When to change tyres ?

Feel free to ignore what I say
Done!

cibaker wrote:Thank for all the replies, Caraman I will check my tyres when I get home from work(hopefully in time to watch the rugby).

Definitely the rugby first.  If your tyres have been changed its worth checking the manufacture date on all your tyres including the spare and importantly what they have been changed to.  You may find that the manufacture date is on the inward facing sidewall which makes it harder to see/find.

I'm afraid that I usually reach to the back of the supermarket shelf for the freshest loaf of bread and, on that same principle, when I changed the tyres on both my vehicles a few months ago I specified no older than three (3) months, and that is what I got, with no moral issues inferred by the tyre dealers concerned. Did I feel guilty? Not in the least! I was buying "NEW" tyres. And even if it might cost 10% more per corner to find newer ones what the hell? Tyres are your only contact with the road (hopefully) and one of the biggest safety concerns when driving. 

I have been told by experts that small surface micro-cracking adjacent to tread blocks is not that major a risk on say a half worn tyre, but of course they need watching and they are definite symptoms of ageing. They tend to reflect differential stresses at "hard" spots in the moulding of the outer casing (where thick meets thinner). I worry more about delamination of the plys, which often can't be seen, and which I am told is an increasing issue given the UK's potholed roads and deliberate obstructions. Once the casing starts to delaminate the tyres run much hotter (I guess the loose plys rubbing together = friction) and degradation is a downward spiral. That is just one of the reasons why I favour all-terrain tyres: they are built to take more abuse, witting or unwitting, such as deformation when rock climbing. Sharp edged potholes walloped at speed must place phenomenal stresses on the internal structure of tyres, especially stiff walled van tyres working close to their load limits all the time.

I took this photo the other day.  I think the photo makes it look worse than it is.  You really have to search for it on the tyre.  As I have proven on my last 2 MOTs, its unlikely to spotted unless I draw it to the examiner's attention.

[You must be registered and logged in to see this link.]

Update on my tyres, I have just checked and they are dated 0813 so I guess I should change them.
It is a pity because I have examined them thoroughly and there is no sign of cracking anywhere. 
I will try to source replacements next week and I think I will stick with Bridgestone Duravis.
This has been a very informative post (despite a little bickering) so thank you all for the information.

cibaker wrote:Update on my tyres, I have just checked and they are dated 0813 so I guess I should change them.
It is a pity because I have examined them thoroughly and there is no sign of cracking anywhere. 
I will try to source replacements next week and I think I will stick with Bridgestone Duravis.
This has been a very informative post (despite a little bickering) so thank you all for the information.

So they are 11 years old!  Bridgestone Duravis are standard Commercial (C) van tyres.  Is this what is currently fitted?  What's their size and load index?

Presumably they are the original tyres supplied by Autosleeper. They are Bridgestone Duravis 255 70 15 C tyres.

cibaker wrote:Presumably they are the original tyres supplied by Autosleeper. They are Bridgestone Duravis 255 70 15 C tyres.

255 seems too wide, should it read 225?

Peter, my bad you are correct. I should have put my glasses on. 225 70 15 c

cibaker wrote:Presumably they are the original tyres supplied by Autosleeper. They are Bridgestone Duravis 255 70 15 C tyres.

Thanks.  The 225/70 R15 is 8 ply with a 112 load index.  If the cold tyre pressures shown on the C pillar are 4.5 bar or below, the van will have been supplied with C tyres.  My current tyres are 215/70 R15 CP with a lower load index of 109.  I intend to replace them with the same size and load index as yours but stay with CP which limits the choice to the Michelin CrossClimate Camping.

So fellow forum members, this rubber fetish debate has dragged on somewhat and is starting to confuse me, is there a general consensus for the following questions?  

Please give short simple definitive answers, no need for explanations. I accept a lot of folk will have personal preferences but I'm attempting (if possible) to gauge an average reply so people like me can go to the tyre shop and buy good tyres. 

1. Ideal frequency of change depending on a visual inspection for cracking, how many years?
2. Ideal Load Index for a 3500 rig?
3. All terrain or not? 
4. Recommended manufacturer?
5. Expected price per wheel fitted and balanced - ball park figure?

Thanks in anticipation

Monty-Plym wrote:So fellow forum members, this rubber fetish debate has dragged on somewhat and is starting to confuse me, is there a general consensus for the following questions?  

