Autosleeper Symbol

Discussion in 'Motorhome Chat' started by Brenda Glanfield, May 15, 2016.

  1. Brenda Glanfield

    Brenda Glanfield Funster

    Joined:
    Jan 31, 2016
    Messages:
    15
    Likes Received:
    2
    Location:
    Birmingham
    Hi everyone,
    I am new to motor homes and everything is slightly daunting at present. I am just about to embark on my first trip and am keen to do all the safety checks before I go.
    Although I have lots of information on my Autosleeper, the advice on tyre pressure seem is to differ greatly.
    Anyone advise?
     
    • Like Like x 1
  2. Bacchus

    Bacchus Funster

    Joined:
    Jul 27, 2015
    Messages:
    423
    Likes Received:
    4,275
    Location:
    Staines
    I am sure someone with autosleeper knowledge will be along to help shortly, but I run my old Hymer on about 65 psi if that's any use...
     
  3. Brenda Glanfield

    Brenda Glanfield Funster

    Joined:
    Jan 31, 2016
    Messages:
    15
    Likes Received:
    2
    Location:
    Birmingham
    Thank you. Handwritten notes that came with the van suggest 44 psi, but that seemed a bit low.
     
  4. Bacchus

    Bacchus Funster

    Joined:
    Jul 27, 2015
    Messages:
    423
    Likes Received:
    4,275
    Location:
    Staines
    I have just had a quick google around and the answer does seem to vary between 44/50 (front/rear) and 60/65.

    the tyres will probably wear quicker at lower pressures but will require higher pressures if you are heavily loaded.

    Sorry that's not a definitive answer but there does seem to be an element of personal preference!
     
  5. Viennese

    Viennese Funster

    Joined:
    May 21, 2008
    Messages:
    2,348
    Likes Received:
    2,532
    Location:
    Oxford
    Phone Autosleeper and ask them, they are very helpful. You may need to specify the year, and somewhere in the van you will find an Autosleeper number which will identify the van. Mine was in the glove compartment.
     
    • Like Like x 1
  6. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    65 rear 60 front.....(y)
     
  7. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    Build number is indeed in the glovebox ..
     
  8. Puddleduck

    Puddleduck Funster

    Joined:
    Jan 15, 2014
    Messages:
    6,478
    Likes Received:
    13,815
    Location:
    Scottish Borders
    It will also depend on weight and the type of tyre.

    We weighed ours and sent the weights to Continental who advised the correct pressure - rather lower than the FIAT tyre pressure sticker but a much better ride with the Continental pressures.
     
    • Like Like x 1
  9. Cavs

    Cavs Funster

    Joined:
    Apr 10, 2010
    Messages:
    245
    Likes Received:
    239
    Location:
    Bedfordshire
    Measure the load on each axle (L). Find out the load rating of the tyres from the code on the side wall (R). Find the maximum pressure of the tyres, also from the side wall (MP).

    The tyre pressures to run at (P) = L divided by R times MP.

    When I've used this formula it has always been bang on what Continental advised.
     
  10. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    Continental may advise on the basis that the van is a chassis cab or van if. PVC.

    So they may give a pressure for all round all weight use or an average of. A motor home is in most cases that chassis or PVC fully loaded all of the time which would result in higher pressures needed. .

    Running incorrect pressures can result in overheating. We should increase the pressures on even our cars if carrying more than one passenger for most of the time.

    Auto sleeper recommend 65 rear 60 front based on the fact the PVC in this case a Symbol is in fact a fully loaded van very nearly all of the time.
     
  11. Cavs

    Cavs Funster

    Joined:
    Apr 10, 2010
    Messages:
    245
    Likes Received:
    239
    Location:
    Bedfordshire
    Continental will want to know the axle weights you run at and will give you the pressures appropriate to those weights and the tyres fitted.
     
    • Like Like x 1
  12. Puddleduck

    Puddleduck Funster

    Joined:
    Jan 15, 2014
    Messages:
    6,478
    Likes Received:
    13,815
    Location:
    Scottish Borders
    That's what I sent them along with the details of the tyres fitted and told them that it was a motorhome. They were very helpful, gave their recommended pressures / temperatures (we have tyrepal) and all is good.
     
