HELP - Legal higher tyre pressures for Ducato Maxi 150 on Michelin 225/75 R16 X energy, please
MDE said
05:33 PM Jan 1, 2017
Hi
We have a Ducato Mulivan 150 van conversion with 225/75 R16 Michelin X Green Eco light truck tyres The imprinted Max Speed and Cold Pressure on the tyre wall is stated as116km/h at 80 psi.... The Fiat plaque states recommended 450 kPa front and 550 kPa back full load.
The van is bouncing and bumping at these pressures and NOT handling very well... Can somebody recommend legal pressures for a 4,100kg van with the above tyre, please?
TheHeaths said
06:03 PM Jan 1, 2017
MDE,
copy of my post to the thread re van tyre pressures on Techie forum. may give you somewhere to start for setting yours.
"Our van is a tandem axle, weighing 2750 kg fully loaded, so based on that, the AVERAGE load on each tyre is 690 kg near enough (I know not exactly and this takes NO account of tow ball load, but gives a good start point)
Our tyres on the van show Maximum Load per tyre to be 925 kg at 44 PSI. They are 235/75R 15 AT tyres.
Thus our vans weight is 690/925 as a ratio/%age of maximum load, or 74.6% (near enough to 75%)
Thus I started at 75% of 44 psi, or 33 psi.
I run the tyres at 36 psi, and have found this to be a good pressure during our trips, but do drop a little on dirt, to around the 30 psi. This has been fine over the 30000 kms we have towed the van, and over that period we have had no problems with tyres. I used the same process on our previous van, and towed that some 25000 kms without incident."
PeterD said
10:05 PM Jan 1, 2017
MDE, are you asking about increasing your tyre pressures? If you increase your tyre pressure you will make it ride rougher.
The maximum tyre pressure and load carrying capacity are embossed on the side of they tyre. Have a look there.
Hey Jim said
10:17 PM Jan 1, 2017
Hi MDE,
What does your compliance plate on the bus read for the tyres, Verses the tyres that are on it.?
Jim
Woody n Sue said
09:35 AM Jan 2, 2017
Go to a tyre reseller they will be the best advice you can get and they won't mind giving that advice either they have the experience to advise.
For mine a little 4-5 psi is much better that 4-5 psi under tyre runs cooler
Not saying advice here is not good but it's one persons experience the tyre bloke has experiance with hundreds of customers
Here on the farm people with the radial tractor tyres are told ( by tractor dealers ) to run them at 5-6 psi for max traction which is all very good if you are prepared to buy a new set of 8 tyres every 1800 to 2000 hours at around $2000 to $3000 per tyre but if you want them to last 4000 plus hours blow them up to 18 - 20 psi ( advice from tyre reseller ) he has seen it too often farmers complaining that there tyres are stuffed too soon
Woody
WAssa41 said
09:42 AM Jan 2, 2017
Ian is correct in his reply using the percentage system. As a further check you can use the 5psi system as a further check. If your tyres are at the correct pressure when cold they should increase by about 5psi after running for a bout an hour. If the go higher than 5psi then your cold pressure is to low and if they are under the 5psi then the cold pressure is to high. Please remember this just a GUIDE.
Wassa
MDE said
10:08 PM Jan 2, 2017
Thank You all for your input... Have to do some more calculations....
We just had the motor home on a weigh bridge yesterday afternoon and it appears to be only about 3,800 kg full load...
eric2011 said
02:29 PM Jan 3, 2017
My Fiat Ducato handbook and dealer recommendation is 80 psi. I have no need to muck around with the recommendations. I weigh in at around 4250 all up
macka17 said
09:14 AM Jan 4, 2017
I think I'd start at around 38lb and drive for an hr. recheck and do the 4\1\2 lb variation check.
But I don't think I'd go below 35 front with that front end.
It iS very accurate regarding tyre longevity and traction.
Thousands of 4WDers used it for decades.
Most of us Older vanners\long dist boat haulers too.
Harder the tyre. More the longevity. Rougher the ride. with minimum traction when up there.
Those high pressures to suit MFG's only basically..
Comfort\grip. or longevity. Take your pick.
My Patrol with 3 ton van ran 32\35ish ish with van 35\38ish on highway.
32 or 33 all round by itself. 25to28ish on corrugations
Somebody else's car in mud and sand.
Sometimes just 32 all round for comfort depending on tyres. and 35\36 with van if lazy.
Everybody had differing ideas. Try the 4 1\2 lb trick first. then others if not suiting you.
Some like and swear by. real hard.. too bumpy for me.
-- Edited by macka17 on Wednesday 4th of January 2017 09:16:54 AM
Aus-Kiwi said
10:00 AM Jan 4, 2017
Our motorhomes rear tyres especially are recommended to run 90 Lb . On out back roads the harshness through cabin, body is increadable .. I found one squeak at microwave which drove me CRAZZY ( Crazier ?) until Mrs put a little plastic packing in cabinet . I rang Michelin They just said the recommended pressure are 90 to 100 lb ., I lowered tyres to 45 inside /50 lb outside . Then checked tyre temps after 10 klrs . In 38* ambient 100 Kph . I could easy touch the tread . The ride, harshness has much much improved !! Keep in mind before that I replaced the Bilstien shocks !! $$$ ..Made little difference .. Simple things often work the best !! Seems tyre pressures are set to max load, speed etc .. The front tyres I lowered to 70lb ..
