Winter tyres? Run-flats? I have ALL the answers......
Discussion
I thought I would share my experiences of the above, as you never know it might help someone.
I have just driven 1400 miles through Europe, to the Alps and back.
Requirement
As I thought it was a good idea to be able to get up into the ski resort (and it's a legal requirement?), I sourced some winter tyres. My first experience of such devices (I've used chains up until now), I gave the choice of make/model serious thought.
My car does not have TPMS, but I chose Run-flat winters. Why?
Reasoning
a) If I have a puncture in sub-zero/poor weather conditions, it makes sense not to have to change a wheel in/out of a fully packed car.
b) most of my journey was in the dark, on the autoroute, as it happens in torrential rain, so the chances of being killed at the side of the road were higher than I would choose.
c) if I have a puncture with ordinary winter-tyres, I have to fit the space-saver, which is obviously NOT a winter-tyre. Handling on a loaded car with 3x winter and 1x space-saver might be considered to be 'undesirable' at best.
So with RFT I can decide when/where to exit the main road, and find a local garage/hotel etc etc
However, so many of you lot whinge about run-flats 'ruining the ride' was my only doubt about my decision.
Apples with oranges
To give you the full picture for comparison:
Car is the Legacy Spec.B - this has compliant yet hard/low suspension/chassis from the factory.
My 'summer' wheel/tyre combo is 225/40/18 with (latest-version) P-zeros 92Y, and as I have (several) spare sets of rims I chose 225/45/17 Goodyear Eagles RFT 91H for the winters. Rims are both OE, though the 17s are the Prodrive/OZ P1 wheel which are somewhat lighter.
This increase in sidewall depth will have contributed towards mitigating the stiffer sidewalls. The slightly lighter 17" combo may also have helped.....
Conditions on the journey
Torrential rain mostly, below 7 degrees mostly, good road surfaces even up into the mountains.
In the mountains, around zero degrees, fresh snow on top of packed snow/ice, depending on when the plough had been round.
Conclusions
I was very pleased with the ride - not harsh, but firm (which is the way I like it). In the dry above 7 degrees, you could tell the compound is 'wrong', but the tyres only understeered slightly more when 'pressing-on'.
In the torrential rain the car was rock steady - even when the lorry drivers lane-wandered in front of me and I had to 'adjust'.
But the real difference was in the mountains - on a fresh/packed snow mix the tyres made a huge difference in steering and braking - sure the car would still drift if provoked, but there was always some grip to be had.... and braking was astonishingly good.
My experience of summer tyres in snow is that you can 'go', but steering is compromised and braking is non-existant.
Management summary
Obviously
a) My experience is that winter tyres work well in rain, mud, and obviously snow and ice, and if you have to go anywhere in cold and rain, they make a difference.
How much that difference costs is the issue, and how often do you need it?
Not so obviously
b) Run-flat winters work well on 'ordinary' cars, and the Spec.B's suspension coped well with the extra stiffness (though I admit it is a very highly regarded and not exactly normal setup)
I checked the tyre pressures regularly, but I do that anyway especially on a long journey with a loaded car.
I'd say that run-flat winters are a 'good' idea.
I have just driven 1400 miles through Europe, to the Alps and back.
Requirement
As I thought it was a good idea to be able to get up into the ski resort (and it's a legal requirement?), I sourced some winter tyres. My first experience of such devices (I've used chains up until now), I gave the choice of make/model serious thought.
My car does not have TPMS, but I chose Run-flat winters. Why?
Reasoning
a) If I have a puncture in sub-zero/poor weather conditions, it makes sense not to have to change a wheel in/out of a fully packed car.
b) most of my journey was in the dark, on the autoroute, as it happens in torrential rain, so the chances of being killed at the side of the road were higher than I would choose.
c) if I have a puncture with ordinary winter-tyres, I have to fit the space-saver, which is obviously NOT a winter-tyre. Handling on a loaded car with 3x winter and 1x space-saver might be considered to be 'undesirable' at best.
So with RFT I can decide when/where to exit the main road, and find a local garage/hotel etc etc
However, so many of you lot whinge about run-flats 'ruining the ride' was my only doubt about my decision.
Apples with oranges
To give you the full picture for comparison:
Car is the Legacy Spec.B - this has compliant yet hard/low suspension/chassis from the factory.
My 'summer' wheel/tyre combo is 225/40/18 with (latest-version) P-zeros 92Y, and as I have (several) spare sets of rims I chose 225/45/17 Goodyear Eagles RFT 91H for the winters. Rims are both OE, though the 17s are the Prodrive/OZ P1 wheel which are somewhat lighter.
This increase in sidewall depth will have contributed towards mitigating the stiffer sidewalls. The slightly lighter 17" combo may also have helped.....
Conditions on the journey
Torrential rain mostly, below 7 degrees mostly, good road surfaces even up into the mountains.
In the mountains, around zero degrees, fresh snow on top of packed snow/ice, depending on when the plough had been round.
Conclusions
I was very pleased with the ride - not harsh, but firm (which is the way I like it). In the dry above 7 degrees, you could tell the compound is 'wrong', but the tyres only understeered slightly more when 'pressing-on'.
In the torrential rain the car was rock steady - even when the lorry drivers lane-wandered in front of me and I had to 'adjust'.
