Posts Drives: Sapphire Black 3.0siM sport Join Date: Jun 2012 Location: United Kingdom iTrader: (0)	Hi! Just to confirm I WILL NOT BE MIXING runflats with non runflats. I have decided that at this time I will replace the rears only with runflats and when the fronts have worn down it will probably match the new rears I will then replace all four with non runflats. I will probably go Goodyear's. The reason for not just going for a set of 4 non-runflats is one of cost. In the UK tyres are very expensive especially when we compare the price you pay in the States and Canada. I worked out that I would be wasting some £400 just for the privilege of running on non-runflats, I will have to be patient !!!
	Appreciate 0 Quote

09-08-2012, 01:19 PM	#13
Vintage Colonel 378 Rep 2,588 Posts Drives: BMW G80 (MT), 718 Spyder Join Date: Aug 2009 Location: Austin, Texas iTrader: (0)	I understand your decision but put 4 Michelin PSS on as soon as possible - it really will transform the car
	Appreciate 0 Quote

09-08-2012, 01:52 PM	#14
raven333 Private First Class 7 Rep 175 Posts Drives: Sapphire Black 3.0siM sport Join Date: Jun 2012 Location: United Kingdom iTrader: (0)	Hi ! thanks for the comments/advice. I did change out the runflats on my 6 series on 19" wheels and it made a major difference in ride and handling.... I will only get about 14k out of the rear bridgestones currently on my car.... I am replacing them with yes bridgestones but I have found a couple at an excellent price otherwise I would never consider them again, so eventually the move to non-runflats will be all the worthwhile....
	Appreciate 0 Quote