Nitrogen doesnt expand at the same rate ! Why its used on planes . But its negligible here . The atmo pressure stays much the same . Humidity in the air makes a difference too !!
kgarnett said
02:52 PM Mar 13, 2023
https://en.wikipedia.org/wiki/Aircraft_tire
Aircraft tires are usually inflated with nitrogen to minimize expansion and contraction from extreme changes in ambient temperature and pressure experienced during flight.[6] Dry nitrogen expands at the same rate as other dry atmospheric gases (normal air is about 80% nitrogen), but common compressed air sources may contain moisture, which increases the expansion rate with temperature.[7]
The requirement that an inert gas, such as nitrogen, be used instead of air for inflation of tires on certain transport category airplanes was prompted by at least three cases in which the oxygen in air-filled tires had combined with volatile gases given off by a severely overheated tire and exploded upon reaching autoignition temperature. The use of an inert gas for tire inflation eliminates the possibility of tire explosion.
Warren-Pat_01 said
11:56 PM Mar 15, 2023
My gripe about using nitrogen in tyres is what happens when you have to reduce pressure when travelling on a corrugated road?
Tyre pressures should be discussed with a good tyre dealer about different areas you might drive on & carry something to restore pressure if you had to reduce it.
I had a truckie ask me what pressure I run in my van a couple of days ago at Charters Towers. I told him 55psi cold but suspected they could be a little higher as the pressure increased to +6 psi when hot. He had a similar sized new van, also with one axle & was told to put 40psi in them but he said they always looked flat. I suggested that he loaded his van prior to going for a trip, weigh it on one of our Port Access Road weighbridges & read what was on the tyres & adjust to suite.
Yobarr, I assume your wheels that have those tyres that will support 1550kg are rated accordingly.
One question - what is the maximum load that an alloy wheel van carry? Mine are rated to 1000kg.
Radar said
08:17 AM Mar 16, 2023
My theory for tyre pressures for the car type tow vehicle is read your tyre placard on the drivers door which is pretty well standard these days where you find the information. The car and tyre manufacturers have done all the expensive experimental work of testing their products.
Caravan manufacturers appear to of done none except guote cold maximum pressure off the tyres they hava fitted before delivery of the caravan.
For the caravan I look at it this way, the drive axle on the tow vehicle weighbridge weight of 1740 kgs, the caravan's axle group weighbridge weight is 2420kgs, I run 36 psi cold in the both the drive axle and the caravan tyres and after approximately 2 hours of running on a 32 cel degs day very little change in tyre pressures if any.
I do mostly travel around the 90 kph mark while on back roads but on 4 lanes sometimes little quicker.
When we had our previous 2 tonne single axle caravan we had tried several different tyre pressures. When at 48 psi we would find the bedding on the floor but at 42 psi absolutely nothing moved inside the caravan. The tyre pressures rose to about 44 psi on my test days. So I was very happy with that and at the time of owning that caravan we seem to be needed to travel a lot quicker as we needed to be somewhere for engagements but now just steady as she goes.
It also interesting that the original poster has not been back.
yobarr said
10:21 AM Mar 16, 2023
Radar wrote:
It also interesting that the original poster has not been back.
Hi Ralph. Perhaps the OP feels that he has had his question answered as he dropped in for a look 3 posts back, on 11th March. Cheers
https://en.wikipedia.org/wiki/Aircraft_tire
Aircraft tires are usually inflated with nitrogen to minimize expansion and contraction from extreme changes in ambient temperature and pressure experienced during flight.[6] Dry nitrogen expands at the same rate as other dry atmospheric gases (normal air is about 80% nitrogen), but common compressed air sources may contain moisture, which increases the expansion rate with temperature.[7]
The requirement that an inert gas, such as nitrogen, be used instead of air for inflation of tires on certain transport category airplanes was prompted by at least three cases in which the oxygen in air-filled tires had combined with volatile gases given off by a severely overheated tire and exploded upon reaching autoignition temperature. The use of an inert gas for tire inflation eliminates the possibility of tire explosion.
Tyre pressures should be discussed with a good tyre dealer about different areas you might drive on & carry something to restore pressure if you had to reduce it.
I had a truckie ask me what pressure I run in my van a couple of days ago at Charters Towers. I told him 55psi cold but suspected they could be a little higher as the pressure increased to +6 psi when hot. He had a similar sized new van, also with one axle & was told to put 40psi in them but he said they always looked flat. I suggested that he loaded his van prior to going for a trip, weigh it on one of our Port Access Road weighbridges & read what was on the tyres & adjust to suite.
Yobarr, I assume your wheels that have those tyres that will support 1550kg are rated accordingly.
One question - what is the maximum load that an alloy wheel van carry? Mine are rated to 1000kg.
My theory for tyre pressures for the car type tow vehicle is read your tyre placard on the drivers door which is pretty well standard these days where you find the information. The car and tyre manufacturers have done all the expensive experimental work of testing their products.
Caravan manufacturers appear to of done none except guote cold maximum pressure off the tyres they hava fitted before delivery of the caravan.
For the caravan I look at it this way, the drive axle on the tow vehicle weighbridge weight of 1740 kgs, the caravan's axle group weighbridge weight is 2420kgs, I run 36 psi cold in the both the drive axle and the caravan tyres and after approximately 2 hours of running on a 32 cel degs day very little change in tyre pressures if any.
I do mostly travel around the 90 kph mark while on back roads but on 4 lanes sometimes little quicker.
When we had our previous 2 tonne single axle caravan we had tried several different tyre pressures. When at 48 psi we would find the bedding on the floor but at 42 psi absolutely nothing moved inside the caravan. The tyre pressures rose to about 44 psi on my test days. So I was very happy with that and at the time of owning that caravan we seem to be needed to travel a lot quicker as we needed to be somewhere for engagements but now just steady as she goes.
It also interesting that the original poster has not been back.
Hi Ralph. Perhaps the OP feels that he has had his question answered as he dropped in for a look 3 posts back, on 11th March. Cheers