-- Edited by Aus-Kiwi on Wednesday 4th of January 2017 12:00:19 PM
-- Edited by Aus-Kiwi on Wednesday 4th of January 2017 12:01:47 PM
Tony Bev said
01:39 PM Jan 4, 2017
Hello MDE
Do not over inflate the pressure which is stamped on your tyre
I have a 2006 Fiat Ducato motorhome AGG of vehicle is 3850 Kg, and I am slightly over/under this weight, depending on fuel/water load
Tyres are Michelin Agilis light truck tyres 215 75 R16 on rear max pressure 65 PSI, I run them at 65 PSI and they look as though they could do with a bit more pressure 225 75 R16 on front 80 PSI max, I run them at 75 PSI, they also look as though they can do with a bit more pressure Running at these pressures, I have no bounce
As a side note the recommended tyres for my vehicle are 215 75 R16 Michelin Camping type tyres Camping tyres have a stiffer side wall, as RV's are noted for being laid up for many weeks/months at a time I was unable to purchase campervan type tyres in Australia
Higher tyre pressure will give better fuel consumption but a bumpy ride Slightly lower pressure than recommended will give a nicer ride, but you will use more fuel
I shall let the experts explain about lack of grip, on under and over inflated tyres, which does not affect me, as I drive to the conditions, as I see/find them
Hope that this info is useful to you
macka17 said
02:34 PM Jan 5, 2017
30 to 45lbs will give a safe. comfortable economical ride
to 90% of the veh's most use.
apart from Heavy commercial. Motorhomes etc.
Yrs ago. from memory.
All the semi's I drove, and flatbeds ran at 90lb.
a bit more on steers.
Aus-Kiwi said
03:47 PM Jan 5, 2017
Yes and tyres where possibly 22" payload was way over 6 ton loaded . Also ride or chassis harmonics don't matter too much.
Bigger dia, higher profile tyres help !!
GerryP said
04:01 PM Jan 5, 2017
Firstly, you cannot compare tractor tyres or big truck tyres to those on a car, van or caravan - they are different construction and built for different duties.
Secondly, you cannot just inflate to either what's on the vehicle placard (as you may well have a different style of tyre fitted) or what is stated on the tyre as a maximum for maximum load.
As already mentioned here, you need to read what's on the tyre, then proportion it to the actual load on EACH tyre. At the very least, weigh each axle of your van separately, while loaded, so you know what each tyre is supporting, then proportion that out to the stampings on the tyres fitted.
If your van is already bouncing around, I have little doubt that you are over inflated. Doing the calc's above will verify that and show you what pressures you should be running.
The 4 psi rule is also somewhat outdated due to tyre construction changes over time. Certainly with heavier 4WD tyres (A/T, M/T LT tyres) it is not unusual for the pressures to rise some 6 to 8 psi at proper cold inflation pressures. Which reminds me... all pressures quoted and calculated are cold inflation pressures, so those pressures will of course rise as the tyres warm up..
Hi
We have a Ducato Mulivan 150 van conversion with 225/75 R16 Michelin X Green Eco light truck tyres
The imprinted Max Speed and Cold Pressure on the tyre wall is stated as116km/h at 80 psi....
The Fiat plaque states recommended 450 kPa front and 550 kPa back full load.
The van is bouncing and bumping at these pressures and NOT handling very well...
Can somebody recommend legal pressures for a 4,100kg van with the above tyre, please?
MDE,
copy of my post to the thread re van tyre pressures on Techie forum. may give you somewhere to start for setting yours.
"Our van is a tandem axle, weighing 2750 kg fully loaded, so based on that, the AVERAGE load on each tyre is 690 kg near enough (I know not exactly and this takes NO account of tow ball load, but gives a good start point)
Our tyres on the van show Maximum Load per tyre to be 925 kg at 44 PSI. They are 235/75R 15 AT tyres.
Thus our vans weight is 690/925 as a ratio/%age of maximum load, or 74.6% (near enough to 75%)
Thus I started at 75% of 44 psi, or 33 psi.
I run the tyres at 36 psi, and have found this to be a good pressure during our trips, but do drop a little on dirt, to around the 30 psi. This has been fine over the 30000 kms we have towed the van, and over that period we have had no problems with tyres. I used the same process on our previous van, and towed that some 25000 kms without incident."
MDE, are you asking about increasing your tyre pressures? If you increase your tyre pressure you will make it ride rougher.
The maximum tyre pressure and load carrying capacity are embossed on the side of they tyre. Have a look there.
Hi MDE,
What does your compliance plate on the bus read for the tyres, Verses the tyres that are on it.?
