Tyre Pressures

dinglebin
dinglebin Forum Participant Posts: 47
edited July 2016 in New to Caravanning & Touring #1

Hi, Can anyone comment on the tyre pressures being quoted on this on line swift handbook which I've found for my Swift Charisma 560.  The link suggests that the pressures should be 65psi.  This seems really high and I'm nervous about putting that much air
in them.

https://assets.swiftgroup.co.uk/uploads/HandBooks/caravans/2008 Tourer Tech Books/2008 Charisma Tech Handbook.pdf

Comments

  • Simon100
    Simon100 Club Member Posts: 666 ✭
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    edited July 2016 #2

    My lunar clubman, single axle, is also 65 psi.

  • kaenergas
    kaenergas Forum Participant Posts: 171
    edited July 2016 #3

    I have a Sterling Elite Amber, tyre pressures also 65psi, like wise when I bought this caravan from new I questioned the pressure but it's correct. I suppose when you look at the weight these caravans are on a single axle 2tyres,  Instead of using the underslung
    spare wheel carrier, I keep my spare wheel in the boot, its very heavy wouldnt like to try to get that off the carrier in an emergency.

  • Wildwood
    Wildwood Club Member Posts: 3,581 ✭✭✭✭
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    edited July 2016 #4

    Caravans normally use van tyres that can take the higher pressures so I would not worry.

  • nelliethehooker
    nelliethehooker Club Member Posts: 13,644 ✭✭✭
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    edited July 2016 #5

    Our tyres on a Unicorn Madrid also have a recommended pressure of 65psi. They are classed as "light truck" tyres.

  • jennyc
    jennyc Forum Participant Posts: 957
    500 Comments
    edited July 2016 #6

    Motorhomes often have even higher pressures, which caravan tyres will also take. Under inflated tyres can make towing unstable so it's worth adhering to the manufacturers recommendations.  BTW your tyre pressures are shown on the vans rating plate, which
    may be a better reference than a handbook which is shared between models. Particularly if your van has been re-rated.

  • Nuggy
    Nuggy Forum Participant Posts: 512
    edited July 2016 #7

    You should really be comparing tyre makes and spec, not the make of caravan. The tyres may not be the original tyres.

  • gygafo
    gygafo Forum Participant Posts: 51
    edited July 2016 #8

    I just checked the pressure for my Lunar Ariva GTS 2003, the manual says 36psi which to me looks as though they are under inflated. A search for the tyre size and MTPLM of the caravan suggests 48psi. They will be getting an extra 12psi before the next outing.

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited July 2016 #9

    36psi is a bit low, even for a twin axle.  Do you have a twin axle?

    Ours needs 44psi.

  • Tirril
    Tirril Forum Participant Posts: 439 ✭
    100 Comments
    edited July 2016 #10

    My twin axle states 55 psi  - which is confirmed by the max pressure shown on the walls of the tyres. 

  • Fysherman
    Fysherman Forum Participant Posts: 1,570
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    edited July 2016 #11

    His caravan is a small lightweight single axle.

     

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2016 #12

    My 'new' twin axle Coachman has the tyre pressures on the weight plate ..... 35psi Laughing

  • paul56
    paul56 Forum Participant Posts: 937
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    edited July 2016 #13

    New tyres tomorrow on a 1450kg Bailey and they recommend 45psi

  • Bugs
    Bugs Forum Participant Posts: 480
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    edited July 2016 #14

    For anyone who doesn't have their van's handbook, there is a useful website here:

    http://www.tyresafe.org/check-your-pressures/caravan-pressure-calculator/

    Cheers

    Bugs

  • gygafo
    gygafo Forum Participant Posts: 51
    edited July 2016 #15

    For anyone who doesn't have their van's handbook, there is a useful website here:

    http://www.tyresafe.org/check-your-pressures/caravan-pressure-calculator/

    Cheers

    Bugs

    I can't figure out which option to choose on the tyre size drop down. My tyres must have old style markings, they are 155R13C 8PR 90/88R and my caravan MTPLM is 1000kg. I know the tyres
    are commercial tyres and that the size is 155 x 13 after that I'm lost. I just know that at the caravan manufacturers recommended 36psi the tyres look well underinflated. Can anyone help please?




    Cheers!

    Nigel.

  • xtrailer
    xtrailer Forum Participant Posts: 10
    edited July 2016 #16

    most large single axle vans have 65psi on tyres with a c after the size meaning commercial, most twin axle vans run between 45/50psi with similar rated tyres, remember a large van is weighing one and a half tons on two wheels which is why the pressurers
    are high, you must put that pressure in them they need it and is dangerous at a lower psi.

  • Marksailor
    Marksailor Forum Participant Posts: 57
    edited July 2016 #17

    My Lunar Ariva GT (1998) also is supposed to run at 36 psi, which does seem very low to me; especially as it sits on R12 tyres! Alas the online calculators assume that caravans run on R13 or larger diameter. I have come across this formula on carvan chronicles
    https://caravanchronicles.com/guides/calculate-the-correct-tyre-pressure-for-your-caravan/ which makes some sense... and gives me a much higher pressure for my tyre! Might be worth a comparison with the tyre checker website, but at first glance it looks like
    the same formula!

  • johndailey
    johndailey Forum Participant Posts: 520
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    edited July 2016 #18

    I have a Coachman Amara (2 berth, single axle). Like yourself, I was suspicious of the 65psi quoted but checked with Coachman amongst other enquiries and sure enough it is the correct pressure.