Please give short simple definitive answers, no need for explanations. I accept a lot of folk will have personal preferences but I'm attempting (if possible) to gauge an average reply so people like me can go to the tyre shop and buy good tyres. 

1. Ideal frequency of change depending on a visual inspection for cracking, how many years?
2. Ideal Load Index for a 3500 rig?
3. All terrain or not? 
4. Recommended manufacturer?
5. Expected price per wheel fitted and balanced - ball park figure?

Thanks in anticipation

Q1.  5 to 7 years.  If it's a weaker C tyre, if the vehicle spends significant periods out of use not on axle stands/jacks or without wheels covers and if tyre pressures are not checked & adjusted regularly - closer to 5 than 7.

Q2.  If there is any risk of the rear axle mass exceeding 1854 kg, higher than 109.  112 would be fine.

Q3.  If the van is used all year and on grass pitches, 4-season tyres rather than summer tyres.

Q4.  Any premium brand e.g Continental, Pirelli, Michelin

Q5.  It will depend on the size, load index, brand and type of tyre e.g. C or stronger but more expensive CP

You will still get 10 different opinions!

Mine is:

1  Every 6 or 7 years.

2 & 3 & 4  All terrain General Grabber AT3. Only available in 16" rim size, 121 load rating (single wheel). My van is plated now at 4500 kgs. on these tyres although actual weight is about 3700 kgs with wife & bikes). The version is specifically designed for motorhomes but can't remember exact size. (edit: here's the link:   https://www.tyrepress.com/2021/12/general-tire-tailors-grabber-at3-for-camper-market/)

Reasons:  Improved traction on grass & mud, stronger tyre overall, very smooth riding (eliminates lots of rattles!), anticipated very long life span 60k+ miles (I get 80+ on 4x4 cars with these). 

The downside is perhaps slightly increased fuel consumption but I am getting 29/30. I never clocked the consumption before changing tyres.

5.  I paid about £162 per corner fully fitted.

Monty-Plym wrote:So fellow forum members, this rubber fetish debate has dragged on somewhat and is starting to confuse me, is there a general consensus for the following questions?  

Please give short simple definitive answers, no need for explanations. I accept a lot of folk will have personal preferences but I'm attempting (if possible) to gauge an average reply so people like me can go to the tyre shop and buy good tyres. 

1. Ideal frequency of change depending on a visual inspection for cracking, how many years?
2. Ideal Load Index for a 3500 rig?
3. All terrain or not? 
4. Recommended manufacturer?
5. Expected price per wheel fitted and balanced - ball park figure?

Thanks in anticipation

What type, brand, size and load index do you currently have?

These - Warning this post contains naked pictures of a tyre

[You must be registered and logged in to see this link.]

They Pass the MOT, go round, brake when necessary and give me 28 mpg on average. No idea when they were manufactured as I cant see a date code anywhere, no idea what the load index is, they came with the van when I bought it new in March 2020 but due to issues preventing acceptance (Wheel arch plastic shroud hanging off) and Covid I didn't take delivery until July20.  Are these any good?  I do regularly take the van for a spin, maintain the correct pressures and visually check them for nails/screws/cracking, and where the van is parked they get no direct sunlight.

Monty-Plym wrote:I cant see a date code anywhere

I believe it is a legal requirement for a date code to be included for all tyres sold in the UK. Have you checked on the inside? There is (sadly) no requirement for the code to be on both sides, as I understand it. But the format makes it easy to spot once you know what you're looking for.

Monty-Plym wrote: no idea what the load index is

From the photo it's a little bit indistinct, but it looks like the spec is 125/15R16 116Q

The latter part means a load rating of 1250kg/tyre, and a speed rating of Q = 100MPH.

You have 225/75 R16 CP tyres with a load index of 116.  The only manufacturer of this tyre if you want 4-season is Michelin.  Your replacement tyres must not have a lower load index.  That said, I guess its load index is only as high as 116 so the vehicle can be up-plated.  Its not unlawful to fit a C Tyre but if you do you should inform your insurance company and every time you take out a new policy as the converted vehicle was type approved and fitted with CP tyres.  If you wanted to you could upgrade your 225/75 R16 CP to a 10 ply all-season CP tyre with a higher load index of 118 however I doubt this is necessary or even desirable as your rear axle MTPLM is currently only 2000 kg. Michelin and Continental are the only manufacturers of this tyre.

