How do I use tyre pressure to get better handling on different surfaces?





Page 1 of 2 1 2 LastLast
Results 1 to 20 of 27
  1. #1
    Join Date
    Jun 2014
    Location
    Cape Town Southern Suburbs
    Posts
    3,036
    Thanked: 1098

    Default How do I use tyre pressure to get better handling on different surfaces?

    I have a Honda CRV, softroader with basic AWD, I'm using the stock 15" rims and stock tyres are 205/70/15, on tar I ran 2.5bar.
    What kind of pressure ranges could be useful on surfaces like poor gravel roads with heavy corrugations, beach sand, mud and other surfaces I may encounter?
    How should I adjust my driving when dropping the pressure really low, I have seen people mention pulling tyres off the bead can happen if you aren't careful?

    Any other general advice in this regard is welcome.

    Edited it to be less specific.
    Last edited by Skylark; 2018/07/22 at 09:43 PM.

  2. #2
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,506
    Thanked: 3060

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    First tell us how long is a piece of string

  3. #3
    Join Date
    Jun 2014
    Location
    Cape Town Southern Suburbs
    Posts
    3,036
    Thanked: 1098

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by JohanSlabbert View Post
    First tell us how long is a piece of string
    I'm not expecting to get specific tyre pressures, just a general idea on what kind of pressure ranges to use on different surfaces, some tips from those that have experienced these conditions and which I can test when the scenarios arises.

    For instance driving on soft beach sand from what I have read 0.8 - 1.2bar could suffice?
    Last edited by Skylark; 2018/07/22 at 09:43 PM.

  4. #4
    Join Date
    Oct 2016
    Location
    Pretoria
    Posts
    203
    Thanked: 202

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Isuzu bakkie - 255/60 R18

    Tar towing : back 2.8 front 2.2

    Tar solo - not loaded : 2.0 front and back

    Gravel : 1.2 to 1.5 all round - lower if the roads are rough - possibility of side wall damage

    Sand : 1.0 to 1.2 all round

  5. #5
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,506
    Thanked: 3060

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by Skylark View Post
    I'm not expecting to get specific tyre pressures, just a general idea on what kind of pressure ranges to use on different surfaces, some tips from those that have experienced these conditions and that I can test when the scenario arises.

    For instance driving on soft beach sand from what I have read 0.8 - 1.2bar could suffice?
    Trial and error is your best teacher here, there are just so many variables that it's hard to give solid advice.

    Quote Originally Posted by Skylark View Post
    I have a Honda CRV, softroader with basic AWD, I'm using the stock 15" rims and stock tyres are 205/70/15, on tar I ran 2.5bar.
    What would be suitable pressures for decent gravel roads, poor gravel roads with heavy corrugations, beach sand, mud and other surfaces I may encounter?
    How should I adjust my driving when dropping the pressure really low, I have seen people mention pulling tyres off the bead can happen if you aren't careful?

    Any other general advice in this regard is welcome.
    But I'll give it my best shot anyway.

    Assuming a light load and sticking to under 100km/h:

    Decent gravel: 1.8 bar

    Poor gravel: 1.5 but don't go above 80 for too long.

    Then:

    Sand: start 1 bar but you could drop to as low as 0.6.

    Mud: Some will say a hard tyre cuts through the mud better to the firm stuff underneath. I tend to drop the pressures in mud to around 0.8 bar. You'll have to see what works best for you and the vehicle.

    As for a tyre coming off the rim, unless you drive like a hooligan, above 0.8 bar there's not much chance of it happening. But good advice is to avoid sharp turns at any speed over walking pace. Better advice is learn how to put a tyre back on the bead with a good (fast) compressor.

    Like I said, many variables, for instance, an empty vehicle on a cold day could cruise for hours at 100 with the tyres at only 1.5 bar, but the same vehicle on the same road, same speed, same 1.5 bar, but fully loaded on a 45 degree summers day, is a recipe for tyre failure.

    Go play and learn, is the best way.
    Last edited by Johan Slabbert; 2018/07/22 at 10:34 PM.

  6. #6
    Join Date
    Aug 2013
    Location
    Helderkruin
    Age
    54
    Posts
    1,912
    Thanked: 399

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Slegte grondpad 1.5 bar
    Sand so 1 bar
    Modder bly my bande hard.
    Beste is maar om jou voertuig te gaan toets en kyk op watse banddruk doen hy die beste en as jy bietjie gelaai is ook.

  7. The Following User Says Thank You to Leon Venter For This Useful Post:


  8. #7
    Join Date
    Oct 2009
    Location
    Cape Town
    Age
    46
    Posts
    2,741
    Thanked: 185

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Really good advise from Johan.

