Tyre pressure for AT tyres





Results 1 to 13 of 13
  1. #1
    Join Date
    Aug 2015
    Location
    Gaborone
    Age
    37
    Posts
    100
    Thanked: 44

    Default Tyre pressure for AT tyres

    Hi guys. I recently bought a set of Goodyear Wrangler AT tyres for my 2001 RAV4 AWD - size 215/70R16.

    The guys at the tyre shop pumped them up to an "ideal" 2.2 bar. When I asked them what would be the lowest I could deflate them to for off-road driving, they said I shouldn't go less than 1.8 bar.

    My first question is whether that is really the lowest I can/should go when deflating and will that (small) difference have any effect at all on my grip in sand, on gravel etc.? I've heard that guys driving proper 4x4's with larger tyres go down to about 1 or even 0.8 (any less and the tyre may actually come off the rim), but can I not go that low with my tyres as well and what would indeed be the lowest I could/should go when tackling sand, gravel etc.?

    My second question is when should the tyre pressures differ between the front and back tyres? i.e. if I'm full-laden at the back, should the back tyre pressure be considerably higher than the front (and if so, why?) or should they more or less be kept the same?

    Any info on the matter would be appreciated, thanks. Jovan

    1999 Toyota Prado TZ, 3.4L, V6, petrol, auto

  2. The Following User Says Thank You to Jovan Djokic For This Useful Post:


  3. #2
    Join Date
    Jul 2012
    Location
    swakopmund
    Age
    47
    Posts
    4,573
    Thanked: 1310

    Default Re: Tyre pressure for AT tyres

    They are clueless regarding tyres , shocking advice to give a client. a "70" profile can safely be deflated to 0.8 in soft sand , if he means gravel road the 1.8 would be ok, but very strange behaviour

  4. The Following User Says Thank You to Bartho For This Useful Post:


  5. #3
    Join Date
    Oct 2009
    Location
    Stellenbosch
    Age
    69
    Posts
    3,953
    Thanked: 498

    Default Re: Tyre pressure for AT tyres

    With your 70 profile AT tyre you could easily go down to 1.2(F) and 1.4(R) for rough gravel. It makes a world of difference if, as an example, you are driving in Kgalagadi on some badly corrugated sections. Just keep your speed below 80 at all times, preferably below 70.

    For relaxed sand driving even 0.7 is OK, but...
    Don't make any sharp turns or the tyres will debead.
    Eggie.

    What this country needs more and more, are more unemployed politicians.
    - apology to Edward Langley.

  6. The Following User Says Thank You to Eggie For This Useful Post:


  7. #4
    Join Date
    Oct 2010
    Location
    Bloemfontein
    Age
    62
    Posts
    2,254
    Thanked: 371

    Default Re: Tyre pressure for AT tyres

    I am a Good Year Wrangler man for many moons. My tyre pressure for gravel is normally between 1.6 and 1.8, depending on the road. Driven a few thousand kilos on Nam gravel, and the well known Kgalagadi hoppers, even went as low as 1.2.
    Pajero GLS Exceed 2014 LWB &
    Jeep Cherokee 2001 2.5 Diesel, Gone to Jeep Heaven
    Toyota Hilux, plaas bakkie
    Platkar Swambo's MB

  8. The Following User Says Thank You to stevan For This Useful Post:


  9. #5
    Join Date
    May 2014
    Location
    Cape Town
    Age
    40
    Posts
    323
    Thanked: 34

    Default Re: Tyre pressure for AT tyres

    Have wranglers on my suzuki. Normal road pressure is 1.8. Dunes is 0.5-0.8. They are 245/70/16.
    2009 Toyota Fortuner Epic V6

  10. The Following User Says Thank You to faanie For This Useful Post:


  11. #6
    Join Date
    Aug 2015
    Location
    Gaborone
    Age
    37
    Posts
    100
    Thanked: 44

    Default Re: Tyre pressure for AT tyres

    Thanks guys for the input! It did seem strange when the tyre-shop guy said "no lower than 1.8", but that's why this forum exists, to provide the answers that the "professionals" cant!

    Can't wait to test my Wranglers out on some sand and "horrible" gravel roads! A trip to Tuli Block in Botswana in September is already on the cards which will be a good starting point. Then SWAMBO and I are planning a 12-day roadtrip from Gaborone up to Kasane via Tuli-Gweta-Maun in December, and then the tyres will really show what they are made of!

    Thanks again for all the input!

    Cheers,
    Jovan

    1999 Toyota Prado TZ, 3.4L, V6, petrol, auto

  12. #7
    Join Date
    Mar 2011
    Location
    Walker Bay
    Age
    76
    Posts
    9,068
    Thanked: 1021

    Default Re: Tyre pressure for AT tyres

    I drive with 1,3 in Kgalagadi with the Suzuki and would be quite happy to go down to 1.1

    Even when they deliver a new car you find the tyres pumped to 2.6. Crazy!

    ďAfrica changes you forever, like nowhere on earth. Once you have been there, you will never be the same." - Ernest Hemingway

  13. #8
    Join Date
    Aug 2010
    Location
    Pretoria
    Age
    56
    Posts
    429
    Thanked: 47

    Default Re: Tyre pressure for AT tyres

    Quote Originally Posted by Paul Dold View Post
    I drive with 1,3 in Kgalagadi with the Suzuki and would be quite happy to go down to 1.1

    Even when they deliver a new car you find the tyres pumped to 2.6. Crazy!
    On tar road AT Tyres are correct at about 2.4-2.5 it gives the correct road contact surface and allows correct sidewall support for speed.

    On on dirt roads smooth 1.8 is good.

    Corrugated 1.4-1.6 allows for directional control, during oscillation of the suspension

    soft sand and beach 0.8-1.2 will allow for floatation on the surface and provide an elongated tread surface contact area much like a small tank track.

    It is always not advisable to drive on a hard surface at too low a pressure at speed, the heat build up will damage the tyre.

  14. The Following User Says Thank You to hedjudd For This Useful Post:


  15. #9
    Join Date
    Jun 2014
    Location
    Cape Town or Jansenville or missing...
    Age
    39
    Posts
    10,505
    Thanked: 3060

    Default Re: Tyre pressure for AT tyres

    We owned a RAV for 340 000km on mostly bad gravel, 1.8 seemed a good all round pressure. Brilliant vehicle.

    I'd say drop to 1.2 for trails, 0.8 for sand, no worries.

  16. #10
    Join Date
    Nov 2010
    Location
    Jeffreys Bay
    Age
    79
    Posts
    167
    Thanked: 3

    Default Re: Tyre pressure for AT tyres

    Greetings,
    Interesting chat on the AT tyres. I used to drive a Ford Ranger 4x4 with Goodyear AT Tyres. I now have built my own camper into a Hyundai H1 Panel Van and fitted Goodyear AT tyres. I no longer have 4x4, but the Hyundai is rear driven. We love to go to Kgalagadi and Namibia and have done a lot of gravel driving there. I intend to lower pressure to 1.6 in Kgalagadi and Namibian gravel. If I come across some sandy drifts on Namibian gravel routes should I lower the pressure even more to get through? Or will I be okay with 1.6? Should the drive wheels (rear) have a lower pressure in sand than the front free wheeling wheels? Thanks for any info on this.

  17. #11
    Join Date
    Oct 2009
    Location
    Stellenbosch
    Age
    69
    Posts
    3,953
    Thanked: 498

    Default Re: Tyre pressure for AT tyres

    Quote Originally Posted by Punda View Post
    Greetings,
    Interesting chat on the AT tyres. I used to drive a Ford Ranger 4x4 with Goodyear AT Tyres. I now have built my own camper into a Hyundai H1 Panel Van and fitted Goodyear AT tyres. I no longer have 4x4, but the Hyundai is rear driven. We love to go to Kgalagadi and Namibia and have done a lot of gravel driving there. I intend to lower pressure to 1.6 in Kgalagadi and Namibian gravel. If I come across some sandy drifts on Namibian gravel routes should I lower the pressure even more to get through? Or will I be okay with 1.6? Should the drive wheels (rear) have a lower pressure in sand than the front free wheeling wheels? Thanks for any info on this.
    It does not sound as if you will need to go lower than your suggested 1.6.
    Should you hit a "really" bad road, drop to 1.4 for more comfortable driving.

    If you get stuck in sand, just don't dig in - stop. Lower tyres to 0.8 all round to get out and get through. It is amazing what one can get away with, even with 2x4. Do pressure up before driving off again.

    What is the profile no of the tyres?
    Eggie.

    What this country needs more and more, are more unemployed politicians.
    - apology to Edward Langley.

  18. #12
    Join Date
    Nov 2010
    Location
    Jeffreys Bay
    Age
    79
    Posts
    167
    Thanked: 3

    Default Re: Tyre pressure for AT tyres

    Thanks Eggie, my tyres are 215/70/16.

  19. #13
    Join Date
    Oct 2009
    Location
    Stellenbosch
    Age
    69
    Posts
    3,953
    Thanked: 498

    Default Re: Tyre pressure for AT tyres

    Quote Originally Posted by Punda View Post
    Thanks Eggie, my tyres are 215/70/16.

    Good. A 70 profile leaves quite a bit for gravel & sand.
    They will serve you well for what you intend to do.
    Eggie.

    What this country needs more and more, are more unemployed politicians.
    - apology to Edward Langley.

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


Tags for this Thread

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
  •