Tyre speed limits - what's the tolerance?
Discussion
I just drove from Frankfurt to Nuremburg and annoyingly windscreen said stay at 210km/h. While I did this and interestingly didn't get overtaken once, when I drive back in a few days time I'd much rather do 250km/h (and it's a 340i so perfectly capable of it), cause I feel it's a moral obligation to use a car properly and set a good example to my daughter.
If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
Unless youve cheaped out on tyres on a powerful rwd car, id have thought they would almost certainly be Y rated, which is good for 300kph.
Or are they on winters or something?
Possible theyre W, in which case thats still good to 270kph.
Anything less than W shouldn't be on the car.
Also why is the windscreen telling you what speed to do? Have you got some speed limiter set or something? But yeah, if tyres are W or Y rated, crack on at 250kph.
Or are they on winters or something?
Possible theyre W, in which case thats still good to 270kph.
Anything less than W shouldn't be on the car.
Also why is the windscreen telling you what speed to do? Have you got some speed limiter set or something? But yeah, if tyres are W or Y rated, crack on at 250kph.
Edited by brillomaster on Friday 6th November 03:47
These are either H rated winter tyres or the winter tyre limiter has been set.
ETA: The tolerance is whatever the speedo is out compared to actual road speed. If you have an accident and are found to have exceeded the limit of the tyre you don't want to go there.
Check what tyres are on the car and go from there.
ETA: The tolerance is whatever the speedo is out compared to actual road speed. If you have an accident and are found to have exceeded the limit of the tyre you don't want to go there.
Check what tyres are on the car and go from there.
Edited by ST3.14159265358979323846 on Friday 6th November 05:59
A tyre’s speed rating tells you what it’s been tested and certified to handle under specific laboratory conditions. It doesn’t mean it’s guaranteed to sit at that speed indefinitely in the real world.
I know that doesn’t really answer your question, but it’s something to keep in mind.
I know that doesn’t really answer your question, but it’s something to keep in mind.
I’m assuming it’s a hire car. If you rented it in Germany then I’m pretty sure it’s illegal to fit the wrong tyre speeds over there.
My brother has lived in Germany for 15 years now. He’s always saying how strict the Germans are compared to back in the uk when it comes to cars and safety etc.
I’d be amazed if the hire company fitted the wrong tyres.
My brother has lived in Germany for 15 years now. He’s always saying how strict the Germans are compared to back in the uk when it comes to cars and safety etc.
I’d be amazed if the hire company fitted the wrong tyres.
MB140 said:
I m assuming it s a hire car. If you rented it in Germany then I m pretty sure it s illegal to fit the wrong tyre speeds over there.
My brother has lived in Germany for 15 years now. He s always saying how strict the Germans are compared to back in the uk when it comes to cars and safety etc.
I d be amazed if the hire company fitted the wrong tyres.
I'm fairly sure they're allowed to fit higher speed tyres (than the papers specify).My brother has lived in Germany for 15 years now. He s always saying how strict the Germans are compared to back in the uk when it comes to cars and safety etc.
I d be amazed if the hire company fitted the wrong tyres.
And if the rental company put in a 210 sticker, then they presumably aren't going to fit tyres rated lower than 210, but that doesn't mean they won't be faster.
This time of year the car is likely already on winters or all-seasons, but I honestly don't know what date they'd switch over.
Edited by fourthpedal on Friday 6th November 14:06
If you look in the owners manual I suspect that on the tyre specifications table it will have the winter tyre size and rating listed with an H.
That is why they will put the 210kph sticker on (legal requirement where winter tyre speed rating is lower than maximum vehicle design speed).
I think Mercs have this in the actual driver's cluster (i.e. you select Winter tyres, and it automatically limits speed to 210kph with a reminder).
I doubt they'd fit higher rated tyres to the rental car, but even if they do I'd say you're in a bit of a grey area - you technically don't fall foul of the law (unless they're V rated tyres which are good to 240kph, in which case if you don't have a 240kph sticker, you're falling foul of the rules). But you are running the car at higher speeds on winters than it is certified to.
also probably why nobody was overtaking you at 210kph
That is why they will put the 210kph sticker on (legal requirement where winter tyre speed rating is lower than maximum vehicle design speed).
I think Mercs have this in the actual driver's cluster (i.e. you select Winter tyres, and it automatically limits speed to 210kph with a reminder).
I doubt they'd fit higher rated tyres to the rental car, but even if they do I'd say you're in a bit of a grey area - you technically don't fall foul of the law (unless they're V rated tyres which are good to 240kph, in which case if you don't have a 240kph sticker, you're falling foul of the rules). But you are running the car at higher speeds on winters than it is certified to.
also probably why nobody was overtaking you at 210kph
Somewhatfoolish said:
I just drove from Frankfurt to Nuremburg and annoyingly windscreen said stay at 210km/h. While I did this and interestingly didn't get overtaken once, when I drive back in a few days time I'd much rather do 250km/h (and it's a 340i so perfectly capable of it), cause I feel it's a moral obligation to use a car properly and set a good example to my daughter.