    Beware mud. It turns any HT or AT tyre into racing slicks and than you are stuck. I found out that the in the Riversdal mountains when I started off-roading. Mud just clogged up a brand new set of BFG ATs and I were left with no traction/grip. I upgraded to mud tyres as soon as I could afford them.

    Blowing down is not only about floatation and a bigger footprint. It is also about comfort.
    Last time I did Gamkaberg, the campers next to me watched me blown down my tyres to 1.5bar. Their comment was that they do not need to blow down the tyres on their new Hilux DC, because it is a rocky trail.
    They left 30 mins before me and halfway up the mountain, I caught up with them. The 5 passengers looked like skittles inside the toyota bouncing of each other and the cab. We had a smoother ride (and faster (in 2nd gear low range)), but swambo was still complaining about the jarring. At the top campite, I blew down to 1 bar. Happy, smooth sailing from then on.
    We spent about 45mins at the top campsite before continuing on the trial. The hilux never got there... (And not because the toyota couldnt do a fairly easy trail, but I'm sure his bruised wife said to turn around)

    PS I never go over 80kph when my tyres are at 1.5bar or lower. Even on a national road after coming of a trail. Yes, I'm lazy and would rather pump at the next town.
    PSS Get yourself a little digital tyre pressure gauge. It is scary how inaccurate petrol station gauges can be.
    Last edited by RogueFrontier; 2018/07/22 at 10:35 PM.
    -----------------------------
    Isuzu Frontier 280LX 4x4 2001

  9. The Following 3 Users Say Thank You to RogueFrontier For This Useful Post:


  10. #8
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,506
    Thanked: 3060

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by RogueFrontier View Post
    . The 5 passengers looked like skittles inside the toyota bouncing of each other and the cab. .
    Don't you know that's normal in a Hilux

    Oh, and spraying Kahlua over a keyboard makes for a very difficult cleanup...


  11. #9
    Join Date
    Oct 2009
    Location
    Cape Town
    Age
    46
    Posts
    2,741
    Thanked: 185

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by Leon Venter View Post
    Modder bly my bande hard.
    Hoekom?
    -----------------------------
    Isuzu Frontier 280LX 4x4 2001

  12. #10
    Join Date
    Oct 2009
    Location
    Cape Town
    Age
    46
    Posts
    2,741
    Thanked: 185

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by JohanSlabbert View Post
    Don't you know that's normal in a Hilux

    Oh, and spraying Kahlua over a keyboard makes for a very difficult cleanup...

    Hey - jy moenie by die werk drink nie!
    -----------------------------
    Isuzu Frontier 280LX 4x4 2001

  13. #11
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,506
    Thanked: 3060

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by RogueFrontier View Post
    Hey - jy moenie by die werk drink nie!
    Ek doen quality control

    Af gewees vandag

    I think the hard tyre in mud comes from the idea that a harder tyre will cut through the "slush" and find grip on the firm stuff underneath. Whereas a soft tyre will "float" on top and have no grip.

    But I'm in Cape Town and we haven't seen mud in a long time.

  14. #12
    Join Date
    Aug 2013
    Location
    Helderkruin
    Age
    54
    Posts
    1,912
    Thanked: 399

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by RogueFrontier View Post
    Hoekom?
    Dit is hoe ek nog altyd ry in modder en ry nogal heelwat modder nou op die oomblik ook.

  15. #13
    Join Date
    Oct 2009
    Location
    Cape Town
    Age
    46
    Posts
    2,741
    Thanked: 185

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by JohanSlabbert View Post
    Ek doen quality control

    Af gewees vandag

    I think the hard tyre in mud comes from the idea that a harder tyre will cut through the "slush" and find grip on the firm stuff underneath. Whereas a soft tyre will "float" on top and have no grip.

    But I'm in Cape Town and we haven't seen mud in a long time.
    A restaurant owner that gets time off is a rarity!

    I acknowledge there are hundreds of kinds of muds and I'm not a mud expert, I just have a healthy respect for it, but:

    I would want floatation, because when you start dragging diffs and chassis into mud, you have lost the fight. Just like sand.
    I want as big a footprint as possible to make every knobbly work for me. The cape mud is also more like a hard surface covered in an oil slick, than just a mushy swamp.
    And what I remember when I did product research into mud tyres, magazines doing mud tyre shootouts, the lower they went on tyre pressures, to further all the tyres went on the test track. That was common to all the articles.
    And comfort.

