That sounds like a Californian concept - the average UK temperature is 10 degrees Celcius - and 30 C is a heatwave!There are 2 camps in temperature/ tyrepressure relation.
The larger camp states that if for instance 40 psi is needed for the load and speed used, you have to fill or measure that at ambiënt temperature, be it 0 degr C / 32 degrF or 40 degrC/ 104 degrF.
I am in the smaller camp together with Porche, BMW, Rimex, that state the determined needed pressure is cold ( when temp in tyre and outside ambiënt temperature are the same) at 20 degrC/ 68 degrF.
So never blead down warm or cold pressure on a 40 degrC hot day.
The tyre needs the lesser heatproduction by lesser deflection, by the higher pressure measured, because cooling down is also lesser, because of lesser temperature differences between tyre-material and in and outside tyre air.
When cold the other way around,but then highening up is allowed for fuellsaving and riding-quality.
I have always checked mine when the tyre is at ambient and the sun isn’t on it. Haven’t even considered the other option.There are 2 camps in temperature/ tyrepressure relation.
The larger camp states that if for instance 40 psi is needed for the load and speed used, you have to fill or measure that at ambiënt temperature, be it 0 degr C / 32 degrF or 40 degrC/ 104 degrF.
I am in the smaller camp together with Porche, BMW, Rimex, that state the determined needed pressure is cold ( when temp in tyre and outside ambiënt temperature are the same) at 20 degrC/ 68 degrF.
So never blead down warm or cold pressure on a 40 degrC hot day.
The tyre needs the lesser heatproduction by lesser deflection, by the higher pressure measured, because cooling down is also lesser, because of lesser temperature differences between tyre-material and in and outside tyre air.
When cold the other way around,but then highening up is allowed for fuellsaving and riding-quality.
Same here in the Netherlands, so cold measured in the shade will give minimal difference between 20 degrC measured.That sounds like a Californian concept - the average UK temperature is 10 degrees Celcius - and 30 C is a heatwave!
UK temperature is officially Celcius but Fahrenheit still used by some - pressure can be psi or bar - speed is officially mph - weight is offically kg/tonnes but lbs/tons still used by some - beer is in pints!Same here in the Netherlands, so cold measured in the shade will give minimal difference between 20 degrC measured.
But if ever only can be measured in extreme ambiënt temperatures, calculate it roughly back to 20 degrC , and go from that. Yesterday it was 37 degrC here( in the shade.
Then to use UK values, do you use Celcius or Fahrenheit, bar or psi, kmph or mph, kg or lbs?
In the Netherlands Celcius, bar, kmph, kg used.
So yust let pressure flow with temperature, easyer and saver system. Only checking mostly, and no adyustment needed.
On my degree in 1971 half the questions were Imperial and the other half SI. We can deal with multiple units but I think that Slugs and Poundals are rarely used if at all. My cars spoil me as units change as I disembark the ferry or tunnel 😂Same here in the Netherlands, so cold measured in the shade will give minimal difference between 20 degrC measured.
But if ever only can be measured in extreme ambiënt temperatures, calculate it roughly back to 20 degrC , and go from that. Yesterday it was 37 degrC here( in the shade.
Then to use UK values, do you use Celcius or Fahrenheit, bar or psi, kmph or mph, kg or lbs?
In the Netherlands Celcius, bar, kmph, kg used.
So yust let pressure flow with temperature, easyer and saver system. Only checking mostly, and no adyustment needed.
There's obviously different opinions - I have a 2016 VW Touareg, the same underneath as a Porsche Cayenne, but no reference to temperature in the handbook section for TPMS.Here a picture of motor tpms . At the end about that they give pressure compensated to 20 degrC.
Porche and BMW do it the other way around.
They give recomended pressure for the setting, calculated from 20 degrC to the temperature in tyre, also sended by the sensors.
But also here the psi list.
In front in degrF and behind in Celcius.
Example: supose you determined 40 psi needed.
Then this is at 21 degrC in tyre, and search that in the list . Gives 5.5 degrC per 1 psi change.
Then if temp in tyre 32 degrC, you read 32-21=11 degr/ 5.5= 2 psi higher is 42 psi you will measure, and leave it there.
Used 21 degr here because 70 degrF first used. But that 1 degr difference wont matter.
