Best way of mixing RF and Non RF

Googlyamnesiac · 12-05-2009, 06:44 AM

Sorry for all the tyre threads lately! Wasn't sure if I should open a new thread but since its a different question then thought it was ok!

Is it better to have RF on the front and Non RF on the back or the other way around or would it not make a difference?

I know some people are saying dont mix even if on different axles but I think i'm going to have to. This way the tyres will both be run down at the same point so I can upgrade to 19" in the summer.

Also how low do you guys recommend to let the tread go on the rear? I think there must be about 2mm - 2.5mm left on my rears, should I wait a few weeks or just get some new ones now? (only used the 10p trick so sorry for the estimate!).

dxb335d · 12-05-2009, 06:50 AM

Craziest and stupidest idea ever. Not a good idea. The tyres are not only different compounds but are of completely different in construction. Car would be very unsettled. Dangerous infact.

Regarding depth, legal min is 1.6, which in reality is too far low for the winter. 2MM should be the legal limit I rekon. best to change before that also.

Check the inside edges. Mine can have 5mm on outside and only 2mm on the inside of the rears.

Googlyamnesiac · 12-05-2009, 07:01 AM

argh! I thought people said it was generally ok to have non run flats on one axle and run flats on the other? Sure the handling might be slightly different but not to the point where I would be flying off the road at every opportunity?

Stupidest idea ever? eeek.

dxb335d · 12-05-2009, 07:15 AM

Quote:

Originally Posted by idlerobbo

argh! I thought people said it was generally ok to have non run flats on one axle and run flats on the other? Sure the handling might be slightly different but not to the point where I would be flying off the road at every opportunity?

Stupidest idea ever? eeek.

Mate, i didnt mean to cause offense with the stupid comment. i retract that. Although it is far from advisable to run Non runflat and runflat on a car. Either stick with Runflats, or non. Plenty of rubber for sale on ebay mate if you dont want to spend mountains.

Googlyamnesiac · 12-05-2009, 07:20 AM

oh you didn't offend me mate. I've just spent the last week deciding what to do for the best.

- 4 new 19" alloys with Toyo tyres fitted £799
- 2 new 16" Falken non runflats on the rear until the summer £136
- 4 new 16" Falken non runflats £258

Now I had just decided on the 2 new Falkens when I wondered the question of this forum.

me = confuzzled!

Petem95 · 12-05-2009, 07:52 AM

I've been trying to decide what to do regarding the runflat/non-runflat situation as well, seeing as one of my rears is getting low (approx 2mm)

I've decided to just change that one for a runflat as all the other tyres are pretty good, but it's a tough one!

hmi1750 · 12-05-2009, 08:57 AM

I have Falkens at the back and PS2 runflats front.. yes the car is not as perfect as it was before on Goodyr Assym all around (non-rft) but it is perfectly safe.

foxy-367 · 12-05-2009, 10:40 AM

I can't believe it would be Dangerous it'd be like having michelins on the front and bridgestones on the back, not recommended but not dangerous. The subtle handling balance would definately be changed but lets face it unless you are doing the Ring or track days it would not make a difference on the road. The tyre would not explode and so long as the pressures were correct it would not be an issue IMO.

Googlyamnesiac · 12-05-2009, 01:22 PM

damnit! I just shelled out £800 on 4 19" rims with tyres :-)

pictures to come!

p.s. i'm happy! No run flats = superb!

gIzzE · 12-05-2009, 03:29 PM

Good move.

It is dangerous to mix run flats with non run flats, the problem is you will only realise just how dangerous it is when you really need them.

foxy-367 · 12-06-2009, 11:59 AM

Quote:

Originally Posted by gIzzE

Good move.

It is dangerous to mix run flats with non run flats, the problem is you will only realise just how dangerous it is when you really need them.

Why?

Could only be as dangerous as having non-RFT tyres surely?

Googlyamnesiac · 12-06-2009, 12:07 PM

Seems we all need to agree to disagree on this one!

I can't really comment though since I now have 4 non RFs. The handling feels loads better though.

gIzzE · 12-06-2009, 01:27 PM

Quote:

Originally Posted by foxy-367

Why?

Could only be as dangerous as having non-RFT tyres surely?

Of course not!!

