Check your tyres!!!
Discussion
Rather a shock today. Took the Nine in for it's MOT, it passed apart from a tyre. But not just any old worn tyre, it is down to the metal strands on the inside egde! Middle and outer edge are just over the limit so was planning to change in spring, but thought it was comfortably legal 
One more drive on that tyre would have likely seen me blowing out in spectacular fashion - fortunate it didn't go pop on the Yorkshire shenanigans.
Moral is, when you check your tyres, run your fingers over the outer, middle and inner edges, and do it properly, like I didn't. My car has a fairly aggressive camber which explains the wear pattern, but even so... was almost brown pants time!!
For info, am replacing with like-for-like Pirellis and doing the whole axle rather than one half worn/one new. Just feels better that way and will have a spare tyre for later if one gets torn/ruined
Enquired about Michelin Pilot Sports, they came up cheaper but were branded Mercedes tyres. Decided to stick with AM Pirellis at the tyre guy's recommendation.
AMDBSNick - the tyres are the black things wrapped round the wheels
One more drive on that tyre would have likely seen me blowing out in spectacular fashion - fortunate it didn't go pop on the Yorkshire shenanigans.
Moral is, when you check your tyres, run your fingers over the outer, middle and inner edges, and do it properly, like I didn't. My car has a fairly aggressive camber which explains the wear pattern, but even so... was almost brown pants time!!
For info, am replacing with like-for-like Pirellis and doing the whole axle rather than one half worn/one new. Just feels better that way and will have a spare tyre for later if one gets torn/ruined
Enquired about Michelin Pilot Sports, they came up cheaper but were branded Mercedes tyres. Decided to stick with AM Pirellis at the tyre guy's recommendation.
AMDBSNick - the tyres are the black things wrapped round the wheels
yeti said:
.
Moral is, when you check your tyres, run your fingers over the outer, middle and inner edges, and do it properly, like I didn't. My car has a fairly aggressive camber which explains the wear pattern, but even so... was almost brown pants time!!
As an alternative to this I suggest you uses your eyes first - the metal threads are very sharp and will easily tear your finger. Believe me, I know from ( painful) experience! Moral is, when you check your tyres, run your fingers over the outer, middle and inner edges, and do it properly, like I didn't. My car has a fairly aggressive camber which explains the wear pattern, but even so... was almost brown pants time!!
Edited by steveatesh on Wednesday 28th November 18:20
Edited by steveatesh on Wednesday 28th November 18:21
brakedwell said:
Also check tyre pressures. Lower temperatures = lower pressures.
In fact, tyres manufacturers recommended pressure is supposed to be adjusted at 20°C. If temperature is lower (as now at any gas station in Luxembourg!), you should increase pressure by 0,1 bar each -10°C: so at 0°C, pressure should be 0,2 bar higher.
yeti said:
AMDBSNick - the tyres are the black things wrapped round the wheels
Evening git face. Fully aware of what tyres are now that Strastone have made me aware that mine are nearly superfluous to requirements. Sadly until the Moose bans young Lewis from the hooter and returns to work I can't afford any new ones 
mikey k said:
If it is wearing on the inside edge you are driving it like an old man 
Seriously get the geo done if one is more worn than the other!
One was replaced halfway through its life due to sidewall damage hence one is wrecked and one is only halfway through its life. Nothing wrong with my geo... You're probably right about the old man driving though, lots of chugging round town Seriously get the geo done if one is more worn than the other!
Stefanolux said:
In fact, tyres manufacturers recommended pressure is supposed to be adjusted at 20°C.
If temperature is lower (as now at any gas station in Luxembourg!), you should increase pressure by 0,1 bar each -10°C: so at 0°C, pressure should be 0,2 bar higher.
Just to clarify this.If temperature is lower (as now at any gas station in Luxembourg!), you should increase pressure by 0,1 bar each -10°C: so at 0°C, pressure should be 0,2 bar higher.
I think you are saying that if you want your tyre to have the correct pressure at 20°C and the temperature when you check the tyre pressure is only 10 degrees you need to put in an extra 0.1 bar.
However if you are filling your tyre and it's 10 degrees when you intend to use it as well then surely the pressure you should fill to is the standard pressure. Ultimately the tyre pressure should be correct for the operating conditions on the day.
If you want to further muddy the waters, depending on how your pressure gauge works you will most probably find that altitude will also affect tyre pressure measurements as will barometric pressure due to weather.
Looks like atmospheric pressure variances could account for as much as 1 psi difference
You'll get an effective increase in measured tyre pressure of 0.5 psi for every 1000 feet of altitude gained.
However this is more often countered by the fact that it's cooler at altitude, which generally works against the increase. So you can pretty much ignore most of that!
What is more relevant is if you are adjusting pressures on a tyre that is heated due to high speed and/or cornering.
On a warm tyre I'd normally allow an extra 3psi (0.21bar) but most importantly I'll make them match side to side.
peterr96 said:
Stefanolux said:
In fact, tyres manufacturers recommended pressure is supposed to be adjusted at 20°C.
If temperature is lower (as now at any gas station in Luxembourg!), you should increase pressure by 0,1 bar each -10°C: so at 0°C, pressure should be 0,2 bar higher.
Just to clarify this.If temperature is lower (as now at any gas station in Luxembourg!), you should increase pressure by 0,1 bar each -10°C: so at 0°C, pressure should be 0,2 bar higher.
