Weight and tyre pressures - a shock! (1 Viewer)

[Wh05apk]

For the first time, yesterday I had a chance to weigh my van, more or less in trip ready mode, full water, diesel, gas, bikes, just a little light on food and drinks, however I got a shock, our max weight is 5.0t and we came in at 4.920t, so only 80kg to play with!

Normally we pickup/drop off my mum and her luggage at my sisters, so with her onboard we will be over weight, I naively thought we would be about 4.5t as unladen is quoted as 4.0t, obviously all the toys on board have made a massive difference.

As a result of this I have dropped this tyre pressures from 70psi on the front and 60psi on the rears (tag) to 59psi and 47psi (a couple of pound extra over what tyresafe recommend) and what a difference, it is still no bentley, but it smoothes the road imperfections instead of crashing over them, a much nicer rider and so much quieter - presumably less damaging due to vibration/jolting to the van itself, why do manufacturers always recommend rock hard presssures?

 

[stevewagner]

What about the individual axle weights?

 

[Guigsy]

why do manufacturers always recommend rock hard presssures?

Because there's more safety headroom when people don't check them between services. And on a billiard table smooth test track, it gives a more flattering mpg.

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[Wh05apk]

What about the individual axle weights?

1960 front max 2100

Rear 2960 max 1600 each (tag so 3200 total)
Aircon, towbar 246ah gel battery, 420w solar, e bikes, ramps, 2x11kg gas, barbecue, sat dish, TV, tools, probably more.

 

[Spriddler]

And on a billiard table smooth test track, it gives a more flattering mpg.

That's exactly so. I have a pal who is a development and test engineer with a world leading automotive engineering consultancy and I was staggered at some of the lengths to which vehicle manufacturers go to produce good figures for their vehicles.

 

[Mike123]

Assume with MoHo tyres, pressure are related to the fact they are in essence commercial tyres and are designed to deal with the weight and different conditions, etc

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[Augusta08]

???? I don't understand you're heavier than you expected so you... dropped the tyre pressure??? You need to speak to an automotive engineer.

 

[Wh05apk]

???? I don't understand you're heavier than you expected so you... dropped the tyre pressure??? You need to speak to an automotive engineer.

As I didn't have an accurate figure for axle weights I could only go with the rock hard pressures recommended by the manufacturer, now I know the actual weights I can set the pressures correct for those weights.