# Tyre pressures



## Ramsey007

Hi all.

I have put two new tyres on the back of my van (hankooks). They have the same loading as the old michlins ( which are still on the front) but i think i may have a problem. Not sure if im paranoid but the van now seems to snake. When i looked at the new tyres the max pressure is 80 and suggested 72psi. Trouble is the max on the new tyres is 65 psi? I havent had chance to check the pressures but now a tad worried! Is it because i have different tyres front and rear and different psis thasts giving me my light frontend/dancing back end.

Cheers
rams.


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## Morgan-The-Moon

[align=justify]

Are the michs you bought "camping car tyres".


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## Ramsey007

The michs are originals and yeah they have camping tyres written on them. They will need to go aswell soon.


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## Techno100

How do front and rear tires LOOK to the eye in comparison to each other. Over inflated tires will look ROUND. Front and rear should at least look a similar shape and form the same footprint with a little flatness in contact with the ground.
The gradual increase of stuff in my van has led to my current pressures being 50 front and 70 rear and still the front look a little more round than the rear.


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## Ramsey007

Sorry original post wrong.
Old michs on front-max 80psi suggested 72
new hankooks on rear- max 65psi
both have same loading. New tyres have better speed rating.


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## Morgan-The-Moon

8) 8)

Hanocks??? Are you sure they are rated for the weight of your back end. I.E. Are the construction of the walls good enough!


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## peribro

I don't know what your axle weights are but 72psi for the front and 65psi for the back, looks high and low respectively. I have Continental tyres and with axle loadings of 1,800kg front and 2,400 rear, my tyres pressures are 50psi and 75psi respectively. Have a look at the download on the Tyre Safety site here and it will show you recommended pressures. You will need to have an idea of your axle loads though.


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## gaspode

My first reaction is that your front pressures are too high but you'd need to confirm this with your M/H manufacturer or tyre manufacturer.

Second observation is that I swapped from Michelin Camping tyres to a more conventional (Chinese made - can't remember the name) van tyre. Initial driving experience was that the 'van drove very differently and felt slightly "wobbly", presumably because the walls of the new tyres are more flexible than the Michelins. I believe the Michelin camping tyres have very inflexible sidewalls because they spend a long time standing fully loaded. I soon grew accustomed to the new feel and don't even notice it now.
I should add that the tyres I fitted have a higher load rating than the Michelins and are also 10 ply rating rather than 8 ply, also max inflation pressure is 80psi (I have around 75psi in the rear axle and around 60psi in the front).

The new tyres are much better than the Michelins on grass although the tread pattern looks very similar.

I think my plan of action would be to swap the new tyres to the front and reduce the pressure on the front axle.


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## wakk44

The sure way to check if your tyre pressures are correct is to go to a weighbridge,get the axle loadings,then contact the tyre manufacturer with all the tyre details,axle weights and ask for a recommendation.

I changed my tyres to continental vanco2's from michelin camping last year and the tyre pressures had to be reduced.After an e-mail to continental,who were very helpful and efficient,they recommended 45psi front and 55psi rear.


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## Ramsey007

Ok heres all the data:
Front Tyres (original from when I bought it)
XC Camping Michelin
2 polyester plies
3 Steel
2Polyester
7ply?
Loading:
single - 2270lb
double - 22150lb
max 80PSI 

Rears (new tyres)
Hankooks RA08 (some good reviews about them on here)
2ply steel
2poly
1nylon
2poly
States 8ply?
Max 65psi

Not sure whats in them as I dont have a gage but since fitted a t decent tyre place im hoping they are pretty high.

Some one asked what do they look like in comparison to the front.
The front walls are much flatter and the rears are rounder as if under more weight or less pressure in them.
Can 1 ply steel make that much difference?
Would changing the fronts to something similar change teh ride?
The manufacurer (door post) states 71psi, obviously I cant do this in the rears.
Have I bought the wrong tyres?
Im worried as i carry my two children round every weekend in my van and need it to be totally safe.

I live in the middle of cornwall so cant get to a weighbridge an to be honest wouldnt know what I was doing.
Thanks all

Rams.