If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
Username checks out, why would you want to put your daughter at risk for a bit of speed? If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
Even brand new tyres can let go.
I would check this carefully before attempting this.
Back home (non-UK) we had a really bad accident on the news a few years ago involving a Cayenne that was on winter tyres.
Owner's son decided to show off to a friend by taking it up to 250kph, had a blowout and left the road.
Sadly, he went into a parked car (in a rest area) with a mum and two children in it while dad was in the toilets...
All 3 passengers in parked car dead on collision, plus the two guys in the Cayenne.
Don't even want to think of what that dad went through.
Back home (non-UK) we had a really bad accident on the news a few years ago involving a Cayenne that was on winter tyres.
Owner's son decided to show off to a friend by taking it up to 250kph, had a blowout and left the road.
Sadly, he went into a parked car (in a rest area) with a mum and two children in it while dad was in the toilets...
All 3 passengers in parked car dead on collision, plus the two guys in the Cayenne.
Don't even want to think of what that dad went through.
There isn't a tolerance,if you drive any speed rated tyre continuously at the max speed,it will fail eventually.If you want to cruise at very high speed for hours even a Z rated tyre is going to fail eventually.
These speed ratings give the impression because they use the word continuous that you can actually cruise indefinitely at their max rating,you can't safely.
Always choose a tyre rated a speed level higher, or reduce your speed to the tyre rating lower.That is your tolerance.
These speed ratings give the impression because they use the word continuous that you can actually cruise indefinitely at their max rating,you can't safely.
Always choose a tyre rated a speed level higher, or reduce your speed to the tyre rating lower.That is your tolerance.
Somewhatfoolish said:
I just drove from Frankfurt to Nuremburg and annoyingly windscreen said stay at 210km/h. While I did this and interestingly didn't get overtaken once, when I drive back in a few days time I'd much rather do 250km/h (and it's a 340i so perfectly capable of it), cause I feel it's a moral obligation to use a car properly and set a good example to my daughter.
If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
If the sticker in the hire car (?) says stay below 210 ( presumably not “stay at 210”!) then I imagine there may be small print in your docs that exceeding this invalidates the insurance.If the speed codes on the tyres, which I didn't check, turn out to acutally be for 250 (and I don't see why they can't be; my winter tyres in the UK generally are) then I'll just do that. If they however are actually set to 210 then what speed can I actually safely do - I assume there's some sort of margin?
I personally would never do 200+ with one of my children, and you said you were never overtaken on your outward journey. Maybe Germans realise that just because you ‘can’ doesn’t mean you ‘should’
astonman said:
There isn't a tolerance,if you drive any speed rated tyre continuously at the max speed,it will fail eventually.If you want to cruise at very high speed for hours even a Z rated tyre is going to fail eventually.
In this case a Y or (Y) rating is higher. Z is a bit old school. Yeah , I meant (Y), I've been involved with speed rating since most performance tyres were H and supercars had V.
Does anyone genuinely believe a (Y) rated tyre is 100% safe from structural failure at a steady 200mph, for hours?
The same criteria apply to the lower speed ratings,its just you can actually cruise at there max rating for hours on a lower rated tyre, that's where the danger lies.
Does anyone genuinely believe a (Y) rated tyre is 100% safe from structural failure at a steady 200mph, for hours?
The same criteria apply to the lower speed ratings,its just you can actually cruise at there max rating for hours on a lower rated tyre, that's where the danger lies.
Edited by astonman on Saturday 7th November 11:47
Setting a good example to your daughter would probably be not driving at 155mph just because you can on an autobahn.
I've just come back from Germany myself so I know how cold it's getting over there now and I wouldn't be doing that speed with anyone else in the car, let alone my children. I was over there in an M4 for reference so more capable than a 340i is and I wouldn't be doing those speeds on the Autobahn in the current conditions. I have done them before, in the car on my own on a bright sunny day with optimal traffic conditions just to try it.
I've just come back from Germany myself so I know how cold it's getting over there now and I wouldn't be doing that speed with anyone else in the car, let alone my children. I was over there in an M4 for reference so more capable than a 340i is and I wouldn't be doing those speeds on the Autobahn in the current conditions. I have done them before, in the car on my own on a bright sunny day with optimal traffic conditions just to try it.
SuperPav said:
If you look in the owners manual I suspect that on the tyre specifications table it will have the winter tyre size and rating listed with an H.
That is why they will put the 210kph sticker on (legal requirement where winter tyre speed rating is lower than maximum vehicle design speed).
