tire pressure

Discussion in 'Tires / Brakes / Bearings / Axles' started by strutnrut, Apr 29, 2010.

  1. strutnrut

    strutnrut New Member

    Messages:
    40
    Likes Received:
    0
    Joined:
    Apr 20, 2010
    how much air should my 5-30-12 hold c rated tire
     
  2. Twisty

    Twisty New Member

    Messages:
    4,375
    Likes Received:
    4
    Joined:
    Aug 24, 2008
    Location:
    Hillsboro, Oregon
    Re: tire preasure

    It should be molded into the sidewall of the tire along with the size and load rating.
     
  3. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    Re: tire preasure

    the max air pressure is on the tire but the pressure you use depends on the trailer it may be in the owners manulal or on the vin tag on the trailer it depends on the trailer more than the tire just don`t put more air pressure than what is stamped on the tire!!
     
  4. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    12
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    Re: tire preasure



    S.O.P. (standard operating procedure) - is to always go with what is stamped on the side of the tire and for that particular tire would be 80 psi - my size tire, too!
     
  5. strutnrut

    strutnrut New Member

    Messages:
    40
    Likes Received:
    0
    Joined:
    Apr 20, 2010
    Re: tire preasure

    does 80 mean 40pounds it will hold
     
  6. rabird

    rabird Howdy!

    Messages:
    6,747
    Likes Received:
    322
    Joined:
    Mar 3, 2006
    Location:
    TX
    Re: tire preasure

    80 psi means 80 psi.

    Get a tire gauge that goes to 100.
     
  7. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    Re: tire preasure

    flyfisherman what is stamped on the side of the tire is the max the tire will hold that is not the same as what the trailer is rated for just like a car tire you go by what is on the door post and it will always be lower than what is on the tire the same tire can be used on more than car and the tire pressure can change from car to car but just won1t go over what is on the side of the tire!!!
     
  8. Twisty

    Twisty New Member

    Messages:
    4,375
    Likes Received:
    4
    Joined:
    Aug 24, 2008
    Location:
    Hillsboro, Oregon
    Re: tire preasure

    ranger guy,
    you are partly correct.
    Trailer tires should always be inflated to the pressure molded into the tire sidewall.
     
  9. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    Re: tire preasure

    i don`t think that is the way it goes my 2007 jayco 1207 says to set the tire pressure to 65 psi but the tire rating is 80psi !! you always go by the trailer spec not the tire whats on the tire is the max air you can put in the tire!!!
     
  10. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    12
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    Re: tire preasure


    Well, Carlisle Tire, says to go with the max ... if the tire is rated to carry 1,050 lbs at 80 psi, then IT HAS TO HAVE THAT MUCH PRESSURE.

    Besides, the camper's suspension design calls for tires that size, with that much air pressure ... it was made to handle it.

    http://www.carlisletire.com/product_care/trailer_tire_poster.pdf


    Even Dexter Axle's guidelines say to go with the tire manufacter's specs ...


    http://www.dexteraxle.com/running_gear_tips
     
  11. jim1999

    jim1999 New Member

    Messages:
    1,645
    Likes Received:
    2
    Joined:
    Jul 8, 2008
    Location:
    East Central Illinois
    Re: tire preasure

    With the way trailer tires are constructed in order to get their max load carrying capacity as well as to allow them to dissipate heat as quickly as possible and hence get the max life out of them they should be aired up to the max PSI that is stamped onto the tire.

    Car tires are made differently. The reason to air them to the car manufacturers spec instead of the max located on the tire is because of the suspension. A car's tires is an integral part of a car's suspension system and everything has been designed to work best together when using components that fall into a set range of parameters.

    Companies that make trailer tires, be it for utility trailers, camper or large semi trucks have had research going, both in the lab, on test tracks, in the real world for decades trying to figure out the best PSI to run the tires at in order to get the best across the board performance. So far running trailer tires at the max PSI is in the lead across all factors.

    Now if you really want to do something nice for your car and trailer tires fill them with Nitrogen instead of air.
     
  12. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    12
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    Re: tire preasure

    (Those summary maintenance tips from Carlisle Tire once again):

    - Summary Maintenance Tips -
    · Keep your tires air pressure at the Maximum PSI recommended on the sidewall of the tire
    · Keep a cap on your valve stem to prevent contamination of the internal rubber valve
    · Always travel with a spare and check your spare tires air pressure along with the other tires
    · If you experience a blowout, slowly move over to the right off the road to change your tire and check the other tires for
    possible damage
    · Don’t overload your Trailer Tires. The maximum load is listed on the sidewall of your Trailer Tires
    · Give your Trailer Tires a visual check before each trip
    · Keep your Trailer Tires in a cool dry place and out of direct sunlight during storage
    · Replace your Trailer Tires every 3 to 5 years
     
  13. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    Re: tire preasure

    ok if i`m wrong i will addmit but car tires are not set to max and im will allways go with the owner mamual states and that is that!!!
     