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## Wizzo

Like others on here I would say that your front pressures are too high. Look at the tyre data sheet that Peribo suggests. For axle weights use the max weights as plated on your vehicle - usually found under the bonnet next to the original manufacturer's plate or maybe on the side of the van near the hab door.

This will at least give you a start. It's impossible to hazard a guess as to your actual weights but we will have to assume that you are under the maximum.

The pressures on the door pillars were put there before the van was converted and are usually well over the top. Also the pressure on the tyre walls is only for the USA market.

JohnW


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## JeanLuc

Given that you cannot get to a weighbridge and then ask the tyre manufacturer for advice, you can get the answers you need from the attached tables. I have extracted these from a Tyre Fact sheet, which is too big to upload as an attachment (these are apparently limited to 1MB). Firstly, identify the size and load index of your tyres. Then note the maximum axle loadings on the motorhome's plate.

Look at the load index table in the fact sheet and confirm that the load index of your tyres allows more than, or equal to, the maximum plated axle weights (load index weight capability x 2).
e.g. LI = 110 -> 1,060 kg per wheel, x 2 = 2,120 kg max load for the axle

Then consult the tables at the bottom of the page (the first is for standard van tyres, the second for Camping, or CP tyres).
Read down the first column until you find the correct tyre size and load index, then read across to your motorhome's maximum axle weight and note the inflation pressure at the top of the column.

If you habitually run the motorhome below its maximum loading, it is possible to lower the pressures for greater comfort, but to do this safely, you need to visit a weighbridge with your normal touring load onboard.


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## fdhadi

Hi Rams

Just a thought. What make & model is your m/h? Someone on here may have the same van and be able to help you with weights or tyre pressures.

We have an 04 Burstner A747 (tag). The Burstner book states that the front should be 5.5 bar (80psi) and both rear axles 3.5 bar (51psi).

The front at 5.5 feels very hard. The rear at 3.5 looks very soft. I find 5 bar front and 4 bar rear is a much better ride.


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## short-stick

What is the speed and load rating of the Hankooks and the Michelins?
In fact, what is the complete size, load and speed rating as stamped on each tyre.
For example 235/70 15 97p as an example....
And I highly recommend you get the rear tyre pressures checked before you drive the van again... There may only be 35psi in them!!


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## Ramsey007

Thanks all,hectic life and email updates stopped so only just saw the last replies. havent checked anything else yet but just wanted to say how great you all are! Owning something like this for the first time is daunting but people like you on hand gives real confidence.
Thank you.


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## Morgan-The-Moon

This may be of interest, I've seen all sorts of mismatched tyre configurations on my travels. My main thoughts on the information you have given is "safety first" wife and children! take no risks, from what you have written one assumes the original tyres were Michelin Camping. I copied the below off a tyre supplier site. I hope it may be helpful to you. 


Michelin launched the new Agilis Camping tyre – currently the only motorcaravan tyre on the market with an M+S marking – as part of the new Michelin Agilis range for medium and heavy vans.

The Michelin Agilis Camping provides motorcaravan drivers with the same benefits as the Agilis van range: long tread life, enhanced safety performance and reduced fuel consumption. Reduced fuel consumption means reduced CO2 emissions which, when coupled with 20% more mileage than its predecessor means this is one of the greenest tyres available to those who enjoy the great outdoors. 

The tyre’s three other main features are longevity, robustness and versatility. 

• It owes its longevity to the Durable Contact Patch, derived from the new Michelin Agilis which enables a useful life that extends over several seasons. Developed initially for truck tyres, Durable Contact Patch technology increases tyre life by optimising the tyre’s footprint. 

• The tyre’s robustness results from its reinforced, dual-casing architecture that allows for higher tyre pressure, and protected sidewalls. Each sidewall features eight protective shields that increase curb impact resistance. 

• Its versatility comes from the tread pattern and the rubber compound. The tread includes 30% more sipes and a 20% higher void ratio than the Michelin Agilis van tyres. The rubber compound delivers superior performance in a wide range of temperature conditions, ensuring optimal grip when occasionally used in mud or snow, on dirt tracks or in other difficult driving conditions. These rubber compounds also maintain superior grip, even when worn, and reduce wet braking distances by 3m compared to its predecessor. 

