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Tyre pressure

Discussion in 'Tyres & Alloys' started by Chaos, Jun 1, 2010.

  1. Chaos

    Chaos Regolare

    In my opinion, 32 - 34 psi should be the benchmark for almost any variant (Punto/linea) throught the year :car

    IN ALL 4 TYRES.

    32 psi when tyres cold.
    34-36 psi when tyres warm to HOT (highway run)

    But again, from my experience the pressure to be maintained keeps changing from season to season..
    So this is my list suitable for both city / highway run:

    Winter/Rainy Season: 32psi (cold tyres)
    Summer: 32-34 psi (city) (cold-warm tyres) ~~~~ 36 psi (highway) when the tyres are already hot from running.

    SPARE: 32 - 34 psi [depending on cold/hot weather (boot temp below the mat)]

    Suggestions:
    Please check air at a reliable electronic machine. Some petrol pumps have a defective nozzle..
    Avoid analog gauges for accuracy.
    NO nitrogen. Reviews suggest a bumpy ride.
  2. VahanPujari

    VahanPujari Staff Member Janitor

    Messages:
    2,303
    Mumbai
    :nicethread
    Here is the relevant (progressive) experience from my Linea ownership report:

    (I think warm tyre condition means even after a running of 1 km)

    Long Post... :-D :mrgreen:
  3. Pran

    Pran Superiore

    Messages:
    748
    Bangalore
    Grande Punto 1.3
    32 psi for the front and 30 psi for the back tyres suits my requirement. Most of the time back seats are empty so there is no point in inflating the back tyres with the same pressure as in front. I tried with 34 psi but I felt its not good for the large potholes in my city :A
  4. johnny

    johnny Regolare

    Messages:
    437
    Greater Noida
    Greater Noida
    Grande Punto 1.3
    About nitrogen filling: It is used in fighter aircraft tyres. The main reasons are: lesser leak rate, does not react with tyre material being an inert gas, & fire resistance. The last reason becomes important when you consider that a MiG-21 lands at a speed of 300 kmph. The aircraft weight is close to 6.5 tonnes, and you have about 2 to 2.5 km of runway to stop the aircraft. The wheel assemblies get VERY hot at the end of the landing roll. If compressed air is used, the tyres could catch fire.
    The ride quality of nitrogen filled tyres should not be any different from air filled tyres. I do not think the use of nitrogen in passenger car tyres is really warranted.
    Johnny
    Saurabh Gharat likes this.
  5. Chaos

    Chaos Regolare

    Johnny, Nitrogen as a gas has different physical properties than air. Agree??

    Many who have filled nitrogen have either complained the undercarriage scrapes every bump (less pressure) or a bumpy ride (excess pressure)

    It basically takes trial and error. and the pressure to be maintained when using nitrogen is not same that of when using air. It takes experimentation.

    AFAIK, The use of nitrogen was discussed at google group, and our member ended up with a bumpy ride.. and we concluded that it was better to use air, than nitrogen.
  6. rameshjoshi

    rameshjoshi Amatore

    Messages:
    62
    Pune
    I am a little confused. Should tyre pressure increase when it is hot? Shouldn't we use less pressure e.g. 30 for summers? Why 34/36?
  7. Chaos

    Chaos Regolare

    during the cold season when you fill 32 psi in cold tyres. after checking on normal running, the tyres warm up to 34 -36 psi.

    In summer, by the time you reach the pump to check tyre pressure, the tyre warms up 1-2 psi. so the reason to fill extra on as cold tyres as possible.

    BTW, 32 psi in winter on cold tyres warms up to 38 psi on a afternoon highway run. and in the city after a check the pressure rises upto 34-36 psi.

    In summer if you fill 34 psi for a city run, after a check the pressure will hover around 34- 36 psi. This is because by the time you reach the pump, the tyres get little warmer than it does during winter.
    The end aim is to maintain the pressure to optimum condition as possible. It is completely dependent on a cold Tyre.
  8. VahanPujari

    VahanPujari Staff Member Janitor

    Messages:
    2,303
    Mumbai
    ...Normal Air contains 78% of Nitrogen :mrgreen:
    1 person likes this.
  9. Rev Happy Turbo

    Rev Happy Turbo Novizio

    Messages:
    39
    Mumbai
    so in other words you dont get the actual nitrogen gas? an adulterated gas? :wow

    just duped of your extra money??
  10. @VP : Is it not the other way round?
    Normal air that we fill already contain 78% Nitrogen
    And, what we get in specific "Nitrogen filling stations" is 100% Nitrogen. (or may be whatever is theoretically/possibly closer to 100%)

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