Runflat and non-Runflat Tyre Compatibility.

[E55BOF]

Good evening all. I've just had to put two new tyres on the nearside of the E63 (Goodyear Eagle F1s, chosen because they are very quiet, have good wet grip, and were immediately available). They are the correct sizes, and have the correct speed and load ratings.

On the offside I now have a 285/30/19 Pirelli P Zero with 5 mm tread on the rear, and a 255/35/19 Michelin Pilot Supersport with 4 mm tread on the front. According to the tyre fitter, the Michelin is a runflat.

I'm pretty sure I will have no problems adapting to any slight differences in grip between the sides and ends, but is this mix of tyres likely to cause any problems with the car's ABS or ESP systems, does anybody know?

 

[markjay]

Tricky one... the Self-Supporting Runflat (SSR) tyre will have stiffer sidewall, so in theory mixing standard tyres with SSR tyres could affect the handling of the car. Not sure how noticeable this will be though.

Regarding the ABS/ESP... the recommendation is to use tyres of 'identical make and model and of similar wear'... said that I have never heard of any ABS/ESP issues resulting from having tyres with different wear or different thread pattern, i.e. as long as the tyres are all of the correct size and inflated to the correct pressures you should be fine.

 

[zipdip]

Well as marjay says this is a interesting question,with abs on a car will it be sensitive enough to detect a slight difference between different tyres and their road holding/braking capabilities,I have never read anything that suggests that it can,only it is not a good thing to mix different tyres on the same axle,my gut feeling is I would not use them.or look for part worn to match either tyre.

 

[Will]

I’d put another two (new) matching tyres on the car and stick the other two on eBay.

 

[GeeJayW]

I’d put another two (new) matching tyres on the car and stick the other two on eBay.

^^This...

 

[James Copeland]

I’d put another two (new) matching tyres on the car and stick the other two on eBay.
Absolutely Don't risk a life either yours or someone else for a few ££

 

[E55BOF]

If none of the car's electronic wizardry is likely to be affected, I think I'll suck it and see how it goes.

"Risk a life"? We're not talking about mixing on the same axle a worn-out budget crossply down to the cords and the latest super-sticky radial here. C'mon, gentlemen; sense of proportion, please...

 

[Will]

I wouldn’t say that the risk was all that great, but at 4mm that tyre is going to need changing sooner rather than later anyway. They always drive nicer on new tyres so easier to get it done now (and maybe get a few quid back for the others) - if you’re going to wear it down to 1.6mm or whatever you’d obviously get nothing back (and probably pay the disposal charge)

Man maths

 

[bluestreak]

Different tyre makes and models may have slight variation in rolling radius. Car may or may not be sensitive to that. Only time will tell. On some cars ESP may go into limp mode because of this. Sometimes steering can pull to one side...

It is generally simpler to put matching tyres on the same axle than dealing with side effects of being creative.

Sent from my SM-G955F using Tapatalk

 

[PobodY]

If none of the car's electronic wizardry is likely to be affected, I think I'll suck it and see how it goes.

"Risk a life"? We're not talking about mixing on the same axle a worn-out budget crossply down to the cords and the latest super-sticky radial here. C'mon, gentlemen; sense of proportion, please...

I see plenty of cars driving around with miss-matched tyres on one axle or the other, and they're always on the road and not in the gutter or wrapped around a tree.

If you were talking about a high performance car that needs every ounce of grip, or you were driving on the ragged edge, that might be a different matter.

 

[PobodY]

Actually, I guess the E63 is a high performance AMG model, so maybe there is some validity to the argument.

 

[E55BOF]

If you were talking about a high performance car that needs every ounce of grip, or you were driving on the ragged edge, that might be a different matter.

I don't drive on the ragged edge, though. You can't really do that on the road in something like an E63. Well, I can't/won't, anyway; that really would be putting life at risk ...

I'll see how it goes.

 

[GeeJayW]

I don't drive on the ragged edge, though. You can't really do that on the road in something like an E63. Well, I can't/won't, anyway; that really would be putting life at risk ...

