Tyre size - sanity check please?!

[RubyOptics]

Hi all,

Our van is currently fitted with a mish-mash of old michelin camper tyres on the rear and some unheard-of-brand fronts which seem new. I don't trust either of them and so we will be replacing with 4 nice new pieces of rubber. As Poland can have rather snowy winters, we feel more comfortable fitting a dedicated "winter" tyre, even though it won't be marked as a camper specific tyre. In the summer we plan to fit a dedicated camper tyre but that's a thread that can wait for some sunshine!

From the test we have looked at (autobild and ADAC) it seems that the Bridgestone Blizzak LM005's are a really good performer in both wet and snowy conditions, and so we would like to fit these. My current monstrosities are 215/75/R16. The closest Blizzak size I can find are 215/70/R16.

My question is this...is that 5mm of sidewall height going to make any appreciable difference and can I have some reassurance that this will be ok to fit (as long as you think it is of course!)?!?!

 

[Dave100456]

The 70 and 75 is the aspect ratios of the tyres and is an expression of a percentage of its width. So is it not the case that you are “loosing” 5% of 225 which is 11mm and not 5mm as you say.
Sorry can’t help with the question as to what difference it will make to the handling. I’d have thought the ride will be a little firmer and there will be less tyre roll on lateral loading.
Cheers
Dave

 

[tonyidle]

I’d have thought the ride will be a little firmer and there will be less tyre roll on lateral loading

So would I - and it's not likely you'll notice that in Winter anyway.

 

[Dave100456]

Sorry I don’t have the experience/knowledge to call that one.

 

[AXO66]

Just check the load weighting of the tyre.

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[Dave100456]

I’d agree with youth at the tyres may well be okay, but it pains me to say the worry I’d have is with my insurer if I had to make a claim for a vehicle that had tyres of a non standard size, even though they may not have been a contributory factor.

 

[Raul]

To maintain the same circumference, if you loose 5 on the side wall, you will need to increase the width to make up for the percentage. I would safely go for 225/70 replacing the 215/75. But there is a downside. On snow the narrow the tyre the better the grip. My van takes 205-215 and 225 width. My winter tyres are 205’s and summer 215’s respectively.

 

[EuroTrotters]

A few quick answers.

If the original tyre size is as you state, you will be reducing the tyre size. in most cases, you would be better increasing slightly. But no more than around 4-5%. Hull climbing, final drive etc. Can get complicated.

My preference of tyre is Michelin Alpin winter.

I would not bother with specific Camper tyres in Summer.

 

[Raul]

I’d agree with youth at the tyres may well be okay, but it pains me to say the worry I’d have is with my insurer if I had to make a claim for a vehicle that had tyres of a non standard size, even though they may not have been a contributory factor.

Vehicle tyre size is plated on the door. Most of the time is homologated for 2-3 size combination. The insurer all needs to know if is fitted with what the manufacture has homologated the vehicle with.

 

[Raul]

A few quick answers.

If the original tyre size is as you state, you will be reducing the tyre size. in most cases, you would be better increasing slightly. But no more than around 4-5%. Hull climbing, final drive etc. Can get complicated.

My preference of tyre is Michelin Alpin winter.

I would not bother with specific Camper tyres in Summer.View attachment 433710

Try a combination of 215/75/16 against 225/70/16 , that would give closer results for the circumference

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[EuroTrotters]

Try a combination of 215/75/16 against 225/70/16 , that would give closer results for the circumference

just need to watch clearances and wheel J size

 

[RubyOptics]

Many thanks for all your replies. Interestingly, a quick internet search shows the standard tyre size for the 2.8 JTD being 225/60R16. I'll double check the plate on the van tomorrow and see if this shows anything different as well!

 

[SpeedyDux]

That revolutions per mile comparison also suggests that the Size 2 tyre will make the speedo over-read by about 1%. Likewise the odometer mileage. Not that such small inaccuracies matter much.

 

[RubyOptics]

That revolutions per mile comparison also suggests that the Size 2 tyre will make the speedo over-read by about 1%. Likewise the odometer mileage. Not that such small inaccuracies matter much.

I also need a replacement speedo cable fitted (the needle jumps around at anything over about 40km/h) so right now I wouldn't even notice a 20% difference

 

[Emmit]

From experience of driving a '225' tyre as opposed to a '215' in snow, I don't think such a marginal difference in width would make much of a difference. We still climbed the hill to Bourg Madame two winters ago. (Mrs Emmit still has nightmares.)

The benefit of increasing the width of the tyre is that it will invariably increase the load index.
Whilst this might not make an actual difference to your ability to actually carry more, it will increase the margin between the limit at which you carry and the maximum load.
We changed from 215 to 225 and that increased the load index higher and away from the paltry 60kgs from our max rear axle load. This eased the pressure on the tyre when coming down some of the french and Spanish 'Sleeping Policemen' at the entry and exit from villages.