Even if calculated from 10 or 30 degrC it wont give dramatic differences
DegrC/psi/psi21C70F/degrF/psi
18,5C/psi/ 1 psi/ 33,5F/psi
17,5C/psi/ 2 psi/ 31,5F/psi
16,5C/psi/ 3 psi/ 30 F/psi
15,5C/psi/ 4 psi/ 28,5F/psi
15 C/psi/ 5 psi/ 27 F/psi
14 C/psi/ 6 psi/ 25,5F/psi
13,5C/psi/ 7 psi/ 24,5F/psi
13 C/psi/ 8 psi/ 23,5F/psi
12,5C/psi/ 9 psi/ 22,5F/psi
12 C/psi/ 10 psi/ 21,5F/psi
11,5C/psi/ 11 psi/ 20,5F/psi
11 C/psi/ 12 psi/ 20 F/psi
10,5C/psi/ 13 psi/ 19 F/psi
10 C/psi/ 14 psi/ 18,5F/psi
10 C/psi/ 15 psi/ 18 F/psi
9,5 C/psi/ 16 psi/ 17,5F/psi
9 C/psi/ 17 psi/ 16,5F/psi
9 C/psi/ 18 psi/ 16 F/psi
8,5 C/psi/ 19 psi/ 15,5F/psi
8,5 C/psi/ 20 psi/ 15,5F/psi
8 C/psi/ 21 psi/ 15 F/psi
8 C/psi/ 22 psi/ 14,5F/psi
8 C/psi/ 23 psi/ 14 F/psi
7,5 C/psi/ 24 psi/ 13,5F/psi
7,5 C/psi/ 25 psi/ 13,5F/psi
7 C/psi/ 26 psi/ 13 F/psi
7 C/psi/ 27 psi/ 12,5F/psi
7 C/psi/ 28 psi/ 12,5F/psi
6,5 C/psi/ 29 psi/ 12 F/psi
6,5 C/psi/ 30 psi/ 12 F/psi
6,5 C/psi/ 31 psi/ 11,5F/psi
6,5 C/psi/ 32 psi/ 11,5F/psi
6 C/psi/ 33 psi/ 11 F/psi
6 C/psi/ 34 psi/ 11 F/psi
6 C/psi/ 35 psi/ 10,5F/psi
6 C/psi/ 36 psi/ 10,5F/psi
5,5 C/psi/ 37 psi/ 10 F/psi
5,5 C/psi/ 38 psi/ 10 F/psi
5,5 C/psi/ 39 psi/ 10 F/psi
5,5 C/psi/ 40 psi/ 9,5 F/psi
5,5 C/psi/ 41 psi/ 9,5 F/psi
5 C/psi/ 42 psi/ 9,5 F/psi
5 C/psi/ 43 psi/ 9 F/psi
5 C/psi/ 44 psi/ 9 F/psi
5 C/psi/ 45 psi/ 9 F/psi
5 C/psi/ 46 psi/ 8,5 F/psi
5 C/psi/ 47 psi/ 8,5 F/psi
4,5 C/psi/ 48 psi/ 8,5 F/psi
4,5 C/psi/ 49 psi/ 8,5 F/psi
⁸4,5 C/psi/ 50 psi/ 8 F/psiView attachment 9169
4,5 C/psi/ 53 psi/ 8 F/psi
4,5 C/psi/ 54 psi/ 7,5 F/psi
4 C/psi/ 55 psi/ 7,5 F/psi
4 C/psi/ 58 psi/ 7,5 F/psi
4 C/psi/ 59 psi/ 7 F/psi
4 C/psi/ 63 psi/ 7 F/psi
3,5 C/psi/ 64 psi/ 6,5 F/psi
3,5 C/psi/ 70 psi/ 6,5 F/psi
3,5 C/psi/ 71 psi/ 6 F/psi
3,5 C/psi/ 75 psi/ 6 F/psi
3 C/psi/ 76 psi/ 6 F/psi
3 C/psi/ 77 psi/ 6 F/psi
3 C/psi/ 78 psi/ 5,5 F/psi
3 C/psi/ 86 psi/ 5,5 F/psi
3 C/psi/ 87 psi/ 5 F/psi
3 C/psi/ 91 psi/ 5 F/psi
2,5 C/psi/ 92 psi/ 5 F/psi
2,5 C/psi/ 96 psi/ 5 F
On my Santa Fe, the tyre data plate states 33 psi with just the driver. 4 pax and luggage, 33 psi. But then handbook states if towing add 2.5 psi.I open my car door and read what is on the plate stuck there, winter or summer gets the same pressure, not had a problem yet.
Or firkins, kilderkins and barrelsbeer is in pints!