Hi, I have a saved article about this, but I have saved it so well I can't find it! But I remember that you need to gain about 5-6 psi after traveling for an hour or so and your tyres are hot. So get yourself a pressure gauge and do some trial and error. If you increase only 2-3 psi the cold pressure is too high and if you increase 10 psi your cold pressure is is too low.
My van has 265 75 x 16 tyres with a LR of 223 (1.5t) and a max cold of 80 psi, yet another tyre with a lower LR will have a max cold of 50 psi so the pressure to carry the same load will be different....................the same applies to vehicles..............................on a normal temp day just drive for an hour and check your pressure, the old rule of thumb that if your tyre pressure increases by 4-6 psi then all is good if it rises by 8 or more it's too low and lower than 4 it's high, high is actually better than low, for while the high tyre will bounce and have possibly less traction a lower pressure will cause heat which is a tyre killer as well as making the tyre more susceptible to puncture.
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Checking out the places I drove past a thousand times................
Yep keep in mind the tyre heats up and pressures rise . Main thing is to check the pressures ! I've often checked pressures on my cars and often around 20lb ! Nearly half what Tyre plate recommends !! As said light truck tyres pressure maybe different to car style tyres . At recent rego inspection I was told in nsw the tyres will need to light truck tyres on my car trailer so it MAY be the same for vans ? Being similar weight .
Agree with Macka, my rig, car 100series cruiser with boat plus 285L fuel (40psi), van 3.2t (38psi) bitumen, 18-25psi all round off-road, tyres all 265/75/16 LT.
In the last 11yrs fulltime on the road and spend 60/40 off/on road without any major tyre problem.
I have always worked on the following to set starting pressure. This is based on having load sharing suspension, but can also give a good guide for other types.
Your tyres will show a maximum load at a certain pressure printed on the side wall. As an example, ours show each tyre is 1060 kg (maximum load) at 65 psi (maximum pressure).
I know what our van weighs loaded, ie. 2750 kg, so as a guide each tyre supports 690 kg. (2750 kg divided by 4)
Divide 690 by 1060 (the actual load divided by the maximum load), and the answer is 0.65. Multiply the 65 psi (maximum pressure) by that, and the answer is an inflation of 42 psi at full load.
I have used this on our 3 vans and had no tyre issues over 50000 kms.
Do that process on your unit and you will get a good starting pressure to use.
-- Edited by TheHeaths on Thursday 22nd of June 2017 05:51:53 PM
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Regards Ian
Chaos, mayhem, confusion. Good my job here is done
Best to look at the numbers on the side of the tyre
It will tell you what the max load is, and that tyre max pressure
I am led to believe, never put more pressure in than what the tyre says, and ignore the manufacture pressures on the door/plate
If you know that you are less than the maximum weight/load, then you can adjust the pressure down for a less bumpy ride
I have always worked on the following to set starting pressure. This is based on having load sharing suspension, but can also give a good guide for other types.
Your tyres will show a maximum load at a certain pressure printed on the side wall. As an example, ours show each tyre is 1060 kg (maximum load) at 65 psi (maximum pressure).
I know what our van weighs loaded, ie. 2750 kg, so as a guide each tyre supports 690 kg. (2750 kg divided by 4)
Divide 690 by 1060 (the actual load divided by the maximum load), and the answer is 0.65. Multiply the 65 psi (maximum pressure) by that, and the answer is an inflation of 42 psi at full load.
I have used this on our 3 vans and had no tyre issues over 50000 kms.
Do that process on your unit and you will get a good starting pressure to use.
-- Edited by TheHeaths on Thursday 22nd of June 2017 05:51:53 PM
TheHeath hi
I think you have nailed it with your statement. Well said.
I run my tyres to that formula and found with some small adjustment using the old 4lbs rule, I have become very confident with my tyre pressures.
And for driver comfort I run 38 in rears. 33\34ish in front.
Van. For the "Comfort" of the interior. I run 32\34ish.
For all you High pressure advocates, Try a little experiment.
I did several times over the yrs with each new van. Normal Bitumin. Aust rds. NOT freeways.
Hand held radio or phone.
Just get INSIDE of van and travel along in it for a coupla miles. (IF you last that long) NOT counting top line Ind, and Air Suspensions here. Just the NORMAL run of mill vans.
Firstly at 32\34lb. Then raise them to your 40plus
or whatever Used Pressures. Then go for another ride
Less mileage???. Yes. Probably. Slightly. But better grip on road. AND... A MUCH softer ride for everything inside van..
Try it. Just as an experiment.
My cats travel in there. Actually prefer it. On bed. UNDER pillows mainly. Pop out when we stop and open door.
-- Edited by macka17 on Sunday 25th of June 2017 12:19:11 AM
I must be some sort of Neanderthal here hey. I run 29 psi all round in my Patrol tyres (31x10.50x15) unless towing and then rears are upped by 4 psi. So according to these figures in regard to the previous posts ...I should be grossly underinflated then. And the fact that I have recorded just over 100.000 km from my last 3 sets of tyres each means I have shortened tyre life too. Just doesn't seem to add up to me ....but then again maths wasn't my strong point at school either. Hmmm....back to the calculator then..........
Cheers Keith
-- Edited by ST391GQ on Sunday 25th of June 2017 10:28:22 PM
Get it down as low as possible by trial and error.
The tyre dealer suggested 45 -50psi, but I found it far too high and gave my van a very "bouncy" ride, so I kept dropping it down. I'm now on 38psi not getting hot plus gives a bigger footprint on the road and a much softer ride which must help preserve the body and suspension.