Ad below navbar

Collapse

Announcement

Collapse
No announcement yet.

Tyre Pressures - again

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Tyre Pressures - again

    Sorry to ask the old question again

    I have the stock standard tyres on the SWB R model

    ie Bridgestone Duelers D840 265/65/r17 (I could not afford the $1000 they asked to change over to another tyre when I got the car)

    Just got around to checking the tyre pressure

    This was a cold reading but the tyres are at 40-41psi all round. The guage I used is not a cheapy so is believable.

    I rang the dealers and they reckon that is about right for both on road and offroad (but not sand)

    According to the label on the door this with in the specs if towing (ie 3 bar for the back- they are using metric).

    So looks OK for road but I would be interested in what other people are using for these tyres in the various elements
    ie
    Bitumen
    Sand
    Rough dirt with lots of rocks (eg Oodnadatta)
    Other?

    I know it is an oldy but it is a goody and always of interest.

    Rich

  • #2
    41psi is high for a passenger construction tyre (normally 35psi maximum pressure) - check the side wall of the tyres and check the maximum pressure and lower by 2 to 4psi (ie run at 30 to 32psi).

    I know the Pajero I was supplied brand new had 42 to 50psi in the tyres (passenger construction) and was rough as all bugger to ride in - lowed down to about 30psi and was good.


    Black top - >32psi
    Good dirt - 32psi
    Bad dirt - 24psi
    Sand - 14 to 18psi
    --
    Marquis
    SOLD - NT MY10 DiD, ARB D/Bar, Airtec, LRA 81L, Bil/Lov 2", BCDC1220+AGM, P3

    Comment


    • #3
      I have had 3 pajeros and I run them at 40 PSI normal or she steers like a drunken sailor at the helm of a barge, the caveat being that the ride is a little rough
      Dan C; Stock NS Exceed DID Auto w T'bar, Magellan Explorist XL w DAST topo, Tom Tom One

      Comment


      • #4
        Thnaks for the replies.

        I was suprised when I saw it was 40 psi - the reason I rang a Bridgestone dealer and posted the thread, can't beat real experience.

        On the label on the door where it tells you the tyre pressures to use it does say
        F2.6 bar (front) and 3.00 bar (back) while towing so the tyre must handle it but does seem high, so appreciate all comments. I do plan to tow very soon so will reconsider.

        I may drop to 35 and see how that goes for awhile. I need to also test after ruinning awhile to see if increases or not.


        I would be relunctant to go on some rough stoney road with 40 - while towing though.

        Rich

        Rich

        Comment


        • #5
          I run 35 on my passenger construction Cooper AT/R's - a good compromise between comfort and increased tyre life. 40 is too much.

          I also run 26-28 off road on corrugated gravel/dirt. In the sand 18-20, haven't had to go below this with the Paj yet.

          These are cold pressures too....they'll increase as the tyres warm up so check em while they're cold.
          NS GLX DID Auto, MM alloy bar, Kings Springs 35mm Lift, Polyairs, Cooper ATR Tyres 265/70/17, Spider chip.

          Comment


          • #6
            Wilmo,
            Good point - in another vehicle I was running around 32-36 and after many hours driving in very hot weather they were pushing 40+ psi. This was with COOPERS SLE.

            I ended up getting a puncture with the tyre being sliced and only went off road to see a monument (100 meters) and when I drove in to the caravan park at Woomera.

            I will remeasure again with a different guage - to be sure and will drop to 35 psi if still 40.

            Many thanks to all,
            Rich

            Comment


            • #7
              Originally posted by Wilmo View Post
              I run 35 on my passenger construction Cooper AT/R's - a good compromise between comfort and increased tyre life. 40 is too much.

              I also run 26-28 off road on corrugated gravel/dirt. In the sand 18-20, haven't had to go below this with the Paj yet.

              These are cold pressures too....they'll increase as the tyres warm up so check em while they're cold.
              Yesterday we headed for the East Leichardt Dam for a look {30Klm's from Mt.Isa} When we hit the rough rocky dirt road I decided to let my tyres down to 28Psi. I put my Pressure gauge on first & it read 40Psi, first time I had tested my pressures after a short highway run, they had increased by 4Psi & it was only 35 degrees.

              Worth a check when traveling in summer, Didn't think it would increase so much.
              Dual Battery
              80Ltr Waeco
              91Ltr Longrange Tank
              3" Lovells/Bilstein
              3” Exhaust
              Winch
              NP 05 DID

              Comment


              • #8
                A 10% increase in pressure with road driving is quite normal.

                They'll increase by more if they are flexing whilst semi-deflated off road. Flexing generates a lot of heat.
                NS GLX DID Auto, MM alloy bar, Kings Springs 35mm Lift, Polyairs, Cooper ATR Tyres 265/70/17, Spider chip.

                Comment


                • #9
                  Originally posted by Garygls View Post
                  Yesterday we headed for the East Leichardt Dam for a look {30Klm's from Mt.Isa} When we hit the rough rocky dirt road I decided to let my tyres down to 28Psi. I put my Pressure gauge on first & it read 40Psi, first time I had tested my pressures after a short highway run, they had increased by 4Psi & it was only 35 degrees.

                  Worth a check when traveling in summer, Didn't think it would increase so much.
                  A 4psi increase from cold to hot is about what you want to see. I means that, for your particular combination of tyres / load / road / speed, your (cold) tyre pressures are pretty much correct.