The European motorcaravan market is very dynamic, with an 8% growth of sales in 2006. Moreover, between 1995 and 2005 the yearly growth of sales in the motorcaravan market was more than 9.5%; Michelin has now produced a tyre that is set to satisfy this growing market. 

All sizes in the Michelin Agilis Camping range display the CP marking, indicating that they are certified for use on motorcaravans. This CP marking is provided by ETRTO (European Tyre and Rim Technical Organization) and it is specifically created for tyres capable of resisting occasionally severe driving conditions. The reinforced design of this tyre allows higher tyre pressure than the standard van tyre of the same size: 5.5 bar on the rear drive axlle.


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## Techno100

Gets my vote :thumbup: Why be a skinflint on the most important thing between you and oblivion :lol: 
Proud owner of 4 :wink:


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## DTPCHEMICALS

Thanks for this topic,
Yesterday I checked and increased all four RA08 to 5.5 bar (79.5psi)as per Autotrail handbook and the sticker inside the cab door.
In the morning I will reduce them.

They have done about 1000 miles at a pressure of 60 psi rear and 50 in the front. I have airide fitted mh is 3500kg. The ride seemed fine to me, but then again I jump into most vehicles and drive as is.


Dave p


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## DTPCHEMICALS

*Hankook tyres scoop coveted international award*

Hankook tyres scoop coveted international award 
Congratulations to Hankook tyres for picking up the Tyre Manufacturer of the Year award at the annual Tyre Technology International Awards for Innovation and Excellence 2011.

The South Korean tyres company impressed the award judges with its "advances over the past 12 months," and growth that may see the company become the world's fifth largest tyre maker over the coming years.

Jin Wook Choi, executive vice-president and European head of Hankook Tire, commented "2010 has been a very successful year for us and I accept this award with great joy.

"We consider this award as recognition towards our philosophy of sustainable global growth and of our commitment for our production sites.

My gratitude goes to all our staff, without whose exemplary commitment, such progress would not have been possible." 
The award was presented at a ceremony in Cologne, Germany, earlier this month and the runners up were Apollo Tyres and Bridgestone.

Dave p


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## Ramsey007

Thanks for the info. 
I know what your saying re trying to save money on something so important. It wasnt as much that as getting the best for my money. These cost me 174 quid fitted for 2 so not the cheapest. The thing is i suppose is if i had an accident because of the tyres 1 or 200 quids saving wouldnt mean a thing.
The point is though is these tyres are meant to do the job re their ratings and have good reviews on here so the issue maybe with pressures or the skinflint in me not changing all 4 which i will do now. I just dont want to buy another two if they arent right. I will report back today.
cheers rams.


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## DTPCHEMICALS

Don`t worry ramsey 
Hankook have been making tyres since 1941.
they are made to a specification and they are fit for purpose.
Son in law who drives our mh is sure that they stop quicker than the Michelins. They appear quieter too.
As for life expectancy, if they last 5 years i will be happy.

There are a couple of well known manufacturers products that I would not use.
I will be putting some on my works scudo when the time comes.

They are cheap because the labour costs in Korea are less.

That is the reason that M & S clothes are manufactured abroad.
Many other day to day items too

Dave p


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## DTPCHEMICALS

Contact for Hankook Tyres europe.

Contact
Hankook Tire Europe GmbH 
Europe Headquarters

Siemensstraße 5a
63263 Neu-Isenburg
Germany

Phone: +49 (0) 6102 81 49-0
Fax: +49 (0) 6102 81 49-100

E-Mail: [email protected]

Dave p

The RAO8 are made in Chine. Even cheaper labour rates.


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## fdhadi

Ford Cars are now fitted with Hankook tyres as standard.


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## Techno100

8) :lol:


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## Morgan-The-Moon

Well Rams, lots to consider. My personal experiences with the law enforcers in different EU. States, now makes me consider the ludricous.

Try explaining to an over zealous law enforcer at 11.00 o'clock on a dark rainy night that your tyres are considered to be the ones specified for your vehicle. He's stopped you because "he thinks" your tyres look slightly inflated. 

