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Dueler 697 LT pressure

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  • Dueler 697 LT pressure

    Iíve just had four new Bridgestone Dueler 697 A/Tís fitted in 116S LT spec, 265/65/17 size.

    The Bridgestone fitters have set them to 40psi but the guy said theyíre actually supposed to be at 50. On the tire wall it has 65psi. Theyíve put them to 40 for comfort reasons but the guy even said he has the same tires and heís been running at 40 and theyíre wearing badly and unevenly, but in his ute 50psi was too high without the weight at the back.

    Iím wondering if any other fellow dueler owners can tell me what pressures they run on bitumen. Normally Iíd go with official recommendations - so up to 50psi - but would appreciate some other opinions first.

    Also if anyone has experience with beach driving Iíd love to hear what psi to use for that. The guy reckoned 25-30psi, which was well above my expectations of 18-20, and Iím going beach driving next week so donít want to stuff it up!

    cheers!

  • #2
    Hi Snouto, I also recently purched the same tyre's (Bob Jane's) and was also recommended 40psi as the best for promoting even tyre wear and good ride.
    Have a look at an earlier post on 2nd April re: BFG trye pressures, the guys have some great info on calculating optimal tyre pressures. I will be doing the cals to see how it shapes up.

    Cheers Eddie F

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    • #3
      Originally posted by EddieF View Post
      Hi Snouto, I also recently purched the same tyre's (Bob Jane's) and was also recommended 40psi as the best for promoting even tyre wear and good ride.
      Have a look at an earlier post on 2nd April re: BFG trye pressures, the guys have some great info on calculating optimal tyre pressures. I will be doing the cals to see how it shapes up.

      Cheers Eddie F
      Cheers Eddie, whatís strange is that the Bridgestone select bloke said they should be at 50psi, and that his tired on his ute had chopped up at 40psi. Obviously I donít want my tires going the same way so will be interesting to check out that thread you mention, thanks!

      Following that other thread you mentioned I've used the calculation in the PDF to work out the ideal pressure should be 34.5psi. This is using the Toyota kerb weight for the Prado rather than actual figures, so that will probably change once I can get an accurate weight measurement myself. Still, that's a decent amount below even what the Bridgestone guys put in my new tires. Guess I should try to find somewhere to weigh my Prado before changing anything

      edit 2: using actual weight bridge figures the calcs show a psi value of 38.4, which is much closer to the pressure they put in the tires. I still donít get where putting in 50psi comes from though.
      Last edited by Snouto; 21-04-2019, 11:30 PM.

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      • #4
        I recommend monitoring the pressure change in use, anymore than 4 psi change after a long drive means too low a cold pressure, less than 4 means too high.
        I find that works on bitumen, dirt road/tracks & beach. Higher speeds generate more temp therefore a greater pressure increase, as such loaded highway pressures need to be higher to start with, driving say the Birdsville track I drop my pressure but only cruise at 80 km/hr.
        Over time you will learn what works for you as different tyres & use needs different pressures, that is LT vs passenger construction, tread pattern, vehicle load etc. I found my LT Bridgestones worked better 2 psi less than the same tyre with the standard carcass due to the less sidewall flex.
        02 VX, Toyota Alloy Bar, IPF 900XS with 50 watt HID, 50 mm Lift- Lovell Shocks n Springs, Safari Snorkel, large Pioneer tray, Pioneer In-dash, Alpine roof mount DVD screen -handled the Simpson and Innaminka roads, now with a little TRD blower & Unichip

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        • #5
          Thanks Leethal,
          Good advice I will give it a try.
          Just from curiosity
          I just got back from a 700km trip (all blacktop of varying grades).
          tyres at 40psi. First drive with the new tyres, so knocked all those rubber hairs off the tread, except the ones on the outer tread edge. Assuming the tread should sit fully flat on the road, can I assume this as a good indicator 40psi is too high?

          Eddie F

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          • #6
            EddieF Out of interest did you do the pressure calculations and if so, what figure did you arrive at?

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            • #7
              Hi Snouto,
              Yes did a calc based on one of the methods on the 2nd April post (after weighbridge used to get initial axle weights).

              May have made a mistake on the data as 30 - 31 psi seems quite a bit lower than the recommendation (although the initial tread wear seems to indicate that 40psi is perhaps too high)

              Front Axle 1160
              Rated tyre load 1250
              Max pressure 65
              Est Tyre pressure 30.16

              Rear axle 1200
              Rated tyre load 1250
              Max pressure 65
              Est Tyre Pressure 31.2

              Cheers

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              • #8
                40psi is at the upper end of what you may need, 50psi is ludicrous. Try this guide: http://users.tpg.com.au/klgreen/WK2_...re%20Guide.pdf

                Edit: I see I've already been beaten to posting that link!
                Last edited by Peterpilot; 02-05-2019, 08:55 PM. Reason: Snauto beat me to it!
                "S[FONT=Arial]ure itís quiet, for a diesel. But thatís like being well-behavedÖ for a murderer."[/FONT] [FONT=Arial]- Jeremy Clarkson[/FONT]

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                • #9
                  I've been running Duellers for years, never less than 45psi cold on bitumen. Car will sing with an even higher pressure, but you'll lose ride comfort.
                  Watch for feathering on the outside edges, Prados love to chew off edges on the steer.
                  Swapping front to rear is the only way to even out the wear.
                  Beachwork, the A/T's have very stiff sidewalls so you can run them 12 to 15psi no problem.
                  In my opinion, anything around 20psi you may as well not bother, leave them at 45.

