Tyre pressure , know one knows !

[Howard H]

This tyre pressure thing is I am sure a complete mystery to most of us , I recently had two Toyo tyres fitted now the Michelin I had on before ran at 5 bar now I have the toyos the recommended pressure by a well respected member on here was 65 psi the tyre man who fitted The tyres said a min of 70 psi now Toyo tyres have emailed with 42 psi for the front which seems really low but they should know I guess . Why is it so difficult ?

 

[Jim]

No matter what the circumstances Michelin always seem to advise 80psi

 

[Otter Spotter]

This tyre pressure thing is I am sure a complete mystery to most of us , I recently had two Toyo tyres fitted now the Michelin I had on before ran at 5 bar now I have the toyos the recommended pressure by a well respected member on here was 65 psi the tyre man who fitted The tyres said a min of 70 psi now Toyo tyres have emailed with 42 psi for the front which seems really low but they should know I guess . Why is it so difficult ?

Did you give Toyo your axle weights ? The front will be different to the rear. Take your van to a weighbridge to get the weights checked with normal fuel and equipment onboard.
no one can really be accurate without the axle weights

 

[Howard H]

Did you give Toyo your axle weights ? The front will be different to the rear. Take your van to a weighbridge to get the weights checked with normal fuel and equipment onboard.
no one can really be accurate without the axle weights

I gave them the weights they came back with 42 psi on the front 59 psi on the rear

 

[mikebeaches]

No matter what the circumstances Michelin always seem to advise 80psi

I've always found their recommendation is always 80 psi on the rear axle, but they will provide a weight-related pressure for the front axle.

It always frustrated me because I've had vans with relatively lightweight load on the back axle, and most standard Ducato chassis already give a harsh ride at the rear.

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[Hettie's Crew]

I gave them the weights they came back with 42 psi on the front 59 psi on the rear

Similar pressures to what Continental recommends for ours.
I don’t think Toyo do a chart but check this Continental one for your axle weight/tyre sizes. You need to scroll down to around page 80ish.

http://blobs.continental-tires.com/www8/servlet/blob/85806/e0854f2c7866c64da551474b998ef8b3/download-technical-databook-data.pdf

 

[Otter Spotter]

I gave them the weights they came back with 42 psi on the front 59 psi on the rear

Sounds reasonable, I have continental and they gave me 54 psi front and 51 rear.

 

[denisejoe]

Toyo ho9 had a max pressure of 70 psi check on the side wall of the tyres, only ran at 55psi

 

[Langtoftlad]

I gave them the weights they came back with 42 psi on the front 59 psi on the rear

Whenever these discussions come up - I always post the pressures Bridgestone gave to me, based on 1740 Front, 1750 Rear which was 53psi...
A lot lower than many seem to run their tyres at.

 

[Langtoftlad]

If you post your weights - I'll run them via a nifty little spreadsheet I got from Techno
[...and tyre load index/max pressure]
Although 'generic' I bet it's suggestion wont be far off Toyo's recommendations

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[Pausim]

My handbook gives pressures below 80psi/5.5bar, even for Michelin tyres.

 

[Howard H]

Similar pressures to what Continental recommends for ours.
I don’t think Toyo do a chart but check this Continental one for your axle weight/tyre sizes. You need to scroll down to around page 80ish.

http://blobs.continental-tires.com/www8/servlet/blob/85806/e0854f2c7866c64da551474b998ef8b3/download-technical-databook-data.pdf

wow that is a comprehensive list thanks

 

[Howard H]

If you post your weights - I'll run them via a nifty little spreadsheet I got from Techno
[...and tyre load index/max pressure]
Although 'generic' I bet it's suggestion wont be far off Toyo's recommendations

Thanks , I doNot have a weighbridge weight but work on it’s going to be loaded to the max which would be front 1650 kg and the rear 2200 kg .

 

[tonyidle]

When one buys a new vehicle in most cases the General Data section of the Handbook specifies the correct size of tyres and the pressure to which each should be inflated. The Handbook rarely if ever specifies the manufacturer of the tyres that must be used. If the vehicle manufacturers stated inflation pressure applies to any (correctly sized) tyre that's installed then so should a more personalised set of pressures derived from axle weight.

