Car tyre pressures when towing

MDD10
MDD10 Forum Participant Posts: 335
edited July 2018 in Towcars & Towing #1

So. .what’s the view on this?  Do you inflate tyres to max load pressures before towing,  or work on the basis that the load on the towbar amounts to an average male passnger and no need to inflate to a higher pressure.  Really interested to know views

Comments

  • Tinwheeler
    Tinwheeler Forum Participant Posts: 23,142 ✭✭✭
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    edited July 2018 #2

    Depends what it says in the car's handbook.

  • EasyT
    EasyT Forum Participant Posts: 16,194
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    edited July 2018 #3

    I would say that I increase pressures for towing. However the truth is that  I keep my pressure up for towing and as this is at least 50% of my usage with our tow car I leave them up

  • EasyT
    EasyT Forum Participant Posts: 16,194
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    edited July 2018 #4

    The average well built male passenger tends to sit respectfully in his seat and does not jump up and down on my tow bar hitch. laughing

  • Tigi
    Tigi Forum Participant Posts: 1,038
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    edited July 2018 #5

    My handbook says the rear tyres should be increased to max pressure shown on the "tyre pressure label".

  • ChrisRogers
    ChrisRogers Forum Participant Posts: 435
    edited July 2018 #6

    I do what the car handbook says, solo / light load 32psi all round, full load / towing 35psi front, 44psi rear.

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2018 #7

    I leave them at normal running round pressures. Had no problems one way or t'other.

  • DougS
    DougS Forum Participant Posts: 327
    edited July 2018 #8

    If car is loaded for a holiday then as said, do what the handbook says. There may be an additional increase above fully loaded for towing.

    IMHO you need the extra pressure to stiffen up the sidewalls of the tyres to help improve stability.

    Have always increased to max in handbook when towing and although a little bumpy when travelling solo would rather have that than risk overheating tyres due to low pressure?

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited July 2018 #9

    Driving a car solo with just 1 passenger with tyres inflated to max is a lot more than 'a little bumpy' .....

  • DougS
    DougS Forum Participant Posts: 327
    edited July 2018 #10

    It's a real pain to get tyres up and down when solo/towing.

    We are two people and still have gear in the boot,

    It has worked for us for 7 years and never thought about changing procedure.

  • EasyT
    EasyT Forum Participant Posts: 16,194
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    edited July 2018 #11

    I suppose it depends on the recommended amount of increase. Not much difference in solo/2 front seats occupied operation in our case

  • Unknown
    Unknown Forum Participant
    edited July 2018 #12
    The user and all related content has been Deleted User
  • kentman
    kentman Forum Participant Posts: 147
    edited July 2018 #13

    In nearly 4 decades of towing, I have always raised rear tyre pressures. My current LR Discovery Sport handbook gives two pressures for the rear tyres, one for lightly loaded and one for fully. I use the latter when towing and just put up with the slightly harder ride when driving around solo while we are away

  • dmiller555
    dmiller555 Forum Participant Posts: 717
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    edited July 2018 #14

    I tow with a Volvo XC70 and the recommended economy pressures (38psi) are the same front and back no matter what the load. 

  • richardandros
    richardandros Club Member Posts: 2,681 ✭✭✭
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    edited July 2018 #15

    I am quite particular about this.  The 'normal' tyre pressure on my Touareg is 33psi all round but under heavy load increases to 44psi for the rears - which is a big difference.  I always increase the pressure for towing - and - once on site - reduce them to the 'normal' pressure.  Two reasons - main one is safety - but also I am also conscious of increased tyre wear if the correct pressures aren't adhered to - and at just under £200 a tyre, I'm keen to get as much mileage out of them as possible.

    It only takes about five minutes to get the pressures right - so no great hardship, really.

  • Phishing
    Phishing Forum Participant Posts: 597
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    edited July 2018 #16

    Tyre loadings are calculated at specific pressures for the loading of that tyre. The caravan manufacturers cant be bothered to rate their tyres correctly for each van and just state the max pressure for the tyre.

    The car manufacturers calculate the correct pressures for the loading and (by law) stick a sticker on the drivers door pillar or inside the petrol flap.

    They do this for a reason, the lateral forces on a towing vehicle are far higher than a non towing vehicle. The non towing pressures give the best comfort ride when not towing, the towing pressures give the safest pressures when towing.

    Running at highest pressures stated on the info sticker has little effect on tyre wear, handling or safety but does give a poor ride as it is harsher and more noisy. Riding on lower pressures when towing is dangerous. 

  • harryb
    harryb Forum Participant Posts: 1,536
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    edited July 2018 #17

    Ditto

  • richardandros
    richardandros Club Member Posts: 2,681 ✭✭✭
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    edited July 2018 #18

    "Running at highest pressures stated on the info sticker has little effect on tyre wear, handling or safety"

    I beg to differ - running on over-inflated tyres (for the load) will increase wear in the centre of the tyre and also reduce grip, especially during cornering or braking.

  • Phishing
    Phishing Forum Participant Posts: 597
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    edited July 2018 #19

    I totally agree but running on the manufacturer recommended tyre pressures you are not overinflating the tyres. The tolerances shown on tyre inflation label is recommendation to optimise the handling and comfort but does not give overinflated tyres.

  • LeTouriste
    LeTouriste Forum Participant Posts: 348
    edited July 2018 #20

    With two VW Tourans over 13 years, I always inflate my tyres to maximum pressure when towing.  There are just the two of us, but the car is also loaded with chairs, awning, etc.  Pressures are dropped to normal when on site and car unloaded.  Inflating is not a chore, since I have a Ring heavy duty 12-volt inflator, and is very quiet in use so does not annoy others if used late evening or early morning.

    We are just in the process of changing to a VW Caravelle, so will not know until next week if tyre pressures need to be increased for towing.

    Keeping the tyres at the correct pressures when loaded is important, since an under inflated tyre will suffer more sidewall flexing and thereby increase the amount of heat generated in the tyre.