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                  • #10
                    30psi is way to low! Tyre pressure on bitumen is all about getting the right amount of tyre deformation so that the tyre doesn't overheat which causes wear, and that it keeps its shape especially in an emergency situation where you need to take evasive action. Try going on a skid pan with 30 psi to do an emergency turn and/or braking and then try it at 40 psi. The difference is night and day.

                    Tyre pressure off-road is a completely different scenario with different criteria.

                    I run 46 front and 54 rear on my annual fully loaded long tow up north based on tyre temps and pressure increase, which is the only way to tell how hard the tyre is working.
                    [B]Steve[/B]

                    2010 Silver GXL Prado 150, D4D Auto, with a few non standard bits

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                    • #11
                      It all depends on your tyres and weight, mine are rated to carry 1250kg @ 50psi. If your tyres need 65psi to carry the same weight, then your pressures will be about 30% more. Use the 4psi rule as per the PDF to fine tune the pressure for your particular tyres and weight combo.
                      "S[FONT=Arial]ure itís quiet, for a diesel. But thatís like being well-behavedÖ for a murderer."[/FONT] [FONT=Arial]- Jeremy Clarkson[/FONT]

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                      • #12
                        For what it is worth, my two cents on this subject.

                        36psi when empty and then up to 38psi in the rear when loaded has given me good wear all round. no way would I go up to 50psi.

                        Have been down to 10psi on the beach which was good but kept the speed down. Just did 2 days on Googs at 16psi with no issues. The tyre lengthens when the pressure is dropped as apposed to widening.
                        [B]Tasmania 2015 GTG Committee Member[/B] 2005 Prado Pilbara, Sovereign Bar, Driver & passenger weathershields, UHF TX3220, Spare wheel spaces, Lifestyle rack, Genuine front & midrow seatcovers, Genuine front & midrow rubber floor mats, ARB 47 litre fridge/freezer, Hilux washer jets, BF Goodridge A/T, Radiator protection plate, Dual battery tray and isolator, ARB 2.5m awning, Rhino heavy duty areo bars, MSA rear wheel bin, MAXTRAX

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                        • #13
                          Thanks everyone, Iíve not been back on site for a while so apologies for the lack of reply. In the end by my calcs and weigh bridge values I came to 38psi as the ideal tyre pressure, so thatís where Iíve got them. Ran 20psi when at noosa north shore, seemed to work out fine (although that beach is basically a highway). Will be sure to rotate at service time if required, including the spare that I needed up getting when I saw how bad the existing one was. Itís amazing really, before I had these tires fitted Iíd never had a problem picking up screws from the road but since getting the tires Iíve found two buried in the tread. Thankfully right through the top of the tread at its thickest point and thus removed without issue, but it does make me wonder what would have happened on the old non-LT cheapo tires I had previously.

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                          • #14
                            Spam
                            Last edited by Piggy; 11-07-2019, 04:36 PM.

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                            • #15
                              Getting tyre pressure right achieves two things, prevents excessive heat build up by reducing tyre deformation and optimises tyre wear. It also significantly improves handling.
                              Balanced against all those factors is comfort, since lower pressures increase comfort but also increase wear and heat build up, and significantly effect handling.

                              An under-inflated tyre has a much worse effect on handling than an over-inflated tyre, if you don't believe this go to a skid pan and try it. getting through a chicane on under inflated tyres is near on impossible. Also in the wet under-inflated tyres will aquaplane much more easily than over inflated tyres.

                              So getting pressures right has significant safety implications in improving handling, particularly in emergency situations and in preventing premature and unexpected tyre failure.

                              All the methods described for setting tyre pressure in the link provided above are aimed at establishing the best level of tyre deformation. Interestingly there is no reference for the methods or mention of who the author is in that guide.

                              Short of some very complicated methods to measure the contact patch, the simplest methods for setting tyre pressure rely on measuring tyre heat build-up either directly or through change in pressure (4psi method, which is 5-15% change depending on starting pressure). Pressure and temperature are directly related, so as the tyre temperature increases pressure also increases and this has happened because the tyre has been deforming. The more deformation, the more heat, and the greater the pressure increase.

                              Ultimately the best advice is to use a combination of visual checks, look at how the tyre is sitting and wearing, combined with checls of tyre heat build up and pressure change. For the standard Prado tyres on low loads this seems to give an optimum pressure around 40psi, and up to 50 or so psi for the rear when fully loaded and/or towing.
                              [B]Steve[/B]

                              2010 Silver GXL Prado 150, D4D Auto, with a few non standard bits

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