From what you have said, I would replace your tyres when they are 7 years old or earlier if they become worn or damaged.

Thanks for the info, if the rain ever stops I will crawl beneath the van to find the date stamp as it must be on the inside of the tyre.  I will never be going at 100mph in the van, it's a Fiat not a Merc.  Steady 60 to 65 is just right for me.

I guess it is easier to change the tyres like for like, that way there is no danger of the insurance being void.  I certainly won't skimp trying to save a penny when it comes down to tyres.

Monty-Plym wrote:...
I guess it is easier to change the tyres like for like, that way there is no danger of the insurance being void.  I certainly won't skimp trying to save a penny when it comes down to tyres.

Your current CP tyres are M&S rated, have a speed rating of Q and are primarily for summer use.  They are not all season.  I believe Michelin has replaced this tyre with their CrossClimate Camping which is M&S and all season and has a speed rating of R.  So not quite like for like but nearly so.  

Of the 3 manufacturers of CP tyres, Pirelli only make summer tyres (Pirelli Carrier Camper) and only one 16" with a narrower profile and lower load index (215/75 R16 113R 8 ply CP) than the tyre you have.  Michelin and Continental used to make summer CP tyres (only Michelin was M&S rated) but it appears they have both now gone over to all season (Michelin CrossClimate Camping & Continental VanContact Camper) which is a different tyre.  That said, if you search for their summer tyres (Michelin Agilis Camping & Continental Vanco Camper), stock still seems to be available.

One other question, does anyone know what the correct tyre pressure is for a 2014 Warwick Duo on 225 70 15 c tyres? I have read through all the documentation supplied and can't find any references regarding pressure.

cibaker wrote:One other question, does anyone know what the correct tyre pressure is for a 2014 Warwick Duo on 225 70 15 c tyres? I have read through all the documentation supplied and can't find any references regarding pressure.

Use TyreSafe's on-line calculator:

[You must be registered and logged in to see this link.]

The calculator uses the ETRTO pressures for an axle mass that is 10% higher to reduce the risk of any of the tyres being under inflated.  If you don't know your axle masses you could use your axle MTPLMs.  If they are 1850 kg front and 2000 kg rear, the calculator will give 58 psi for your front tyres and 64 psi for your rear tyres - 65 psi being your maximum permitted cold tyre pressure.  However, it is far better to load your campervan fully for a trip along with your passenger(s), a full fuel tank, full gas tank, full windscreen washer, full HW tank and the maximum amount of water you might carry in your fresh, grey and black water tanks and then measure your axle masses on a local weigh bridge.

I am surprised there is no tyre pressure label inside the cab passenger door on the C pillar.  If there is, it is likely to show the recommended pressures for when both axles are at the MTPLM which is not really what you want.

My tyres are from late 2017. Even though they look to have reasonable tread i will be changing these soon. Assume they are from new, van at 10k miles.  Front have flat spots, picked up when i had them balanced recently, vibration evident when driving and i went for easiest option ! 
Currently the tyres are van tyres, extra load but not campervan tyres. Assume tyre walls must have more strength for a campervan, will find out as i look for replacements.

The Bargee wrote:You will still get 10 different opinions!

Mine is:

1  Every 6 or 7 years.

2 & 3 & 4  All terrain General Grabber AT3. Only available in 16" rim size, 121 load rating (single wheel). My van is plated now at 4500 kgs. on these tyres although actual weight is about 3700 kgs with wife & bikes). The version is specifically designed for motorhomes but can't remember exact size. (edit: here's the link:   https://www.tyrepress.com/2021/12/general-tire-tailors-grabber-at3-for-camper-market/)

Reasons:  Improved traction on grass & mud, stronger tyre overall, very smooth riding (eliminates lots of rattles!), anticipated very long life span 60k+ miles (I get 80+ on 4x4 cars with these). 

The downside is perhaps slightly increased fuel consumption but I am getting 29/30. I never clocked the consumption before changing tyres.

5.  I paid about £162 per corner fully fitted.

Could you please tell me what size these tyres are ?

General Grabber AT3   235 65 R16C  Load Rating 121 (single wheel)