If your supplier is confident, they will not have a problem with giving you a specific document to cover any concerns you may have.

That document may be useful in a court of law should your vehicle be involved in a serious accident where engineers and experts are called as "expert witness" . In all circumstances there are pros and cons. In law there is definitive right and wrong, and opinions. Black and white, a document stating the tyres fitted as new, considered by the manufacturer / converter will cover you and allow you to sleep at night knowing you have done your best. 

Awards and backslapping by the industry to the industry are what they are to thinking people, "useless" when your in the mire. 

The two tyres you have bought may well be the bee's knees for your motorhome. Get the supplier to state it in writing and you've done your best.

Good Luck !

Moc,





:wink: :wink:


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## Ramsey007

Well interesting result today, drive to the garage and the vans backside was well loose ie turn left and right rear sags. Checked pressures and all wheels 65psi.
dropped 10 psi out of the fronts and the van was much better.
Im going to call and email hankook with my weights etc to feel safe next week.
I think my problems is though is that i have missmatched tyres. The fronts need replacing as perishing too.
i wasnt been a cheap skate getting hankooks, i just read on forums that they seem better. The skinflint in me was not changing all 4 which i will correct next week.
anyway, just drove back about 1hr 15mins from woolacomb to bude and there was very little temperature in the tyres so not running hot.
Will keep you updated.
rams


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## Techno100

Joking aside Hankook are fine, the major difference being they will deliver less mileage than Michelin but with a 5 year life cycle it may be irrelevant.


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## DTPCHEMICALS

Here is my reply from Hankook 


Dear Mr Pearson
Thank you for your enquiry about 215/70R15C 109/107R fitted to your Fiat Motor Home.

Concerning 217/70R15C 109/107R Hankook RA08

The above tyre specification of 109/107R is the load index number code, associated with the maximum load that a tyre can carry at the speed
Indicated by its speed symbol.
The first number represents the load in single wheel application, the second in a dual wheel application.

109 = 1030 kgs
107 = 975 kgs
R = 170 km/h (105.63 m.p.h. approx) this is a test capability based for the tyre to be run for a period of time.

So for a tyre fitted on the front axle = the weight it can carry is 1030 kgs per tyre ( 2 tyres per axle = 2,060 kgs) the recommended tyre pressure would be 65 psi.

If the tyre was fitted in a dual wheel fitment, 2 tyres per hub = 4 tyres per axle. The weight that the tyre can carry is 975 kgs per tyre.
4 tyres x 975 kgs = 3,900 kgs. (So if fitted to a rear axle on dual fitment the axle weight capabilities would be 3,900 kgs) the recommended tyre pressures per tyre would be 65 psi.

Hankook tyres does not recommend fitment to vehicles where high pressures are required or designated on applications that are above the tyre manufacturers design capabilities of weight, or pressure specification.

Tyres designated with high pressure cababilities have a CP designation indicated the on the sidewall and must also be fitted with high pressure valves.

I hope that this has answered your enquiry.




Chris Baxter
Technical Service Manager
Hankook Tyre UK Ltd



Dave p


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## Ramsey007

Confused now. I'm sitting at the garage about to have the front changed? What shall I do?


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## Ramsey007

well I went through everything with the bloke at the garage and stuck some more Hankooks on the front.
We looked at the email and loadings and all still looked fine.
I have to say what Im driving on now is far safer than before but that was through ignorance!
My fronts were well persihed too, I had no idea how old they were or how to tell and the lad told me, 2001!!! A bit past their sell by date, they are older than my van.
The van feels great again with its new fronts on. I had a play with pressures as I think teh old tyres had about a 7psi balance between them and by doing the same with these she handles great again.
I have to say smoother and quieter but not suprised with 10yr old tyres on!

Thanks all for your help as ever, I know its opened a bit of debate but "Im" confident Im safe and certainly safer.

Rams.


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## DTPCHEMICALS

Good Now you can sleep tonight.
I am off to Holland tomorrow so it wil be the first time Hankooks have done more tha 75 miles per trip.
I shall let you know how I get on.

dave p


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