    Because I know I do not know everything, I would like to know the reasoning (and experience) behind other peoples' beliefs.
    Last edited by RogueFrontier; 2018/07/22 at 11:09 PM.
    -----------------------------
    Isuzu Frontier 280LX 4x4 2001

  16. #14
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,506
    Thanked: 3060

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by RogueFrontier View Post
    A restaurant owner that gets time off is a rarity!

    I acknowledge there are hundreds of kinds of muds and I'm not a mud expert, I just have a healthy respect for it, but:

    I would want floatation, because when you start dragging diffs and chassis into mud, you have lost the fight. Just like sand.
    I want as big a footprint as possible to make every knobbly work for me. The cape mud is also more like a hard surface covered in an oil slick, than just a mushy swamp.
    And what I remember when I did product research into mud tyres, magazines doing mud tyre shootouts, the lower they went on tyre pressures, to further all the tyres went on the test track. That was common to all the articles.
    And comfort.

    Because I know I do not know everything, I would like to know the reasoning (and experience) behind other peoples' beliefs.
    I can tell you this, on the Karoo farm roads that turns into clay when it rains, an old farm Hilux on hard (2.5bar) skinny tyres is a lot more stable at speed than with soft tyres. Sometimes the momentum carries you through patches where you'll get stuck if you stopped.
    But that's not strictly off-roading, more like muddy on-roading.

  17. #15
    Join Date
    Oct 2009
    Location
    Cape Town
    Age
    46
    Posts
    2,741
    Thanked: 185

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    So far my strategy has worked for me. The KL71 at 1 bar have always stuck like velcro for me.

    In the cape it is also difficult to get away from any trail that doesnt involve mountains. You will be stopping often.

    Only once have I needed to attempt a pull away a 2nd time and that was doing switch backs up the side of a mountain on a trail rated 3 in the dry. I went and did it in pouring rain.

    PS I'll be seriously impressed with your farm mud if you couldnt pull away the jeep in it.
    -----------------------------
    Isuzu Frontier 280LX 4x4 2001

  18. #16
    Join Date
    Jun 2014
    Location
    Cape Town Southern Suburbs
    Posts
    3,036
    Thanked: 1098

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Thanks for the great tips and advice guys, just what I needed.

    Are there things to be careful of when negotiating beach or river sand?

    I'm assuming keeping you speed up helps, should you always plan to stop in a location that's easy to drive off from, perhaps with a slight downhill?
    Last edited by Skylark; 2018/07/23 at 12:41 AM.

  19. #17
    Join Date
    May 2010
    Location
    Port Elizabeth
    Age
    35
    Posts
    1,226
    Thanked: 217

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Quote Originally Posted by Skylark View Post
    I'm assuming keeping you speed up helps, should you always plan to stop in a location that's easy to drive off from, perhaps with a slight downhill?
    Yes downhill or flat is better than uphill. Also just try stopping as smoothly as possible - try to keep the sand piling up in front of your wheels as little as possible - if you dont need to dont use your brakes when stopping just coast to a stop.

  20. The Following User Says Thank You to JurgenSteyn For This Useful Post:


  21. #18
    Join Date
    Sep 2015
    Location
    Cape Town
    Posts
    781
    Thanked: 119

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    Although not asked, on tar one can try over inflated the rear tyres slightly if you normally experience a lot of under-steer. All four of my tyres break traction at the same time now when pushed hard into a corner.

    When going down any terrain with less grip, use engine braking in gear and just jab the brakes as required.

    In the Kgalagadi, you often travel in soft, corrugated river sand (first pic), which is why you see this sign (second pic) at the filling station.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Kg_Soft_Sand.JPG 
Views:	135 
Size:	72.9 KB 
ID:	495982   Click image for larger version. 

Name:	Kg_Tyre_Pressure.JPG 
Views:	158 
Size:	38.2 KB 
ID:	495983  
    Renault Duster 4WD Gen1: No Meow

  22. #19
    Join Date
    Jul 2011
    Location
    Durban
    Age
    55
    Posts
    4,941
    Thanked: 829

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    All my perceptions (and experience) regarding tyres and tyre pressures went out the window after a week of game drives in Botswana - 7.5 x 16 pumped to 3.5bar!!
    FJC - Just Cruising

  23. #20
    Join Date
    Mar 2007
    Location
    Windhoek
    Age
    58
    Posts
    1,734
    Thanked: 719

    Default Re: How do I use tyre pressure to get better handling on different surfaces?

    For general off-road driving I deflate to 20% below normal tar road pressure and for sand to 50% below normal tar road pressure

    Johan 😎
    2011 Daihatsu Terios 4x4
    2018 Isuzu KB300 Double Cab 4x4 Auto

Page 1 of 2 1 2 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •