new tyres today concern about preasure

Submitted: Thursday, Jun 22, 2006 at 17:59
ThreadID: 35183 Views:1817 Replies:9 FollowUps:7
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hi all bought some new tyers for the landcruiser today and the young lad didnt seem to have much idea about tyer preasure as he was new to the game, ok all please can you tell me whats the correct tyer preasure,i have fitted today lt265/75r16 e to my cruiser can some one tell me the corrcet preasure 75% town driving empty and the rest dirt and gravel and beach the tyers are AT the lad put 34psi all round and said that will do what do you all think, by the way have a kamar wheel on the back and also gas tank at the rear and alloy bull bar at front no winch yet. regards stan
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Reply By: Member - DOZER- Thursday, Jun 22, 2006 at 18:40

Thursday, Jun 22, 2006 at 18:40
Stan
40 psi is about right....all round. Lower it on gravel to what you have in them now...
Andrew
b4 you bag me out, walk a mile in my shoes, then your a mile away and have my shoes :)

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Classifieds: Landcruiser 200 series /100 series 4 alloy rims with tyres and nuts GC

AnswerID: 179926

Reply By: Exploder - Thursday, Jun 22, 2006 at 18:52

Thursday, Jun 22, 2006 at 18:52
34-36 is what just about every tyre shop puts in most tyres from my experience.

What is the MAX Cold inflation temp printed on the side of the tyre, I manly run my tyres within 10PSI of that on road. Eg. Mine is 50PSI Max inflation when cold, I run my tyres at 40-44PSI on-Road, and sometimes off too if I am feeling lazy LOL.

When I adjust pressure I run somewhere around these
Gravel roads 38-36
Tracks 36-28
Beach/ sand 24-15

This is what has worked for me, Others may be different .
AnswerID: 179932

Follow Up By: D-Jack - Thursday, Jun 22, 2006 at 18:59

Thursday, Jun 22, 2006 at 18:59
Going by that theory I should be running my 10 ply Cooper ATRs at 70PSI!
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FollowupID: 436116

Follow Up By: Exploder - Thursday, Jun 22, 2006 at 19:14

Thursday, Jun 22, 2006 at 19:14
Like I said>
This is what has worked for me with my tyres, 6Ply LT Cooper AT's

Personally I would probably of tryed running the 10Ply tyres at 60 or something but I don’t know, as I have never had a set 10 Ply tyres before, but you obviously didn’t by 10Ply tyres for a smooth crisp ride?
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FollowupID: 436117

Follow Up By: Member - Oldplodder (QLD) - Thursday, Jun 22, 2006 at 20:09

Thursday, Jun 22, 2006 at 20:09
Same here, my 10 plies, max 80 psi, should run them at 70 psi by that suggestion.

I find they start wearing in the middle at any more than 40 psi, so stick to about 38psi for normal use on bitumen, empty that is.

Nope , not necessarily a soft ride, but hey it's a 4wd.
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FollowupID: 436127

Follow Up By: Exploder - Thursday, Jun 22, 2006 at 20:28

Thursday, Jun 22, 2006 at 20:28
So in what circumstances would you run them at 70PSI?? Why rate the tyre at that pressure if it can’t be used at that pressure.

If they can go to 80PSI at 40PSI they are only 50% inflated which makes it sound as if they are under inflated, But as you say they are over inflated at 40PSI as they are wearing in the middle!!??

Or am I looking at this all wrong?
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FollowupID: 436133

Follow Up By: Muddy doe (SA) - Thursday, Jun 22, 2006 at 23:02

Thursday, Jun 22, 2006 at 23:02
Like D-Jack I have the 10 ply Cooper ATR on my Prado.

I run 40 psi all round on bitumen, 28-30 psi on good gravel, 25 psi on crappy gravel or gibbers, 18 to 20 psi on sand.

Works good for me.

Anthing over 45 psi is just too rough a ride (even in a 120 Prado which ride great) and would risk wearing out the centre of my tread.