But the real difference was in the mountains - on a fresh/packed snow mix the tyres made a huge difference in steering and braking - sure the car would still drift if provoked, but there was always some grip to be had.... and braking was astonishingly good.
My experience of summer tyres in snow is that you can 'go', but steering is compromised and braking is non-existant.
Management summary
Obviously
a) My experience is that winter tyres work well in rain, mud, and obviously snow and ice, and if you have to go anywhere in cold and rain, they make a difference.
How much that difference costs is the issue, and how often do you need it?
Not so obviously
b) Run-flat winters work well on 'ordinary' cars, and the Spec.B's suspension coped well with the extra stiffness (though I admit it is a very highly regarded and not exactly normal setup)
I checked the tyre pressures regularly, but I do that anyway especially on a long journey with a loaded car.
I'd say that run-flat winters are a 'good' idea.
Edited by Orangecurry on Wednesday 29th January 10:49
Monty Python said:
How often do you check the tyre pressures, or do you never go over 50mph?
Whilst doing my research, I found several hundred references telling me that if I couldn't tell I was driving on deflated runflats, I shouldn't be allowed to drive.I assume that is what you are getting at?
Orangecurry said:
Whilst doing my research, I found several hundred references telling me that if I couldn't tell I was driving on deflated runflats, I shouldn't be allowed to drive.
I assume that is what you are getting at?
Not at all - I've had them for over 7 years and on more than one occasion the TPMS has gone off because of a partial deflation and the handling hasn't been noticeably affected. Just curious that's all - most people never check their tyre pressures at all.I assume that is what you are getting at?
I have had two punctures with runflats, both have been catastrophic failures - i.e. the sidewalls have blown out, no chance of driving on flat. Currently also have two awaiting inspection as the sidewalls have huge bulges. These are OEM spec tyres for the vehicle and used in accordance etc.....
I don't think you have ALL the answers unfortunately.
I don't think you have ALL the answers unfortunately.
juliann said:
I have had two punctures with runflats, both have been catastrophic failures - i.e. the sidewalls have blown out, no chance of driving on flat. Currently also have two awaiting inspection as the sidewalls have huge bulges. These are OEM spec tyres for the vehicle and used in accordance etc.....
Weird - perhaps runflats should be renamed.Just so I can worry (or not), are yours Goodyears?
juliann said:
I don't think you have ALL the answers unfortunately.
No - perhaps not.Bonefish Blues said:
Procured a cheap set of Runflat Winters for ours a while back.
Couldn't find anyone locally who would fit them without a TPMS so sold them on after a month or so.
Aren't aftermarket TPMS only 50 quid or so?Couldn't find anyone locally who would fit them without a TPMS so sold them on after a month or so.
And before we get sidetracked, my post was more about how the car/suspension handled on runflats, rather than whether you or I should fit a TPMS.
I would suggest that these tyres have been run deflated for a considerable time.They will only take so much running flat before they overheat and disintegrate.We see this all the time at work,driver declares tyre just exploded without warning,on internal inspection masses of rubber crumb and dust and horrid burnt rubber smell.Even when shown this half of them still insist tyre just let go without warning.
Orangecurry said:
Just so I can worry (or not), are yours Goodyears?
.
Yes, all Goodyear. The two blow outs on the rear of previous 5 series touring (18"); the two bulges on the rear of current model 5 series touring (19")- both these bulged tyres fitted at the same time. There have been plenty of Goodyear runflats in between that haven't failed though..
Currently on 17" non-RFT winters with great comfort but very understeery
V8s ONLY said:
I would suggest that these tyres have been run deflated for a considerable time.They will only take so much running flat before they overheat and disintegrate.We see this all the time at work,driver declares tyre just exploded without warning,on internal inspection masses of rubber crumb and dust and horrid burnt rubber smell.Even when shown this half of them still insist tyre just let go without warning.
I beg to differ. The deflation warning system on the BMW E61 & F11 is pretty sensitive. I check pressures regularly as driving c. 1,000 motorway miles a week, I like to be safe.The fact they're winters would have negated the RFT aspect a little too, as there will be more compliance in the compound / cap.
Good write up though, glad they worked well for you
Oh, and FWIW, you're totally right about driving on a runflat deflated, if you can't tell you shouldn't be driving. Scary how many car journos can't tell though...
Good write up though, glad they worked well for you
Oh, and FWIW, you're totally right about driving on a runflat deflated, if you can't tell you shouldn't be driving. Scary how many car journos can't tell though...
juliann said:
I have had two punctures with runflats, both have been catastrophic failures - i.e. the sidewalls have blown out, no chance of driving on flat. Currently also have two awaiting inspection as the sidewalls have huge bulges. These are OEM spec tyres for the vehicle and used in accordance etc.....
I don't think you have ALL the answers unfortunately.
A sidewall blowing on a runflat is new to me. Got any photos, would be really interested!I don't think you have ALL the answers unfortunately.
Orangecurry said:
Whilst doing my research, I found several hundred references telling me that if I couldn't tell I was driving on deflated runflats, I shouldn't be allowed to drive.
I assume that is what you are getting at?
I had three punctures with my old 3 series with run flats. I had to drive about 10 miles each time to get them replaced. It is like driving with a flat tyre, like you say, if you can't tell, you shouldn't be driving! But I wouldn't like to drive any more than 10 miles!I assume that is what you are getting at?
Incidentally, they seemed better at 50mph then at speeds less than 30 for some reason.
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