ogawisdom:


In other words pumping tyres are best done in d afternoon or it doesn't Matter

It matters a lot.

Do what the car manufacturer says. In my case as shown in the picture above, my car says cold and that is preferable in the morning.

What i have said before is for those who guage their tires 40psi flat. If they do that in the morning, then its dangerous since the temperature will go higher when the tire gets hot.

As shown below, my car tire has a maximum pressure rating of 44psi. If i inflate in the morning to 40psi and by after noon because of temperature it gets to 45psi, that will be over the max from there it is susceptible to exploding. There are some guages that are wrongly calibrated or the vulcanizer may not be very accurate then pumps 45 or 50psi actually. That will be really dangerous since hot temperature could get the pressure to 50-55psi.

anigbajumo:



If the water will have any effect on the tyre,I think is not a must to reach 100 degree Celsius before it reduces or increases it pressure.I fink the volume need to be considered than the temperature of the water because the volume will determine the pressure of tyre on asphalt than temperature of water inside the tyre.

Pls I dnt get u here, educate me on how dry air can expand in a closed system.If other physical properties remain constant except increase in volume.

. Hot air expands/tends to expand in a system be it close or open. Only in an open system it expands n relieves pressure whereas in a closed system it expand n burst the walls of the system depending on the amount of pressure buildup or the strength of wall.
Bck to the topic moisture in tyre will only become dangerous after 373K,albeit depending the volume of moisture or tyre. Steam expands sporadically beyond 373K, this's always been a threat to boilers

anigbajumo:


The little quantity of water in the tyre (moisture) wnt affect or increase the pressure during the hot time...There is no way u pump a tyre or using compressor to pump any device that u wnt see little drop of water which I think is not enough to reduce or increase the pressure of the tyre on asphalt.

Pls quote me back after yer research.I dnt fink is easy for u to know or determined the little water in type after it has been pumped to like 50 pal.

I am not carrying out any research; just stated my observation. Thanks for your response; good to hear the risk is negligible.

Most responses say there is no risk. Let's hope it is strictly true.

Maybe I should care less now.

adanny01:


Where is temperature? Both Charles and Boyle's law relates to temperature. Why did you keep it aside?

Anyways, sorry that i didnt mention all the laws and the particular one relating to this matter. There are actually 3 gas laws with respect to pressure, volume and temperature. I mentioned the first 2 but forgot the name of the last. I just remembered it.

Its Gay-Lussac's law which states that when a volume of a gas is kept constant pressure is directly proportional temperature.

Note that a tire only changes in shape but not in volume. Any tire that changes in volume will not carry the weight of the car.

Pressure cooker, constant volume, increase in temperature gives rise to increase in pressure.

The Nescafe can example volume is kept constant to a limit, as temperature increases pressure in the can increases till the cover (volume) can no longer hold the pressure.

Tyres do change volume. That's why we "inflate" and not panelbeat them.

DaimlerBen:

Tyres do change volume. That's why we "inflate" and not panelbeat them.

Totally wrong there. A balloon changes volume but a tire cannot change in volume. If a tire changes volume it will go flat under the weight of the car just like a balloon would. Tire changes shape not volume and a balloon changes both shape and volume.

A balloon can be 5cm but inflated to 50cm but a 5cm tire remains a 5cm tire no matter the pressure.