Outline · [ Standard ] · Linear+ Pressure in tyres during hot, hot days..., Should pressure be increased?

Should tyre pressure be increased during long trips (highway) during those very hot summer days (most of the Balkans now have daily air temperatures around 40C, while temperature at the asphalt is more than 60C - as it is "melting" already... ). And if yes, to what pressure? (talking about standard Barum 14" tyres that came with Logan). Also, if unable to check the pressure of the tyre when tyre is not hot (nearest gas statin is 5-6 km) is it true that some 0,2 Bar should be added as that is the difference between the pressure of hot and cold tyres (and manufactorers specification always specifies cold tyres)

Should tyre pressure be increased during long trips (highway) during those very hot summer days (most of the Balkans now have daily air temperatures around 40C, while temperature at the asphalt is more than 60C - as it is "melting" already... ).

And if yes, to what pressure? (talking about standard Barum 14" tyres that came with Logan).

Also, if unable to check the pressure of the tyre when tyre is not hot (nearest gas statin is 5-6 km) is it true that some 0,2 Bar should be added as that is the difference between the pressure of hot and cold tyres (and manufactorers specification always specifies cold tyres)

Never deflate a hot tyre.
I for one would decrease pressure on such a hot day, because with atmospheric temperature and the hot asphalt the pressure in the tyre would rise to a dangerous value. Also, a slightly deflated tyre would have a larger footprint and thus lower ground pressure, limiting the damage done to the hot and soft asphalt (the opposite is the case for high pressure in the tyre)

http://www.thetyrepressuremonitor.com/

This post has been edited by martin245: 22 Jul 2007, 21:35

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einstein, what you suggest is more than dangerous and could cost lifes - where the h.... did you get this totally wrong opinion from?

suggest you check with tire and car manufacturers first. all of them will tell you how dangerous an under-inflated tire is.

driving a few kms at normal speed to a gas station will not yet make it a 'hot' tire. what manufaturers warn against when
talking about measuring on a hot tire is somebody who has driven 140++kmh for an extended period, and then
measuring (german autobahns, for example). such a tire can be so hot you burn your fingers on it.

greetings - heinz -

This post has been edited by heinz57g: 24 Jul 2007, 10:02

The correct pressure on logan tyres is 2.0 Bar front and 2.2 Bar rear when the tyres are cold.
You have it written on driver's door.

On these hot days our forum colleague Kojak found the pressure after running on hot roads to be 2.4 Bar front and 2.6 Bar rear. The pressure was correct 2.0/2.2 in the morning with the tyres cold.

So the increase could be up to 0.4 Bar in those hot days.

i know for us in europe this is exceptional, but pls note that there are many countries in africa and asia where standard temperatures
are well over 40C, every day! and many of them have even worse roads then we have (yes, eastern europe included).

as strange as it might sound to us, but they usually do not raise the tire pressure, or if they do, by 0.2 bar only.

in principle, raising by 0.2 or even 0.4 does not go anywhere near the tire limits, and has other advantages too. it is definately much
safer than even 0.2 bar below normal.

greetings - heinz -

As I read on the Dacia site the new value of pressure increased with 0,2 bar

Can you tell us new (end of 2007) values for tire pressure?

According to my manual for 185/65/R15 is 2.0 for front and 2.2 for rear tires.
According to old "Manual De Service Dacia Logan.pdf" is

Presiune de umflare în utilizare normala (în bari)
Fata Spate
5,5 J 14 165/80 R14 2 2
6 J 15 185/65 R15 1,9 2,1
6 J 15* 185/65 R15 1,9 2,1

Hello guys,

at some point in time I performed some calculations on this issue. I had posted the results here on the Forum but they were deleted. Anyway:

1. the correlation pressure/temperature is NOT linear
2. The magnitude is about 0.1 bar per 10 degrees Celsius, depending on factors as the initial inflating pressure of the "cold" tyre; "cold" temerature (is it 0 degree like in winter, is it 30 degrees as would be in summer prior to driving).
3. Personally I tend to use ppressures at the upper end of the scale - so I normally add like 0.2 bar unually.
4. I do not think that one should care too much about the issue of the higher temps in summer - since the "cold" temp will also be higher. More important is finding a oressuregauge that's precise and repeatable enaugh.
5. However in some conditions it could be (inflating to the limit) that the pressure in a warm type exceeds the normal "limit". E.g. Tyre sais Max Inflation. 3 bar; one puts 2.8 into the tyre then drives so the tyre heats 40 degrees -> 2.8+0.4 = 3.2 bar.