  • MrGarval
    MrGarval Forum Participant Posts: 120
    edited July 2016 #19

    Hi,

    My Bailey single axle is 65 psi and this is not uncommon for caravan tyres, just make sure valve is in good order.

  • gygafo
    gygafo Forum Participant Posts: 51
    edited July 2016 #20

    My Lunar Ariva GT (1998) also is supposed to run at 36 psi, which does seem very low to me; especially as it sits on R12 tyres! Alas the online calculators assume that caravans run on R13 or larger diameter. I have come across this formula on carvan chronicles
    https://caravanchronicles.com/guides/calculate-the-correct-tyre-pressure-for-your-caravan/ which makes some sense... and gives me a much higher pressure for my tyre! Might be worth a comparison with the tyre checker website, but at first glance it looks like
    the same formula!

    Thanks for the  link Marksailor. The calculation came out at 54psi for my Lunar Ariva GTS. I'll inflate them from 36psi tomorrow and and see how the tyres sit in relation to tread contact because at the moment the tyres look very under inflated. We are on
    our second trip out this Thursday and taking the caravan to The Howard at Rosdale Abbey for a few nights and will let you know how it tows when we get back.



    Cheers!

    Nigel.

     

  • Marksailor
    Marksailor Forum Participant Posts: 57
    edited July 2016 #21

    Let us know how you go- have raised our Ariva to 40. Also new tyres next week as current ones use the bonus load for capacity which isnt good- so going for properly sized ones!

  • tigerfish
    tigerfish Forum Participant Posts: 1,362
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    edited July 2016 #22

    Just as a precaution, - in this hot weather read the other thread on this subject under "caravan Tyre pressure - Towing in the heat".  It is in  the tow cars and towing section.

    Mods,  Might it be worth merging two very similar threads?, Although I do accept that the other one is very temperature specific.

    TF

     

     

  • DavidKlyne
    DavidKlyne Club Member Posts: 13,860 ✭✭✭
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    edited July 2016 #23

    TF

    Merging two threads, if only!!!!

    David

  • gygafo
    gygafo Forum Participant Posts: 51
    edited July 2016 #24

    Just as a precaution, - in this hot weather read the other thread on this subject under "caravan Tyre pressure - Towing in the heat".  It is in  the tow cars and towing section.

    Mods,  Might it be worth merging two very similar threads?, Although I do accept that the other one is very temperature specific.

    TF

     

     

    Hi TF, thanks for that but as an ex long distance driver I've inflated to a couple of pounds below recommended pressure due to the recent heatwave. Will probably have to put the rest in tomorrow when we set off to The Howard at Rosedale Abbey. You just watch, I get chance to take a few day's off work and it will rain!



    Cheers!
    Nigel 
  • simonandtessa
    simonandtessa Forum Participant Posts: 18
    edited July 2016 #25

    My twin axle van has a MTPLM of 1530kg and the tryes that are fitted are 175/65R14 86T max psi 50. tyresafe has me at 32psi but I went to check on the caravan chronicles and Ill be honest I got very confused.... can anyone help me?

    Thanks in advance.

  • tigerfish
    tigerfish Forum Participant Posts: 1,362
    1000 Comments
    edited July 2016 #26

    It may be that the tyres fitted now are not to the same spec as the original. What does the handbook say?  Are your tyres the correct ones for the van?

    TF

  • Nuggy
    Nuggy Forum Participant Posts: 512
    edited July 2016 #27

    My twin axle van has a MTPLM of 1530kg and the tryes that are fitted are 175/65R14 86T max psi 50. tyresafe has me at 32psi but I went to check on the caravan chronicles and Ill be honest I got very confused.... can anyone help me?

    Thanks in advance.

    Write your comments here...Using the MTPLM and tyre specification you have given for your tyres, the calculation shown using the Caravan Chronicle website gives a result of 36psi. Using the Tyresafe website there is 'not' an exact match for your tyres.
    You have given the Load Index as 86T and the nearest match they have is 86XL. There will be differences of construction between the two. Using 86XL the Tyresafe calculator gives 32psi for your TA. My choice would be 36psi which would allow for uneven loading
    and still be 14psi below the designed maximum pressure.

  • simonandtessa
    simonandtessa Forum Participant Posts: 18
    edited July 2016 #28

    Thank you for that, much appreciated

  • gygafo
    gygafo Forum Participant Posts: 51
    edited July 2016 #29

    I promised that once we were back from our four nights at The Howard, Rosedale Abbey CC site I would let you know how I went on with correcting my tyre pressures from 36psi to the pressures calculated by using the formula in the link posted by Marksailor.
    The appearance of the tyres once inflated to 54psi was much better but it wasn't until we set off for Rosedale that we noticed the difference. I say we because the wife mentioned it as I was thinking it. "The ride is very smooth" and un-boat-like. It really
    made a difference, what a transformation. The caravan towed, instead of being dragged and to top it of I got an average extra 12mpg.

  • Marksailor
    Marksailor Forum Participant Posts: 57
    edited July 2016 #30

    Thats excellent- glad to hear it. Impressive change in fuel consumption there! We are just back with increased pressures (at 42 psi as calculated) and it certainly did tow better- and the tyres looked better shape as well. We are having new tyres (with higher
    rating, as currently they utilise the bonus load which isn't good. Will then double-check what the new pressures should be.

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