The tyres are two completely different compounds, they both react completely differently when pushed, and this is where the problems arrive.

Try putting a Michelin Pilot Sport on the front axle of a BMW and a Pilot Sport 2 on the rear, both non run flat, and you will see just how twitchy a car can become with just a mix of tyres front and rear.

I have seen hundreds and hundreds of posts on the BMW forums which start...

"My car has started to become very unpredictable, the back end feels loose......" etc. etc.

And every time it is because people have put new tyres on and mixed them, some cars don't mind this, BMWs really really do.

dxb335d · 12-06-2009, 01:29 PM

Always buy a matched set of rubber.

Wingco · 12-08-2009, 03:35 AM

.....probably with a heavy-duty (& large) blender.

doughboy · 12-08-2009, 03:42 AM

Quote:

Originally Posted by dxb335d

Always buy a matched set of rubber.

Exactly, always buy 4 new at a time if you want to change type/make etc. You won't get the benefit of, or be able to judge the performance of the new tyre type otherwise.

Sell your part worns on ebay.......easy.

HighlandPete · 12-08-2009, 03:22 PM

Quote:

Originally Posted by idlerobbo

Is it better to have RF on the front and Non RF on the back or the other way around or would it not make a difference?

I know some people are saying dont mix even if on different axles but I think i'm going to have to. This way the tyres will both be run down at the same point so I can upgrade to 19" in the summer.

Also how low do you guys recommend to let the tread go on the rear? I think there must be about 2mm - 2.5mm left on my rears, should I wait a few weeks or just get some new ones now? (only used the 10p trick so sorry for the estimate!).

Mixing tyres is really a no no. All the tyre manufacturers and the Tyre Council, TyreSafe, trade organizations do not recommend mixing on different axles. Certainly not on the same axle.

As already stated on this thread, tyre characteristics are so different, slip angles are virtually non existent, compared to most non run-flat tyres. We don't want to be seeing the road from behind a hedge!

I personally think the law is not up todate on this part of tyre use. Issues similar to running radials mixed with cross-ply. We'd never think of doing that these days.

BTW, 3mm is the tread depth where changes are wise, if we want reasonable performance from a tyre. Anything less and braking and grip are compromised.

