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Mixing Run-flats with regular tyres

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portculisz4
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Mixing Run-flats with regular tyres

Post by portculisz4 » Sat Jun 12, 2021 3:24 pm

Owned my E85 2.5i now for about 2 months. Previous owner replaced rear run flat tyres with regular radials of the same size to pass MOT. Question is - is it OK to run with mixed tyre types ? I have run flats on the front and regular on the rear and I am concerned as to whether this would cause a handling issue, I assume it's not illegal as it met the MOT requirements. Would tyre pressure be the same for both types, if not, what would be the recommended pressures for front and rear.

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Mixing Run-flats with regular tyres

Post by mr wilks » Sat Jun 12, 2021 3:51 pm

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Mixing Run-flats with regular tyres

Post by skelters » Sat Jun 12, 2021 4:00 pm

I'll see you're can of worms and raise you some....

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Mixing Run-flats with regular tyres

Post by Zedebee » Sat Jun 12, 2021 4:02 pm

Not answering your question directly, but if you still have the OEM-spec Bridgestone Potenzas on the front, get rid of them; then you’ll be able to drive in a straight line.

I don’t think I’ll be alone on here by saying you should always go for a decent set of matching tyres all round.
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Mixing Run-flats with regular tyres

Post by 1536Z4 » Sat Jun 12, 2021 6:53 pm

From what I have read in the past on other forums the consensus is No .
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Mixing Run-flats with regular tyres

Post by enuff_zed » Sat Jun 12, 2021 8:26 pm

If it were me, the fact that I could tell the insurance company that I legally went backwards through the hedge would not quite cut it.
Ditch the runflats before they ditch you. :thumbsup:
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Mixing Run-flats with regular tyres

Post by Ole gits rule » Sat Jun 12, 2021 8:42 pm

Not illegal but not something I would ever do
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Mixing Run-flats with regular tyres

Post by warmasice » Sat Jun 12, 2021 9:02 pm

I'd never ever run that set up. Sell the fronts, add a little more and get some new non-rft fronts.
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Mixing Run-flats with regular tyres

Post by Mr Tidy » Sat Jun 12, 2021 9:56 pm

While it may be legal I wouldn't want to go far with that mixture fitted.

As others have said I'd get a pair of decent non-runflats on the front.
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Mixing Run-flats with regular tyres

Post by PeteyZ4 » Sat Jun 12, 2021 10:16 pm

Obviously not ideal, but I wouldn't say it's as suicidal as the previous replies seem to make it sound.

I bought my car a couple of months ago and it came with cheapo Jinyu (non RF) on the front and Continental Sport Contact 2 SSR (RF) on the rear. All are about 7 years old as well.

I've even had it up the Buttertubs Pass and The Struggle just a couple of weeks ago and I'm still here!

Plan is only to change when my wallet recovers enough to change the wheels at the same time. 17's on at the moment and I'll be going up to 18's

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Mixing Run-flats with regular tyres

Post by sars » Sat Jun 12, 2021 10:17 pm

As others have said this is a question that’s been asked many times before, ideally you should have the same brand and type/style on each wheel, obviously what you really shouldn’t have is different brands/type/style or significantly different tread depths of an identical tyre on the same axle and what you have is somewhere in between. It’s not really any different than having Goodyear F1 A5’s on the front and Uniroyal Rain Sports on the rear.
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Mixing Run-flats with regular tyres

Post by Jembo » Sat Jun 12, 2021 10:52 pm

IMO It’s the small %age when you have an extreme situation - when the motorway comes to a full dead emergency stop… some nob pulls out on you… it’s raining, you’re going somewhere new & take an unfamiliar bend that’s much sharper than expected.

U have proportionally 4 tiny patches of rubber holding +1 ton of car… having used many brands am surprised just how different they are, borne out by all the nay sayers above.

Yes they’ll go round & round, will different types save your bacon in an emergency or will you qualify for a Darwin Award, your call :thumbsup:
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Mixing Run-flats with regular tyres

Post by Zulu4 » Sun Jun 13, 2021 8:28 am

PeteyZ4 wrote: Sat Jun 12, 2021 10:16 pm Obviously not ideal, but I wouldn't say it's as suicidal as the previous replies seem to make it sound.

I bought my car a couple of months ago and it came with cheapo Jinyu (non RF) on the front and Continental Sport Contact 2 SSR (RF) on the rear. All are about 7 years old as well.

I've even had it up the Buttertubs Pass and The Struggle just a couple of weeks ago and I'm still here!

Plan is only to change when my wallet recovers enough to change the wheels at the same time. 17's on at the moment and I'll be going up to 18's
My feelings too.
If both sets of tyres are from a quality manufacturer with similar grip ratings , you are unlikely to notice any difference, apart from a hard ride at the front.

I found the biggest effect is having a harder compound rubber on the back and a softer (grippier) compound on the front - This makes life very interesting going round a wet roundabout.
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Mixing Run-flats with regular tyres

Post by Scooba_Steve » Sun Jun 13, 2021 9:30 am

4x A5 sized patches of rubber are all that are between you and potential death... better to be a couple of hundred quid poorer.
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Mixing Run-flats with regular tyres

Post by portculisz4 » Sun Jun 13, 2021 11:44 am

Gentlemen, enough said,
I think you have all made the point very clear. RFTs out next week to be replaced by the same make model as the back

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