                  If you don't get a 4psi increase your pressures are too high, and you'll wear the centre of your tread. If your pressures are increasing more than 4 psi then something isn't right; given that you're unlikely to be able to change your tyres or your load in a hurry, you should either increase your pressures, find another road, or reduce your speed.
                  NT Platinum. DiD Auto with 265/70R17 ST Maxx, Lift, Lockers, Lockup Mate, Low range reduction, LRA Aux tank, bull bar, winch, lots of touring stuff. Flappy paddles. MMCS is gone!

                  Project: NJ SWB. 285/75R16 ST Maxx, 2" OME suspension, 2" body lift, ARB 110, 120l tank, bullbar, scratches, no major dents. Fully engineered in SA. NW DiD & auto in place - a long way to go....

                  Scorpro Explorer Box

                  Comment


                  • #10
                    Originally posted by Garygls View Post
                    Yesterday we headed for the East Leichardt Dam for a look {30Klm's from Mt.Isa} When we hit the rough rocky dirt road I decided to let my tyres down to 28Psi. I put my Pressure gauge on first & it read 40Psi, first time I had tested my pressures after a short highway run, they had increased by 4Psi & it was only 35 degrees.

                    Worth a check when traveling in summer, Didn't think it would increase so much.
                    A 4psi increase when hot is normal. Indeed that is the rule of thumb when trying to find out the correct pressures to run.

                    Start at a given pressure, drive till the tyres are warmed up (at least 20-30K),measure pressure. If the increase is 4psi then you have the correct starting pressure for your car/tyre combo. Less than 4psi means your starting pressure is too high, more then 4psi then your starting pressure is too low.

                    Cheers...
                    Cheers, John.
                    LC200 V8 goodness

                    MY12 LC200 GXL 4.5Lt V8 twin turbo, GVM upgrade, ARB bar, Warn winch, Outback Acc rear bar and dual carrier, TJM sidesteps, Bushskinz, Long Ranger 180Lt tank, Black Widow drawers, cargo barrier, Polaris Awning, +++
                    Ex - NM auto, 2"Kings, Bilsteins, Buckshots, Wildcat headers, 2.75" Mandrel bent exhaust, Injected LPG, Smartbar, Scraper bar, Bushskinz, Custom steps, Dual Batteries, Breathers, Black Widow drawers, Polaris Awning.

                    Comment


                    • #11
                      My tyres were delivered with 45psi in them from the dealership. Mine is an X so it has the 18" rims though - not sure if that makes a diff.

                      Time to let them down a bit I think...
                      NS Shortie, Petrol Guzzler, Tow-Bar, Nudge-Bar, Rear Diff Lock, Rhino Sports roof bars, Newbee 4x4 Driver.

                      Comment


                      • #12
                        That does seem rather excessive. I don't have the manual in front of me - but I believe the pressure for the LWB is only 2 bar, which according to the conversion widget on my Mac, tells me that equates to less than 30 psi (but this seems too low). I have 36 psi in mine, which is what it came with. I only checked them yesterday after 7 weeks - forgot to do on the last tank fill - and I'm only filling every 3.5 weeks at the moment, and my left hand front was down at about 31psi - and although I've only done 5000 km all up so far, I think there is evidence of the outer edges of the tyre (both sides of the tyre) having a tad more wear than the middle - which suggests to me that it has been under inflated at 31psi. I am running standard Dunlop Grandtrek AT 18 inch 265x60 tyres that came with the car when I picked it up in May, and this tyre wear certainly makes me doubt the 2 bar value (interesting that there is no psi value to be seen in the manual). I'll stick with 36 psi and see what happens with tyre wear as the kms pick up.
                        Mar07 build NS LWB VRX Auto

                        Comment


                        • #13
                          Originally posted by mrbitchi View Post
                          A 4psi increase when hot is normal. Indeed that is the rule of thumb when trying to find out the correct pressures to run.

                          Start at a given pressure, drive till the tyres are warmed up (at least 20-30K),measure pressure. If the increase is 4psi then you have the correct starting pressure for your car/tyre combo. Less than 4psi means your starting pressure is too high, more then 4psi then your starting pressure is too low.

                          Cheers...
                          A friend a few weeksago told me about the tyre pressure increase, at the time he was told to go for a short drive & recheck them but their was no change { that was only around town}. He was their on Saturday when I pressure tested mine before deflating.

                          This is worth knowing cause tyres aren't cheap & to keep them at the right pressure I should get a few more Klm's out of them.

                          Thanks all, for your info. Gary
                          Dual Battery
                          80Ltr Waeco
                          91Ltr Longrange Tank
                          3" Lovells/Bilstein
                          3” Exhaust
                          Winch
                          NP 05 DID

                          Comment


                          • #14
                            hey all .... i got mine delivered 8500kms ago at 36psi .... about 500kms ago i went to 39 and got better fuel economy and no problems so far.

                            fingers crossed

                            Comment


                            • #15
                              Hi I started thinking of tyre pressure while towing - ( I have posted recent questions etc)

                              I did a search and found an old thread I created which had some good advice.

                              However the one bit that I am still not sure is what pressure are people putting in the back when towing in offroad conditions.

                              Another question is what do they put in the camper - I think the same as the car.

                              I have LT on the camper and may get AT on vehicle but at the moment they are stock.


                              Richard

                              Comment

                              Matched content

                              Collapse
                              Working...
                              X