Michelin PS4

sinistral

sinistral

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keenklee said:
IMHO.
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0) So do these at Day 0, sure, there will be slight difference of tyre pressure between the side facing sun and the side against the sun, but overnight at Day 1 the tyre pressure will be back to equilibrium (start of Day 0). Let's not complicate by saying Day 0 = sunny, day 1 = thunderstorm.

1) On the grand scheme of things, 5kPa out of 220kPa is just about 3%. I think your definition of underinflation and overinflation is already too narrow. My conservative numbers for underinflation and overinflation are +-10 PSI of the recommended cold tyre pressure. The ambient temperature difference in comparison does not change the tyre pressure to either underinflated or overinflated state.

2) The laymen does not have tyre temperature reading available; you cannot just tell them to compensate if they are to pump tyres when it's 'hot'. What works for you does not and will not work for them. The simplest and as recommended method by car manufacturers is to pump the tyres when cold.

The 4 PSI is just an assumption that I had when I drove around without a TPMS, since 4 PSI is also the amount of tyre pressure my tyres loses on a monthly basis. Without knowing the correlation between tyre pressure and tyre temperature for their car, there is no way to get the recommended cold tyre pressure right if the tyres are to be pumped while 'hot'.
 
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keenklee

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sinistral said:
0) So do these at Day 0, sure, there will be slight difference of tyre pressure between the side facing sun and the side against the sun, but overnight at Day 1 the tyre pressure will be back to equilibrium (start of Day 0). Let's not complicate by saying Day 0 = sunny, day 1 = thunderstorm

Things are not complicated if it is known.

1) On the grand scheme of things, 5kPa out of 220kPa is just about 3%. I think your definition of underinflation and overinflation is already too narrow. My conservative numbers for underinflation and overinflation are +-10 PSI of the recommended cold tyre pressure. The ambient temperature difference in comparison does not change the tyre pressure to either underinflated or overinflated state.

Safety aside, if you're ok with the decrease in contact patch size, that's fine. +- 20 kPA ( i guess you do not mean +- 10 PSI ) also makes no difference. By your definition, there is no longer the need to wait for 6 hours or drive less than a few km to the petrol station to pump. My definition is simple, if less, is under inflated and if more, it is over inflated.


2) The laymen does not have tyre temperature reading available; you cannot just tell them to compensate if they are to pump tyres when it's 'hot'. What works for you does not and will not work for them. The simplest and as recommended method by car manufacturers is to pump the tyres when cold

You should refer to what I have first describe in post #39.
For the layman, if don't know, better not to do it.


The 4 PSI is just an assumption that I had when I drove around without a TPMS, since 4 PSI is also the amount of tyre pressure my tyres loses on a monthly basis. Without knowing the correlation between tyre pressure and tyre temperature for their car, there is no way to get the recommended cold tyre pressure right if the tyres are to be pumped while 'hot'.

Like I said, the 4 PSI rule of thumb is on the internet. You are free to make sense on the tyre pressure loss by your definition. I can only say in my experience that the pressure loss is not consistent monthly. I guess you probably or might not be interested - car manufacturer or tyre manufacturer don't seem to have said it. Anyway, no difference.

P.S. When I experience more tyre pressure lost, every two days, on my route, I will drop by the SAME petrol station to pump at the same pump. Early morning, the TPMS will usually show the same readings except for one tyre where it may show under. En-route to the pump, that tyre will show same pressure as the other side. That's the benefit of pumping tyre when they are hot.


IMHO.
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sinistral

sinistral

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@keenklee

No, I really meant +-10 PSI from cold. I have seen a lady driver driving with low 10+ PSI rear tyre on lane 1 of the expressway. It is very obvious with the flat shape of an underinflated tyre. Your stated overinflated tyres resulting in decreased contact size is really nothing compared to that.

I am quite sure most car owner's manual state to inspect cold tyre pressure monthly, and to pump the tyres accordingly. If you are doing this once every two days, I have to give in to your tenacity.

I had a bad experience with a petrol station air pump, with a malfunctioning pressure sensor causing my tyre to go above 50 PSI. That's why I bought a portable air pump and pump my tyres cold at my place's MSCP monthly.
 
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keenklee

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sinistral said:
@keenklee

No, I really meant +-10 PSI from cold. I have seen a lady driver driving with low 10+ PSI rear tyre on lane 1 of the expressway. It is very obvious with the flat shape of an underinflated tyre. Your stated overinflated tyres resulting in decreased contact size is really nothing compared to that.

I am quite sure most car owner's manual state to inspect cold tyre pressure monthly, and to pump the tyres accordingly. If you are doing this once every two days, I have to give in to your tenacity.

I had a bad experience with a petrol station air pump, with a malfunctioning pressure sensor causing my tyre to go above 50 PSI. That's why I bought a portable air pump and pump my tyres cold at my place's MSCP monthly.
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IMHO.
No point discussing further.
 
blackestvoid

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wah from wondering if PS4 tend to lose pressure faster to phd on pumping air at different temperature
 
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keenklee

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blackestvoid said:
wah from wondering if PS4 tend to lose pressure faster to phd on pumping air at different temperature
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IMHO.
For a night driver, when tyres are new, pressure loss will be faster initially and gradually slow down.
If drive in moderate and heavy rain, best is to check tyre pressure more regularly.
On a bright note, you do not need to pump paid nitrogen. :cool:
 
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