Jim
For mine a little 4-5 psi is much better that 4-5 psi under tyre runs cooler
Not saying advice here is not good but it's one persons experience the tyre bloke has experiance with hundreds of customers
Here on the farm people with the radial tractor tyres are told ( by tractor dealers ) to run them at 5-6 psi for max traction which is all very good if you are prepared to buy a new set of 8 tyres every 1800 to 2000 hours at around $2000 to $3000 per tyre but if you want them to last 4000 plus hours blow them up to 18 - 20 psi ( advice from tyre reseller ) he has seen it too often farmers complaining that there tyres are stuffed too soon
Woody
Ian is correct in his reply using the percentage system. As a further check you can use the 5psi system as a further check. If your tyres are at the correct pressure when cold they should increase by about 5psi after running for a bout an hour. If the go higher than 5psi then your cold pressure is to low and if they are under the 5psi then the cold pressure is to high. Please remember this just a GUIDE.
Wassa
We just had the motor home on a weigh bridge yesterday afternoon and it appears to be only about 3,800 kg full load...
I think I'd start at around 38lb and drive for an hr.
recheck and do the 4\1\2 lb variation check.
But I don't think I'd go below 35 front with that front end.
It iS very accurate regarding tyre longevity and traction.
Thousands of 4WDers used it for decades.
Most of us Older vanners\long dist boat haulers too.
Harder the tyre. More the longevity. Rougher the ride.
with minimum traction when up there.
Those high pressures to suit MFG's only basically..
Comfort\grip. or longevity. Take your pick.
My Patrol with 3 ton van ran 32\35ish ish with van
35\38ish on highway.
32 or 33 all round by itself.
25to28ish on corrugations
Somebody else's car in mud and sand.
Sometimes just 32 all round for comfort depending on tyres.
and 35\36 with van if lazy.
Everybody had differing ideas.
Try the 4 1\2 lb trick first. then others if not suiting you.
Some like and swear by. real hard.. too bumpy for me.
-- Edited by macka17 on Wednesday 4th of January 2017 09:16:54 AM
Our motorhomes rear tyres especially are recommended to run 90 Lb . On out back roads the harshness through cabin, body is increadable .. I found one squeak at microwave which drove me CRAZZY ( Crazier ?) until Mrs put a little plastic packing in cabinet . I rang Michelin They just said the recommended pressure are 90 to 100 lb ., I lowered tyres to 45 inside /50 lb outside . Then checked tyre temps after 10 klrs . In 38* ambient 100 Kph . I could easy touch the tread . The ride, harshness has much much improved !! Keep in mind before that I replaced the Bilstien shocks !! $$$ ..Made little difference .. Simple things often work the best !! Seems tyre pressures are set to max load, speed etc .. The front tyres I lowered to 70lb ..
-- Edited by Aus-Kiwi on Wednesday 4th of January 2017 12:00:19 PM
-- Edited by Aus-Kiwi on Wednesday 4th of January 2017 12:01:47 PM
Hello MDE
Do not over inflate the pressure which is stamped on your tyre
I have a 2006 Fiat Ducato motorhome AGG of vehicle is 3850 Kg, and I am slightly over/under this weight, depending on fuel/water load
Tyres are Michelin Agilis light truck tyres
215 75 R16 on rear max pressure 65 PSI, I run them at 65 PSI and they look as though they could do with a bit more pressure
225 75 R16 on front 80 PSI max, I run them at 75 PSI, they also look as though they can do with a bit more pressure
Running at these pressures, I have no bounce
As a side note the recommended tyres for my vehicle are 215 75 R16 Michelin Camping type tyres
Camping tyres have a stiffer side wall, as RV's are noted for being laid up for many weeks/months at a time
I was unable to purchase campervan type tyres in Australia
Higher tyre pressure will give better fuel consumption but a bumpy ride
Slightly lower pressure than recommended will give a nicer ride, but you will use more fuel
I shall let the experts explain about lack of grip, on under and over inflated tyres, which does not affect me, as I drive to the conditions, as I see/find them
Hope that this info is useful to you
to 90% of the veh's most use.
apart from Heavy commercial. Motorhomes etc.
Yrs ago. from memory.
All the semi's I drove, and flatbeds ran at 90lb.
a bit more on steers.
Firstly, you cannot compare tractor tyres or big truck tyres to those on a car, van or caravan - they are different construction and built for different duties.
Secondly, you cannot just inflate to either what's on the vehicle placard (as you may well have a different style of tyre fitted) or what is stated on the tyre as a maximum for maximum load.
As already mentioned here, you need to read what's on the tyre, then proportion it to the actual load on EACH tyre. At the very least, weigh each axle of your van separately, while loaded, so you know what each tyre is supporting, then proportion that out to the stampings on the tyres fitted.
If your van is already bouncing around, I have little doubt that you are over inflated. Doing the calc's above will verify that and show you what pressures you should be running.
The 4 psi rule is also somewhat outdated due to tyre construction changes over time. Certainly with heavier 4WD tyres (A/T, M/T LT tyres) it is not unusual for the pressures to rise some 6 to 8 psi at proper cold inflation pressures. Which reminds me... all pressures quoted and calculated are cold inflation pressures, so those pressures will of course rise as the tyres warm up..