  13. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    So long as they take in the vehicle will be fully loaded most of the time then fine.

    Take a Peugeot van. 3500 GVW but that van will be at max load for only some of the time. The works vans we have are hardly ever loaded above a third of the possible weight carrying capacity. If they were fully laden the tyre pressures would need to be far higher.

    The same van converted into a motor home is quite different .

    If the tyre manufacturers are in full posesion of the info they will likely draw the same conclusion as Auto Sleeper and set them 65/60 as AS do.

    AS are in full posesion of the facts as they build the vehicles. Personally I go with the vehicle builders .
     
    Last edited: May 15, 2016
  14. John Laidler

    John Laidler Funster

    Joined:
    Jan 9, 2013
    Messages:
    8,586
    Likes Received:
    11,574
    Location:
    Plympton, Devon
    I don't agree, the vehicle manufacturer can only give general recommendations which in the case of Fiat seem to be very high pressures. The tyre manufacturer, if they know the axle load, which will reflect precisely the loading on the tyre, should know the best pressure to run them at. However, the only manufacturer who seems to make this advice readily available is Continental but other manufacturers should respond if asked.

    The pressures shown on sidewalls are the maximums and in most cases you can run at much lower pressures perfectly safely, but of course it really does depend on the axle loads and unless you take your vehicle to a weighbridge you won't know what those are.

    I've now done around 10K miles on mine running them at 3 bar front, 3.25 bar rear on a 3.5t PVC with Continental Vanco Four Season tyres. There is no sign of uneven wearing and they don't overheat. Whenever I take it in for a service I have to let the tyres down afterwards as they blow them up to 5 bar - because that is what the handbook says.

    In summary, know your axle weights and then ask the tyre manufacturer. Otherwise, follow the handbook and prepare to replace your fillings regularly. :)
     
    • Like Like x 2
  15. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    I'm not saying eithe vehicle builder or tyre maker is wrong or right merely that the vehicle builder will know the real weight of the vehicle and that it is at that weight most of the time.

    It could be I am by taking note of AS am running way to high with my pressures.

    This my friend is why we debate. (y)
     
  16. Cavs

    Cavs Funster

    Joined:
    Apr 10, 2010
    Messages:
    245
    Likes Received:
    239
    Location:
    Bedfordshire
    My vehicle has just come back from main dealer service with tyre pressures around 62 psi all round. The maximum pressure marked on the tyres is 83 psi (Continental Vanco Four Seasons). The calculation above and Continental give pressures of 58 psi front and 47 psi rears. As DBK says, always let the tyres down after service!

    The axle loading you have to use is the one that you run at - in my case fully loaded at 2,100 kg front and 1,800 kg rears.
     
    Last edited: May 16, 2016
  17. matamoros

    matamoros Funster

    Joined:
    May 15, 2008
    Messages:
    2,280
    Likes Received:
    3,445
    Location:
    Ex Rochdale now Tavira, S. Brittany & Europe
    What units do you use in this formula, psi/bar.......kg/lbs?
     
  18. Cavs

    Cavs Funster

    Joined:
    Apr 10, 2010
    Messages:
    245
    Likes Received:
    239
    Location:
    Bedfordshire
    It doesn't matter as long you're consistent. The tyre load rating is in kg, so I use that, but I often switch between psi and bar.

    An example for my front axle: L 2,100 kg; R 2,900 kg; MP 80 psi.
    2,100/2,900*80 = 58 psi.
     
    • Thanks Thanks x 1
  19. matamoros

    matamoros Funster

    Joined:
    May 15, 2008
    Messages:
    2,280
    Likes Received:
    3,445
    Location:
    Ex Rochdale now Tavira, S. Brittany & Europe
    Thanks for that, I was going to experiment but you saved me the trouble:)
     
  20. Charlie

    Charlie Funster

    Joined:
    May 16, 2015
    Messages:
    2,244
    Likes Received:
    2,612
    Location:
    Herefordshire / Worcestershire borders .
    Must admit to sticking to the book specifications ! Looks like I've been running with too high pressures !
     
Loading...

Share This Page