I think Mercs have this in the actual driver's cluster (i.e. you select Winter tyres, and it automatically limits speed to 210kph with a reminder).
I doubt they'd fit higher rated tyres to the rental car, but even if they do I'd say you're in a bit of a grey area - you technically don't fall foul of the law (unless they're V rated tyres which are good to 240kph, in which case if you don't have a 240kph sticker, you're falling foul of the rules). But you are running the car at higher speeds on winters than it is certified to.
also probably why nobody was overtaking you at 210kph
Hmm, are you sure about all of that? I have my car's (German-issued) certificate in front of me. It shows:That is why they will put the 210kph sticker on (legal requirement where winter tyre speed rating is lower than maximum vehicle design speed).
I think Mercs have this in the actual driver's cluster (i.e. you select Winter tyres, and it automatically limits speed to 210kph with a reminder).
I doubt they'd fit higher rated tyres to the rental car, but even if they do I'd say you're in a bit of a grey area - you technically don't fall foul of the law (unless they're V rated tyres which are good to 240kph, in which case if you don't have a 240kph sticker, you're falling foul of the rules). But you are running the car at higher speeds on winters than it is certified to.
also probably why nobody was overtaking you at 210kph
- A max speed (only 213km/h, it's a baby car).
- Default tyre types (speed code Y, so 300 km/h).
- Additional tyre types. Some of them include "M+S" (which is an older winter tyre designation, but by itself wouldn't qualify as a winter tyre any more). The speed codes for the M+S types are mostly H (210km/h), one is V (240km/h).
Per my understanding, in Germany there is absolutely no restriction on fitting tyres with a higher speed code than certified. And per my car's certificate, there's no single winter tyre speed - there's just a minimum requirement for each tyre size. So if the tyres are legal for the car, the speed is legal for the tyres, and the speed is legal for the car, is there really an issue that the certificate specified a lower minimum speed for the tyre size? (It's academic for my car as all tyres are at least as fast as the car's max speed.)
astonman said:
Yeah , I meant (Y), I've been involved with speed rating since most performance tyres were H and supercars had V.
Does anyone genuinely believe a (Y) rated tyre is 100% safe from structural failure at a steady 200mph, for hours?
The same criteria apply to the lower speed ratings,its just you can actually cruise at there max rating for hours on a lower rated tyre, that's where the danger lies.
Can you expand on that? As someone who generally knows stuff about cars, but knows nothing about the specifics of speed rating, a layman as it were, in the absence of other guidance - such as in the car manual, I'd expect a car that can do a high speed to be able to do that high speed continuously for a reasonable length of time. Dunno but maybe 2 hours, or most of a tank of fuel.Does anyone genuinely believe a (Y) rated tyre is 100% safe from structural failure at a steady 200mph, for hours?
The same criteria apply to the lower speed ratings,its just you can actually cruise at there max rating for hours on a lower rated tyre, that's where the danger lies.
What is the time it's safe from structural failure and how would I work that out? I assume you are saying that it's way less then a tank of fuel for example?
I think others have called the OP out .
If any of his post is true ,and he is not a dreamer in the back bedroom of his mum's house , then it's pathetic and irresponsible.
Claiming to have a child in the car and driving at excessive speed, without clearly understanding the max speed of a tyre.
That's a tyre in perfect condition,at the correct pressure, in a controlled environment with no debris on the road .
Perhaps the sticker on the windscreen was there for people like you .
If any of his post is true ,and he is not a dreamer in the back bedroom of his mum's house , then it's pathetic and irresponsible.
Claiming to have a child in the car and driving at excessive speed, without clearly understanding the max speed of a tyre.
That's a tyre in perfect condition,at the correct pressure, in a controlled environment with no debris on the road .
Perhaps the sticker on the windscreen was there for people like you .
cliffords said:
I think others have called the OP out .
If any of his post is true ,and he is not a dreamer in the back bedroom of his mum's house , then it's pathetic and irresponsible.
Claiming to have a child in the car and driving at excessive speed, without clearly understanding the max speed of a tyre.
That's a tyre in perfect condition,at the correct pressure, in a controlled environment with no debris on the road .
Perhaps the sticker on the windscreen was there for people like you .
Yes, I think we have worked out that if the OP wants to go significantly faster than the rating of his tyres then he's definitely up for a Darwin award and has no right to remove his daughter from the gene pool other than she might have inherited those genes. The gene pool is enhanced by the removal of both.If any of his post is true ,and he is not a dreamer in the back bedroom of his mum's house , then it's pathetic and irresponsible.
Claiming to have a child in the car and driving at excessive speed, without clearly understanding the max speed of a tyre.
That's a tyre in perfect condition,at the correct pressure, in a controlled environment with no debris on the road .
Perhaps the sticker on the windscreen was there for people like you .
On the Darwin awards, the guy who strapped a JATO to his car was the best!
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