HighlandPete

12-05-2009, 06:44 AM	#1
Googlyamnesiac Captain 60 Rep 743 Posts Drives: 2013 F10 520D Join Date: May 2009 Location: Yorkshire, UK iTrader: (3)	Best way of mixing RF and Non RF Sorry for all the tyre threads lately! Wasn't sure if I should open a new thread but since its a different question then thought it was ok! Is it better to have RF on the front and Non RF on the back or the other way around or would it not make a difference? I know some people are saying dont mix even if on different axles but I think i'm going to have to. This way the tyres will both be run down at the same point so I can upgrade to 19" in the summer. Also how low do you guys recommend to let the tread go on the rear? I think there must be about 2mm - 2.5mm left on my rears, should I wait a few weeks or just get some new ones now? (only used the 10p trick so sorry for the estimate!).
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12-05-2009, 06:50 AM	#2
dxb335d The Tarmac Terrorist 1022 Rep 29,344 Posts Drives: 997.2 GT3 Join Date: Mar 2007 Location: ''Fandango Towers'' iTrader: (3) Garage List 2010 Porsche 997.2 GT3 [9.50] 2003 BMW E46 M3 [6.00] 2007 BMW E92 335D [5.50]	Craziest and stupidest idea ever. Not a good idea. The tyres are not only different compounds but are of completely different in construction. Car would be very unsettled. Dangerous infact. Regarding depth, legal min is 1.6, which in reality is too far low for the winter. 2MM should be the legal limit I rekon. best to change before that also. Check the inside edges. Mine can have 5mm on outside and only 2mm on the inside of the rears. __________________ 997.2 GT3
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12-05-2009, 07:01 AM	#3
Googlyamnesiac Captain 60 Rep 743 Posts Drives: 2013 F10 520D Join Date: May 2009 Location: Yorkshire, UK iTrader: (3)	argh! I thought people said it was generally ok to have non run flats on one axle and run flats on the other? Sure the handling might be slightly different but not to the point where I would be flying off the road at every opportunity? Stupidest idea ever? eeek.
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12-05-2009, 07:20 AM	#5
Googlyamnesiac Captain 60 Rep 743 Posts Drives: 2013 F10 520D Join Date: May 2009 Location: Yorkshire, UK iTrader: (3)	oh you didn't offend me mate. I've just spent the last week deciding what to do for the best. - 4 new 19" alloys with Toyo tyres fitted £799 - 2 new 16" Falken non runflats on the rear until the summer £136 - 4 new 16" Falken non runflats £258 Now I had just decided on the 2 new Falkens when I wondered the question of this forum. me = confuzzled!
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12-05-2009, 07:52 AM	#6
Petem95 Private First Class 21 Rep 110 Posts Drives: 2008 330d M-Sport Join Date: Nov 2009 Location: Leeds, UK iTrader: (0)	I've been trying to decide what to do regarding the runflat/non-runflat situation as well, seeing as one of my rears is getting low (approx 2mm) I've decided to just change that one for a runflat as all the other tyres are pretty good, but it's a tough one! __________________ 2008 E92 330d M-Sport, Sapphire Black, 19" 225M's
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12-05-2009, 08:57 AM	#7
hmi1750 Major 25 Rep 1,130 Posts Drives: M135i Join Date: Jun 2007 Location: London, UK iTrader: (0)	I have Falkens at the back and PS2 runflats front.. yes the car is not as perfect as it was before on Goodyr Assym all around (non-rft) but it is perfectly safe.
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12-05-2009, 10:40 AM	#8
foxy-367 Lieutenant 6 Rep 448 Posts Drives: 320d M-Sport Join Date: Feb 2009 Location: North West iTrader: (0)	I can't believe it would be Dangerous it'd be like having michelins on the front and bridgestones on the back, not recommended but not dangerous. The subtle handling balance would definately be changed but lets face it unless you are doing the Ring or track days it would not make a difference on the road. The tyre would not explode and so long as the pressures were correct it would not be an issue IMO. __________________ Now - E90 320d M Sport, Le Mans Blue, sun protection glass, Auto lights and wipers, 193M, a big grin Previous - Seat Leon FR, Golf Gttdi (x2), Mk3 Fiesta SI, E30 318i Peugeot 205 Roland Garros, Mk2 Fiesta Ghia (it had a rev counter!!!!)
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12-05-2009, 01:22 PM	#9
Googlyamnesiac Captain 60 Rep 743 Posts Drives: 2013 F10 520D Join Date: May 2009 Location: Yorkshire, UK iTrader: (3)	damnit! I just shelled out £800 on 4 19" rims with tyres :-) pictures to come! p.s. i'm happy! No run flats = superb!
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12-05-2009, 03:29 PM	#10
gIzzE Major General 361 Rep 5,985 Posts Drives: F11 + 997 Carrera S Join Date: Apr 2006 Location: Norfolk, UK. iTrader: (2)	Good move. It is dangerous to mix run flats with non run flats, the problem is you will only realise just how dangerous it is when you really need them.
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12-06-2009, 12:07 PM	#12
Googlyamnesiac Captain 60 Rep 743 Posts Drives: 2013 F10 520D Join Date: May 2009 Location: Yorkshire, UK iTrader: (3)	Seems we all need to agree to disagree on this one! I can't really comment though since I now have 4 non RFs. The handling feels loads better though.
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12-06-2009, 01:29 PM	#14
dxb335d The Tarmac Terrorist 1022 Rep 29,344 Posts Drives: 997.2 GT3 Join Date: Mar 2007 Location: ''Fandango Towers'' iTrader: (3) Garage List 2010 Porsche 997.2 GT3 [9.50] 2003 BMW E46 M3 [6.00] 2007 BMW E92 335D [5.50]	Always buy a matched set of rubber. __________________ 997.2 GT3
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12-08-2009, 03:35 AM	#15
Wingco Private 2 Rep 91 Posts Drives: VW CC GT (2013MY) Join Date: Jun 2008 Location: UK iTrader: (0)	.....probably with a heavy-duty (& large) blender. __________________ GONE: 320d Editions SE - SG; Lemon Dakota; V-spokes style188, Hifi Loudspeaker, 6FL, Auto Lights/wipers. HELLO: VW CC GT Deep Pearl Black; Desert-Beige/black leather.
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