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tire pressure for 39.5's

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Blue Meanie, Apr 12, 2002.

  1. Blue Meanie

    Blue Meanie Registered Member

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    tire pressure for 39.5\'s

    i am running a set of 39.5x15x15 tsl's on 10x15 rock crawler rims. i saw in one of the offroad mags that they are running 42's at 20 psi on the highway. i am running mine at 20 psi also, but am scared of a blow out. what tire press should i run to avoid this or is 20 going to be enough?
     
  2. zakk

    zakk 1/2 ton status

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    Re: tire pressure for 39.5\'s

    i run 17psi...
     
  3. Blue Meanie

    Blue Meanie Registered Member

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    Re: tire pressure for 39.5\'s

    17 with no problems?? how about the wear and how long are the drives to the trails? the places we have in NJ are about an hour away. is that an ok time to drive on them at 60-70mph?
     
  4. zakk

    zakk 1/2 ton status

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    Re: tire pressure for 39.5\'s

    i drive mine every day to work, to skool, to the shop, etc. I dunno, i PERSONALLY have had no problems, i don't know how you drive, etc. I don't go faster than 65mph, and I have no sway bar or steering stabelizer, so i take it easy in cornors too.
     
  5. Blue Meanie

    Blue Meanie Registered Member

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    Re: tire pressure for 39.5\'s

    right on. i still have the sway bar but no stabalizers because of the rockram. i just wanted to poll the population to see what their recomendations are. i haven't had problems either but wanted to ask because 20 seems low to me. thanks
     
  6. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    Re: tire pressure for 39.5\'s

    You have to remember you are riding on balloons. Think about ATV tires because they are soo wide for the ATV and tough it takes like 3-5 psi to fill them. Not to mention it keeps them a little flexy to absorb rocks, stumps, etc. Its not the actual air in the tire that suports the weight of the truck but rather the strings in the sidewall. As long as there is sufficent air to keep the strings tight the tire is properly inflated. SO it could really only take 17-20 psi to have a tire that large properly inflated and getting the proper tread wear. 35 psi like in smaller tires would have you riding on a thin patch in the center of the tire. You might always try the reoccuring trick mentioned. Wet a small patch on the driveway, back through it and looking at the marks left you can tell the tread contact being made, If not enough deflate if too much inflate....
     
  7. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Re: tire pressure for 39.5\'s

    It would be my guess that a 39.5" TSL would leave a great footprint on the driveway at 3 psi...I'd start at 25 psi and try the water or chalk method and keep dropping the pressure til it looked good.

    Rene
     
  8. BowtieBlazer

    BowtieBlazer 1/2 ton status

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    Re: tire pressure for 39.5\'s

    Yeah any tire will at 3 PSI /forums/images/icons/smile.gif
     
  9. zakk

    zakk 1/2 ton status

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    Re: tire pressure for 39.5\'s

    well at 5psi it was great till the tire rolled of the wheel/forums/images/icons/laugh.gif

    *zakk still needs 16.5 beadlocks*
     
  10. Blue Meanie

    Blue Meanie Registered Member

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    Re: tire pressure for 39.5\'s

    yeah, i heard that tsl's don't hold up too well to anything less than 10 without bead locks. thanks for the help.
     
  11. pcorssmit

    pcorssmit 1/2 ton status

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    Re: tire pressure for 39.5\'s

    Never messed with the pressure on mine too much, generally it seemed to drive best at 30 psi on the street (IIRC, the max for these tires). Mine are 15"s. I run about 7 off road, w/beadlocks. Need bigger tires now, though.

    Pete
     
  12. Blue Meanie

    Blue Meanie Registered Member

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    Re: tire pressure for 39.5\'s

    i know the feeling. i just bought these and i want bigger ones too, or a set of boggers. the only problem is my wife, she would kill me!!!!!
     

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