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[Tyrefixer]

In the tyre industry it is noted that it is ok to go one size up but never one size
smaller.

 

[pappajohn]

I also need a replacement speedo cable fitted (the needle jumps around at anything over about 40km/h) so right now I wouldn't even notice a 20% difference

You don't state the vehicle age but I would expect an electronic speedo, electronic sensor rather than cable driven

 

[Lenny HB]

My current monstrosities are 215/75/R16.

internet search shows the standard tyre size for the 2.8 JTD being 225/60R16.

Neither sound right normally on 16" rims they are 225/75 R16.

 

[Lenny HB]

The closest Blizzak size I can find are 215/70/R16.

They only have a load rating of 100 which is 800 kg far too low for a Motorhome.

 

[Pete5996]

I did post this info in another thread a week or two back but if anyone is looking for a winter tyre with CP rating for MHs, Continental seem to have recently released the VanContact Camper. Note the subtle difference in name from their summer tyre, the VancoCamper, which I have fitted at present.

It has the 3PMSF and CP symbols, so should be acceptable in any European country. I've got plenty of life left in my existing tyres but will certauinly consider them when replacement time arrives.

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[Westbarn1]

I did post this info in another thread a week or two back but if anyone is looking for a winter tyre with CP rating for MHs, Continental seem to have recently released the VanContact Camper. Note the subtle difference in name from their summer tyre, the VancoCamper, which I have fitted at present.

It has the 3PMSF and CP symbols, so should be acceptable in any European country. I've got plenty of life left in my existing tyres but will certauinly consider them when replacement time arrives.

I have these tyres fitted as OE on my Hymer, only driven back from Frankfurt recently in Winter conditions (snow/sleet/ rain) but they seem okay to me

 

[SUGGY]

I've had Khumo Winter Portran on the last 2 Van's .
I went up to
225/75/16 ..the side walls on these are 121/122 a lot thicker and more stable especially on cornering ..They have been great on snow and on muddy fields .
They are a lot quieter than the Continental Camper tyres I had . that were absolutely rubbish in the wet ....
I got them from openeo tyres London £95 delivered .
Been on 23.000miles and down to 6 mm now .

 

[Ian Bosman]

Hi all,

Our van is currently fitted with a mish-mash of old michelin camper tyres on the rear and some unheard-of-brand fronts which seem new. I don't trust either of them and so we will be replacing with 4 nice new pieces of rubber. As Poland can have rather snowy winters, we feel more comfortable fitting a dedicated "winter" tyre, even though it won't be marked as a camper specific tyre. In the summer we plan to fit a dedicated camper tyre but that's a thread that can wait for some sunshine!

From the test we have looked at (autobild and ADAC) it seems that the Bridgestone Blizzak LM005's are a really good performer in both wet and snowy conditions, and so we would like to fit these. My current monstrosities are 215/75/R16. The closest Blizzak size I can find are 215/70/R16.

My question is this...is that 5mm of sidewall height going to make any appreciable difference and can I have some reassurance that this will be ok to fit (as long as you think it is of course!)?!?!

The change from 215/75 to 215/70 is a different rolling radius meaning the speedometer will produce a false reading so do not do the change, especially at the front assuming front wheel drive.

 

[chaser]

Will these do the job?
<Broken link removed>

 

[Colinyellowspanner]

Check out the many Tyre SIZE comparison sites, there are lots. The sidewall percentage figure represents what proportion the sidewall is of the width of the tread. If you go up say, from 205 to 225 width you must reduce the sidewall from 55% to 50% to maintain the same rolling circumference (I’ve just done this on my car). The charts will tell you how far you can go. The load figure is also v important.

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[Lenny HB]

Will these do the job?
<Broken link removed>

The load rating is only 113, needs to be 116 or even better 121.

I recently fitted Toyo Observe Van 225/75R16 / 121 a winter tyre very pleased with them.

 

[Ian Kelly]

Why not consider the Michelin CrossClimate tyres for all year round use.

 

[Lenny HB]

Why not consider the Michelin CrossClimate tyres for all year round use.

You have not seen the thread about cracks appearing in them after only one or 2 years use then.

 

[minesapint]

A few quick answers.

If the original tyre size is as you state, you will be reducing the tyre size. in most cases, you would be better increasing slightly. But no more than around 4-5%. Hull climbing, final drive etc. Can get complicated.

My preference of tyre is Michelin Alpin winter.

I would not bother with specific Camper tyres in Summer.View attachment 433710

T would not trust that site, they cannot even spell Tyres correctly.

 

[EuroTrotters]

T would not trust that site, they cannot even spell Tyres correctly.

Reminds me of when Nexen Tire put a big advertising banner over Manchester City’s entrance road, Alan Turin Way. “Nexen Tire”. So many complaints it was changed at your request to “NEXEN Tyre” OR TYREs