  14. Engauge

    Engauge New Member

    Messages:
    140
    Likes Received:
    0
    Joined:
    Jan 11, 2010
    Re: tire preasure

    Ranger Guy....I'm with you. Over inflate a tire and you are asking for problems.

    My tires are not filled to the max pressure stamped on the tire, they are filled to the mfg spec shown on a tag on the trailer frame.

    There was another post I was reading the other day about someone filling the tires to the max and having problems with tire wear.
    http://www.popupportal.com/index.php?topic=35166.msg224302#msg224302
     
  15. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    12
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    Re: tire preasure


    Underinflated a trailer tire and your asking for much bigger problems and kinda fast like. Also, under inflation will also lead to uneven tire wear.

    As already posted, there's a big difference in automotive tires and ST (special trailer) tires.

    I'm curious about that tag on the frame ... what manufacturer is that(?) The reason I ask is neither my Starcraft or the Coleman/Fleetwood I had before had any such tag on the frame saying anything about tire inflation - only about the GVWR, date it was made and the V.I.N. number. But if push came to shove I'll side with the tire manufacturer's recommendations as I bet they know a whole lot more about tires.
     
  16. Engauge

    Engauge New Member

    Messages:
    140
    Likes Received:
    0
    Joined:
    Jan 11, 2010
    Re: tire preasure

    http://www.goodyear.com/rv/pdf/rv_inflation.pdf
    If I read the link correctly it is from Goodyear for ST tires and charts tire inflation based on load. Although it does not reference 12" tires.


    I am not at home right now but will check the details tonight. I do know they are 13 inch tires.
     
  17. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    thanks" engauge" for the support on this one i`m glad someone see`s this the same as i do !!!
     
  18. Storm Trooper

    Storm Trooper Home is where you park it!

    Messages:
    3,544
    Likes Received:
    12
    Joined:
    Feb 14, 2008
    Location:
    Where my camper is parked now.
    I've had 3 Coleman/Fleetwood pups since 1992 and each either had a sticker outside or inside a cabinet with the recommended tire pressure. Fact of the matter is, all of them were at the max tire pressure. Go by what the sticker says first. In the absence of that sticker inflate them to the max tire pressure.
    Unlike autos, pup manufacturers seem to put the minimum tire designed to carry the weight. There is very little extra capacity beyond the pups Gross Weight.
    Load something too heavy on one side and you are over weight for that tire. At that point you need to redistribute your load if possible and run the tires at the maximum pressure to hopefully safely carry the pup.
    How many of you have weighed your pup to find out how close it is loaded to the gross weight? I'll bet not too many have. I keep meaning to, but I haven't . Trailers light weights are notoriously wrong (being much too light).
    In the absence of a recommendation for tire pressure from the pup manufacturer, I'd run them at the max pressure on the sidewall. Make sure that if the tires had been replaced, that they are of the same size and load rating.
    There are too many instances here on the portal of people with blowouts from tires lacking extra capacity or substandard tires. The last thing I would do is underinflate them.

    BTW, putting the ST tire at the maximum pressure is not overinflating them. That is the pressure ST tires are designed to run on.
     
  19. grim509

    grim509 Member

    Messages:
    111
    Likes Received:
    0
    Joined:
    Feb 2, 2010
    Gonna shed some light on this. I grew up with a tire shop in my back yard. Literally. My brother went to one of the top automotive schools in the country. Here's the skinny:

    It is perfectly safe to inflate to max tire pressure on both car and trailer tires. Keep in mind, inflate when it's cool. Yes, pressure will go up when tire heats up as it goes down the road. The tire manufacturers already took this into account when they figured up the max tire pressure to put on the sidewall.

    DO NOT go by what is on your camper's sticker or manual. That is an estimate based on average load. If you load more into your camper, and do not increase the pressure in the tires, you're asking for big problems! The tires are designed and built to run at these pressures. The tire will wear more evenly, it won't get as hot, lasting longer, and it will actually improve gas mileage.

    As far as the auto tires, it's personal choice. But it's still safe to use the max tire pressure. Many mechanics and tire specialists are now recomending it. Remember, when the manufacturer puts the tire pressure in the manual or sticker on the door, that's for the brand of tire they put on the vehicle. Manufactuers have different strengths of sidewalls, wear patterns, tread life etc.

    It's more dangerous to UNDERINFLATE than to run at max pressure. Underinflate can cause a blowout. Max pressure can cause nothing.
     
  20. ranger guy

    ranger guy New Member

    Messages:
    412
    Likes Received:
    1
    Joined:
    Mar 10, 2009
    grim509 just to fill you in, on most new cars now you have to go with what is on the post or you will have the tire monitoring light come on. Most new cars come with the sensors in the rims or it is the valve stem and it you have to much air or low air pressure the light will come on. So if you want a big yellow light on in the dash all the time just use the max tire pressure, not to mention the ride will be harsh.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.