Highway tire pressures?

[Fizzie]

I dont see that you have too many other options. Shakng a van to retain control in an emergency doesnt seem like a huge compromise to me. A simple swerve on outclassed sidewalls could end badly.

Sorry, wasn't disagreeing with you Will definitely be putting them up to 66psi for next trip but it still seems an incredible amount

As I said before though - where does the 4psi idea come from I don't think anyone has ever complained that their van / CT was too light , & by the many & varied comments here & similar places, most of them are apparently over, or very close to, their legal weight limits, so surely everybody's tyres should be at maximum rated pressure, so why would you want to reduce your pressure or fiddle with it

[Fizzie]

https://www.youtube.com/watch?v=nd-hUX8memY   

Thanks Ed, have seen similar but not that particular example.

Really feel for the poor people passing the semi with everything turning pear-shaped instantly - how would you be if you were having a snooze in the back seat at the time them Boom

[Merts]

Will definitely be putting them up to 66psi for next trip but it still seems an incredible amount

As I said before though - where does the 4psi idea come from I don't think anyone has ever complained that their van / CT was too light , & by the many & varied comments here & similar places, most of them are apparently over, or very close to, their legal weight limits, so surely everybody's tyres should be at maximum rated pressure, so why would you want to reduce your pressure or fiddle with it

The 4psi idea works for tyres which aren't at or very close to their weight limit. Basically, a good starting point is to set the pressure at a percentage of the maximum recommended inflation pressure, based on the percentage of the load rating you are loading them too. For example, if the tyre is rated to 900 kg at 60psi, and your wheel load is 600, you could start at 40psi, and use the 4psi rule to adjust up or down to get the optimum pressure.

In your case, as you are pretty close to maximum load, you need to be pretty close to maximum pressure.

As far as rattling the van to bits, it shouldn't be an issue, as the tyre is designed to be at that pressure for that load. The situation where you might have issues is when the tyre is significantly over-inflated when the load is well below the maximum capacity.

[IanS]

The 4psi idea works for tyres which aren't at or very close to their weight limit. Basically, a good starting point is to set the pressure at a percentage of the maximum recommended inflation pressure, based on the percentage of the load rating you are loading them too. For example, if the tyre is rated to 900 kg at 60psi, and your wheel load is 600, you could start at 40psi, and use the 4psi rule to adjust up or down to get the optimum pressure.

In your case, as you are pretty close to maximum load, you need to be pretty close to maximum pressure.

As far as rattling the van to bits, it shouldn't be an issue, as the tyre is designed to be at that pressure for that load. The situation where you might have issues is when the tyre is significantly over-inflated when the load is well below the maximum capacity.

+1
Don't get too worried about it, as above if your near max load use max inflation pressure, you should also have a manufacturers recommended pressure, what is it?
I would refrain from measuring tyres when they are hot as it doesn't mean a lot, you can get a temp variation from side to side depending on the wind direction and the temperature of the tyre is related to pressure so which side is right?
Fizzie you mentioned earlier about ratings of tyre's, as long as both your axle rating and your tyre rating are greater than your actual load then you are OK, it doesn't matter if you have a 1.6t axle and 1.8t tyres or visa versa, you can carry 1.6t, the lower rated item is always the limiting factor.

[MarkVS]

I run BFG LT A/T on my Pajero, and LT tyres on the camper..I have a CC Exodus 14.

I actually spoke to a technician At BF Goodrich (I am a persistent bugger) and asked him for his advise. He gave me some handy info..
1. This may be obvious, but he said it’s the air in the tyre that carries the load.
2. BFG LT tyres are designed to take 80 psi cold.
3. The less air air you have in a tyre, the more heat it will generate as there is more rubber in contact with the road, and heat is a tyres worst enemy.
4. The idea is to have a tyre maintain its shape on the road, hence the idea is to increase tyre pressure to carry the load and maintain its shape...except for special circumstances like off-road, sand etc. which are then lower speed etc.
5. Car manufacturers recommend tyre pressures that are more to do with the car ( soft ride etc) than the tyre.

So for my setup, on bitumen, over 80km per hour, he suggested 59psi hot on the rears, 50 psi hot on the front. For me, that works out about 50 psi cold on the rear, 44 psi cold on the fronts. He also recommended other pressure for lower speed off-road dirt etc.


It made sense to me.  I am trying it out on my current Kimberley trip and so far so good.

Mark VS

[Fizzie]

What do you run in the Exodus, Mark

[Cristian G]

Great, I’ll try that today.
I did notice our fuel consumption was more than I expected yesterday, but I put that down to our our high all up weight and the roof pod more than anything else.

An update on how it worked out.
I changed the pressures to 36 front, 45 rear and 56 in the camper.
The camper was pretty much spot on with warm tyres and got better as water and food got used along the way.
The car was pretty good. Fronts went up about 6 psi , the rears ended up at 55-56 warm.  I didn’t bother adding more before getting to Perth, but I think I’ll try starting the rears at 48 for our next outing from Perth in a couple of weeks.
Interestingly, when I upped the pressures the camper became much more stable and didn’t roll or wallow around as much (almost none at all) over bumps or when passing trucks. Before that, it was rolling around like it was loaded tail heavy.
Thanks to all for your help, it made our journey much more pleasurable.
Gorto

[MarkVS]

What do you run in the Exodus, Mark

same as the rears in the car