I think you are saying that if you want your tyre to have the correct pressure at 20°C and the temperature when you check the tyre pressure is only 10 degrees you need to put in an extra 0.1 bar.
However if you are filling your tyre and it's 10 degrees when you intend to use it as well then surely the pressure you should fill to is the standard pressure. Ultimately the tyre pressure should be correct for the operating conditions on the day.
If you want to further muddy the waters, depending on how your pressure gauge works you will most probably find that altitude will also affect tyre pressure measurements as will barometric pressure due to weather.
Looks like atmospheric pressure variances could account for as much as 1 psi difference
You'll get an effective increase in measured tyre pressure of 0.5 psi for every 1000 feet of altitude gained.
However this is more often countered by the fact that it's cooler at altitude, which generally works against the increase. So you can pretty much ignore most of that!
What is more relevant is if you are adjusting pressures on a tyre that is heated due to high speed and/or cornering.
On a warm tyre I'd normally allow an extra 3psi (0.21bar) but most importantly I'll make them match side to side.
Guycord said:
I usually find a pre-start inspection of kicking all four tyres, tells me everything: tyre pressure, weather, oil level, coolent level, how much gas in the tank and the current market price of the car, not to mention body corrosion or the number of parts made by Lucas. Tried and tested approach used by motorists for years.
Yeah mostly that's what I do too!peterr96 said:
Guycord said:
I usually find a pre-start inspection of kicking all four tyres, tells me everything: tyre pressure, weather, oil level, coolent level, how much gas in the tank and the current market price of the car, not to mention body corrosion or the number of parts made by Lucas. Tried and tested approach used by motorists for years.
Yeah mostly that's what I do too!
I checked the wife's tyres the other day because I walked past the car and noticed they looked pretty flat to me!
The pressure was way down so i pumped them up and as they took shape again i realised she must have been driving around like this for a while.. the outer edges were smooth and the centre of the tyre had pretty much all of its tread left!
The pressure was way down so i pumped them up and as they took shape again i realised she must have been driving around like this for a while.. the outer edges were smooth and the centre of the tyre had pretty much all of its tread left!
AMDBSNick said:
Evening git face. Fully aware of what tyres are now that Strastone have made me aware that mine are nearly superfluous to requirements. Sadly until the Moose bans young Lewis from the hooter and returns to work I can't afford any new ones
Oi Oi Only needed oe but am replacing both so that the car is balanced acorss the axle. Expensive buseiness
I >really< hope theyre still OK for the Geneva trip, shouldn't melt them too much in the weather over the next few months
peterr96 said:
Just to clarify this.
I think you are saying that if you want your tyre to have the correct pressure at 20°C and the temperature when you check the tyre pressure is only 10 degrees you need to put in an extra 0.1 bar.
However if you are filling your tyre and it's 10 degrees when you intend to use it as well then surely the pressure you should fill to is the standard pressure. Ultimately the tyre pressure should be correct for the operating conditions on the day.
What is more relevant is if you are adjusting pressures on a tyre that is heated due to high speed and/or cornering.
On a warm tyre I'd normally allow an extra 3psi (0.21bar) but most importantly I'll make them match side to side.
Tyres will go up less (DeltaT) in cold ambient conditions than hot, so to reach the 'optimum' operating pressure, the theory would be to run slightly higher 'cold' pressures in winter so that you reach the same running pressure.I think you are saying that if you want your tyre to have the correct pressure at 20°C and the temperature when you check the tyre pressure is only 10 degrees you need to put in an extra 0.1 bar.
However if you are filling your tyre and it's 10 degrees when you intend to use it as well then surely the pressure you should fill to is the standard pressure. Ultimately the tyre pressure should be correct for the operating conditions on the day.
What is more relevant is if you are adjusting pressures on a tyre that is heated due to high speed and/or cornering.
On a warm tyre I'd normally allow an extra 3psi (0.21bar) but most importantly I'll make them match side to side.
For example, on a typical saloon (mid-weight) race car on typical track tyres:
Warm day (20C) cold pressure 23C reaches 30C when hot
Cold day (10C) cold pressure 25C reaches 30C when hot
Obviously on a road car a tyre will go up less and will depend on the style of driving and the nature of roads being driven on. To ensure consistent readings, your better off always setting when cold, but I wouldn't say its a big issue as I would be surprised if many drivers can tell the difference a couple of psi makes, for 98% of road driving. Maybe on track you would stand a chance.
Edited by Dingle Dell on Friday 30th November 12:16
My TPMS comes on when it's as cold as it has been this week (around freezing), and shows the pressures to be around 4 psi too low. After a quick high speed blast along the M4 they come up to within 1 psi of the correct pressures.
So I'm not sure if at recommended ambient temp they'd be correct or not!
So I'm not sure if at recommended ambient temp they'd be correct or not!
yeti said:
...Moral is, when you check your tyres, run your fingers over the outer, middle and inner edges, and do it properly,
Good reminder! It happened to me just a few weeks ago. I went to have a slow rear puncture repaired (not the Aston,) took them off and they were bald on the inside! If you have your AM tyres changed, make sure the fitter has lined up the yellow dot on the tyre
with valve on the wheel. Recent picture of a DB9 for sale on PH shows it’s not been fitted to best practice.
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