I'll see how it goes.

Run Flat Tyres - The Definitive Guide - National Tyres and Autocare
To Mix Tires, Or Not To Mix Tires? That Is The Question. | Continental

Mixing end to end is bad enough, mixing side to side is a no-no.

Might be a good idea to check with your insurer. Wouldn't be good if they use your choice of tyres as an excuse to void your cover in the event of an incident/accident.

 

[E55BOF]

One question, though; do runflats have a sidewall marking to that effect? If so, mine isn't a runflat at all.

 

[GeeJayW]

One question, though; do runflats have a sidewall marking to that effect? If so, mine isn't a runflat at all.

Ours (Pirelli P Zero) have Runflat on the sidewall. They also have MOE which is also an MB reference to runflat and they have 'outside' on the outer sidewall.

 

[E55BOF]

Run Flat Tyres - The Definitive Guide - National Tyres and Autocare
To Mix Tires, Or Not To Mix Tires? That Is The Question. | Continental

Mixing end to end is bad enough, mixing side to side is a no-no.

Might be a good idea to check with your insurer. Wouldn't be good if they use your choice of tyres as an excuse to void your cover in the event of an incident/accident.

Thank you for that, but you'll forgive me if I don't attach total credence to all advice from companies, or bodies, whose business is selling tyres or representing the interests of those who do, particularly when it urges that one should buy more tyres than might be thought strictly necessary. As Mandy Rice-Davies famously said: "Well, they would say that, wouldn't they?"

I doubt an insurer would void cover if all tyres on a car were MoT-legal, and precisely as specified by the manufacturer as to construction, size, load rating and speed rating. Driving on a flat runflat, with the other three fully-inflated non-runflats, might be a different matter, but that wouldn't happen; I have a spare wheel.

I did glean one piece of genuinely useful information from the links, though; Michelin runflats are marked ZP (for Zero Pressure). My remaining Michelin has no such marking, so it is not a runflat.

So: I have three different makes of premium tyre, all precisely as specified by the manufacturer as to construction, size, load rating and speed rating, on my car; the only difference is a couple of mm tread depth between one side and the other. You may assume I will sleep easily tonight...

 

[rf065]

One question, though; do runflats have a sidewall marking to that effect? If so, mine isn't a runflat at all.

Yes they are all marked, but different markings. See Below........

Run-flat tyres – markings » Oponeo.co.uk

 

[GeeJayW]

Thank you for that, but you'll forgive me if I don't attach total credence to all advice from companies, or bodies, whose business is selling tyres or representing the interests of those who do, particularly when it urges that one should buy more tyres than might be thought strictly necessary. As Mandy Rice-Davies famously said: "Well, they would say that, wouldn't they?"

I doubt an insurer would void cover if all tyres on a car were MoT-legal, and precisely as specified by the manufacturer as to construction, size, load rating and speed rating. Driving on a flat runflat, with the other three fully-inflated non-runflats, might be a different matter, but that wouldn't happen; I have a spare wheel.

I did glean one piece of genuinely useful information from the links, though; Michelin runflats are marked ZP (for Zero Pressure). My remaining Michelin has no such marking, so it is not a runflat.

So: I have three different makes of premium tyre, all precisely as specified by the manufacturer as to construction, size, load rating and speed rating, on my car; the only difference is a couple of mm tread depth between one side and the other. You may assume I will sleep easily tonight...

As long as you're happy, no wuckers! I really don't like mixing tyres, especially on the same axle across the car, but sometimes I guess it's unavoidable and in your case it seems that they are all conventional radials, so not a big deal.

 

[E55BOF]

I really don't like mixing tyres, especially on the same axle across the car

I'm not keen either, and when the ones on the driver's side are ready for a change, the new now ones will be the same couple of mm behind, so I'll change in axle pairs as the need arises.

 

[c63chris]

For what it’s worth I found a marked difference in the handling of my SL on Goodyear’s compared to the Pirelli’s on the rear. It’s not advisable to mix them as others have said but not going to be the end of the world either.