Muddy

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FollowupID: 436162

Follow Up By: Member - Oldplodder (QLD) - Friday, Jun 23, 2006 at 20:09

Friday, Jun 23, 2006 at 20:09
The 10 plys (well, we all know that they are actually 4 plt, 2 nylon, 2 steel) but they are 116 load rating, so at 80 psi, they are rated to carry 1050kg each, or 2100kg per axle. Now the pajero weighs 1870kg, and 2580kg gross fully loaded. Rough guess is that the rear axle with car empty is about 850kg, and about 1400 kg loaded. So empty I am under 50% of capacity of the tyres, so 36 to 40 psi is about right, and when fully loaded I run about 50/55 psi, which is about the right ratio (50/80) of 2580 kg.
Now 6 ply tyres are about 102 load rating from memory (650kg each) , and max pressure of 50 psi? So running 32/36 empty and 40/45 full, which is roughly the right ratio.
So to run 80 psi, I would need to really overload the car! So are they a waste of time? Some would say so.

But the advantage of 10 ply tyres is less stakes through the treads and side walls from the thicker and heavier construction (mainly rubber in the side walls). Yes, it is a lot stiffer ride, but I will put up with it.
Notice on this forum that some people are running 18 ply cross plies for serious cross country work, for the staking reason. I don't need that and prefer the radial construction for road use.
It is all a compromise is'nt it :-)))
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FollowupID: 436357

Reply By: luch - Thursday, Jun 22, 2006 at 19:09

Thursday, Jun 22, 2006 at 19:09
It's trial and error you need to monitor tyre wear (around the edges) , how it handles on road surfaces both sealed and un sealed, loaded or empty and comfort

start by running what you tyre placard indicates then work from that

I personaly run 35psi empty and up to 46psi loaded

i also have a kaymar rear step towbar & wheel
steel bar on the front with a winch

by using the info above you will soon work out your ideal pressure
AnswerID: 179934

Reply By: Member - Vincent A M (NSW) - Thursday, Jun 22, 2006 at 19:14

Thursday, Jun 22, 2006 at 19:14
Its trial & error
But on the Dirt/gravel/gibbers remember all the old timers & tire repairs all say never over 35psi & if possible closer to 30
AnswerID: 179935

Follow Up By: Member - AVA 191 (QLD) - Thursday, Jun 22, 2006 at 19:30

Thursday, Jun 22, 2006 at 19:30
All except me that is hehe......

fwiw, I used close to what exploder said, on my 80 series with that size tyre. We got 93,000 outta the set - only one flat by virtue of a 3" nail.
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FollowupID: 436120

Reply By: Member - Bware (Tweed Valley) - Thursday, Jun 22, 2006 at 19:23

Thursday, Jun 22, 2006 at 19:23
I don't have an answer for you mate; just more questions. You are asking for correct pressures, but correct for what? Even tyre wear? Load bearing? Comfortable ride? These could be 3 different answers. Tyre brand can influence as well. As others have said; it's trial and error.
AnswerID: 179939

Reply By: Mikee5 (QLD) - Thursday, Jun 22, 2006 at 19:35

Thursday, Jun 22, 2006 at 19:35
If they are LT or light truck tyres - the Cooper guy said 50 plus on a landcruiser. That is what I run on bitumen. lower - trial and error for gravel, lower again for sand. Keep checking for wear either on the centre of the tread - too hard, edges go first - too soft.
AnswerID: 179940

Reply By: ev700 - Thursday, Jun 22, 2006 at 22:55

Thursday, Jun 22, 2006 at 22:55
The dealer said 38 psi for my LC100 on the GrandTreks , but to drop as far as 36psi if we considered ride was too rough. I asume that would work out at 40psi with a load.

AnswerID: 179982

Reply By: Alloy c/t - Friday, Jun 23, 2006 at 09:29

Friday, Jun 23, 2006 at 09:29
Might sound silly to some , but if you realy want your tires to last on the black stuff start your cold pressure at what your tire placard recommends for load/speed then when tires are hot [60/100klm] drive check pressure again ,if 4psi increase pressure is correct , if higher increase cold starting pressure was to low ,,if lower than 4psi increase from cold starting pressure was to high ,, only for the black stuff ,,let the bun fight begin. LOL
AnswerID: 180032

Reply By: stans truck - Friday, Jun 23, 2006 at 11:52

Friday, Jun 23, 2006 at 11:52
ok thanks guys will run at 36psi empty around town and see how we go thanks forall your input regards stan
AnswerID: 180051

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