 

[Howard H]

Thanks , I doNot have a weighbridge weight but work on it’s going to be loaded to the max which would be front 1650 kg and the rear 2200 kg .

I forgot tyre load 121R

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[Langtoftlad]

So a little higher than Toyo's recommendation but not a million miles away - so IMHO quite believable.

 

[Howard H]

View attachment 431015

So a little higher than Toyo's recommendation but not a million miles away - so IMHO quite believable.

Thanks Stephen,will give it a go

 

[thebriars]

There is a straightforward formula for calculating tyre pressures. It relies on max tyre pressure stated on tyre, tyre load figure and axle weights. Works with any tyre. Its there on Google somewhere.
Try vwjim.co.uk

 

[Pausim]

There is a straightforward formula for calculating tyre pressures. It relies on max tyre pressure stated on tyre, tyre load figure and axle weights. Works with any tyre. Its there on Google somewhere.
Try vwjim.co.uk

The TyreSafe one that comes at the top of the Google search is rubbish. I entered my tyre details and axle weights and got 80psi on the rear axle, which is a lot higher than my handbook says. I then halved the axle weight and still got 80psi on the rear. Seems to default to 80psi whatever weight I enter, clearly falls into the chocolate teapot category.

 

[thebriars]

The TyreSafe one that comes at the top of the Google search is rubbish. I entered my tyre details and axle weights and got 80psi on the rear axle, which is a lot higher than my handbook says. I then halved the axle weight and still got 80psi on the rear. Seems to default to 80psi whatever weight I enter, clearly falls into the chocolate teapot category.

Not the tyresafe one that tells me my tyres are overinflated. Its an actual formula. You plug in the data and work it out yourself. Gave a sensible figure with my van.

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[Howard H]

There is a straightforward formula for calculating tyre pressures. It relies on max tyre pressure stated on tyre, tyre load figure and axle weights. Works with any tyre. Its there on Google somewhere.
Try vwjim.co.uk

That is one complicated calculation will acquire a calculator tomorrow <Broken link removed><Broken link removed>

 

[thebriars]

That is one complicated calculation will acquire a calculator tomorrow <Broken link removed><Broken link removed>

When you look, its not that complicated. Use your phone.

 

[Sandancers]

My handbook gives pressures below 80psi/5.5bar, even for Michelin tyres.
View attachment 430975

After having our MH weighed, fully loads, rang Continental Tyres, spoke to a man and he recommended 3.25B all round, so not far off yours. Mind, I tend to run them at 3.5B to account for all the extra beer when we go to France !

 

[Pausim]

After having our MH weighed, fully loads, rang Continental Tyres, spoke to a man and he recommended 3.25B all round, so not far off yours. Mind, I tend to run them at 3.5B to account for all the extra beer when we go to France !

I inflate them a little over the given pressures as well.

 

[clanjones]

Some of you will know I have been looking at all season tyres, identified a Continental camper tyre exists but when I contacted them and gave them my axle loading 80 psi on the rear! No thanks. Back to square 1!

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[Yorick]

Call me old fashioned, but I'd prefer the info from a tyre manufacturer than some stranger on the internet.

If you had an accident, with the wrong tyre pressures, who would the courts believe ?

 

[Hettie's Crew]

Some of you will know I have been looking at all season tyres, identified a Continental camper tyre exists but when I contacted them and gave them my axle loading 80 psi on the rear! No thanks. Back to square 1!

Our rear axle pressure was 80 psi when we were on 215/70 15 Continental Campers. Going up a size to 225/70 15 and swapping to Continental 4Season brought that down 65psi, for a much more comfortable ride.
All done with advice from the ever helpful Continental tech.

https://blobs.continental-tires.com/www8/servlet/blob/2227928/c555b253939be0c9946999d02db4624d/vancontact-4season-pfb-data.pdf

 

[PeteH]

I have Conti R235/65 R-16 CP tyres, which for Front 1620Kg they recommend 44psi, And Rear 1840Kg 58psi. At the moment they are actually 48 and 62 psi respectively They tend to increase by up to 10psi at running speed according to the Tyrepal readout.