Go Back   English Forum Switzerland > Help & tips > Transportation/driving
Reply
 
Thread Tools Display Modes
  #1  
Old 20.10.2017, 15:51
Newbie 1st class
 
Join Date: Sep 2016
Location: Zurich
Posts: 23
Groaned at 0 Times in 0 Posts
Thanked 1 Time in 1 Post
Mountain High has no particular reputation at present
Smaller Winter Tyres for Van

I am about to buy a set of winter tyres for our Ducato based motorhome. I have heard that there is some advantage in going for a size smaller than your normal summer tyres but I don't really understand why. Can someone enlighten me!
Reply With Quote
  #2  
Old 20.10.2017, 15:56
JagWaugh's Avatar
Forum Legend
 
Join Date: Apr 2009
Location: Eglisau
Posts: 5,856
Groaned at 40 Times in 39 Posts
Thanked 11,046 Times in 4,352 Posts
JagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
I am about to buy a set of winter tyres for our Ducato based motorhome. I have heard that there is some advantage in going for a size smaller than your normal summer tyres but I don't really understand why. Can someone enlighten me!
Going down one size reduces the contact area. This works against the tendency to float on top of a layer of snow. (The weight of the camper stays the same, with a smaller footprint you have more pounds per square inch pushing the snow out of the way.)
Reply With Quote
  #3  
Old 20.10.2017, 16:14
gbn's Avatar
gbn gbn is offline
Forum Veteran
 
Join Date: Dec 2005
Location: Zollikon
Posts: 2,380
Groaned at 82 Times in 59 Posts
Thanked 1,668 Times in 833 Posts
gbn has a reputation beyond reputegbn has a reputation beyond reputegbn has a reputation beyond reputegbn has a reputation beyond reputegbn has a reputation beyond repute
Re: Smaller Winter Tyres for Van

I wouldn't do it though. It changes your

- engine to wheel gearing
- fuel economy (higher)
- speedo readings (higher)
- ABS sensors reading -> good luck
- Traction control sensor readings -> good luck

and it probably brings you closer to overloading your tyres smaller tyres carry smaller loads generally
Reply With Quote
  #4  
Old 20.10.2017, 16:16
st2lemans's Avatar
Forum Legend
 
Join Date: Dec 2010
Location: Lugano
Posts: 21,384
Groaned at 1,104 Times in 871 Posts
Thanked 24,097 Times in 11,527 Posts
st2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond repute
Re: Smaller Winter Tyres for Van

You want narrower, not smaller!

OD should remain the same (or close to it), in which case all of gbn's points fall by the wayside.

Tom
Reply With Quote
This user would like to thank st2lemans for this useful post:
  #5  
Old 20.10.2017, 16:21
baboon's Avatar
Forum Legend
 
Join Date: Apr 2007
Location: Rheintal
Posts: 2,916
Groaned at 90 Times in 79 Posts
Thanked 3,816 Times in 1,875 Posts
baboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
Going down one size reduces the contact area. This works against the tendency to float on top of a layer of snow. (The weight of the camper stays the same, with a smaller footprint you have more pounds per square inch pushing the snow out of the way.)
You will find contradicting opinions on that - on compact snow many say that wide tyres are better wheras in slush or deep fresh snow opinion seems pretty universal that narrower is better.

See here for example https://www.ktipp.ch/artikel/d/auch-...intertauglich/

I drive in the mountains a lot (ski tourer) but not on tracks and find reasonably wide tyres give better grip on the packed snow you typically find up there. Wide are also said to be better on wet roads

Narrower tyres might cost a little less....
Reply With Quote
  #6  
Old 20.10.2017, 16:28
JagWaugh's Avatar
Forum Legend
 
Join Date: Apr 2009
Location: Eglisau
Posts: 5,856
Groaned at 40 Times in 39 Posts
Thanked 11,046 Times in 4,352 Posts
JagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond reputeJagWaugh has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
I wouldn't do it though. It changes your

- engine to wheel gearing
- fuel economy (higher)
- speedo readings (higher)
- ABS sensors reading -> good luck
- Traction control sensor readings -> good luck

and it probably brings you closer to overloading your tyres smaller tyres carry smaller loads generally
Going down a single size is no problem.
It does make your speedo overread.
You'd be hard pressed to measure the fuel economy difference.
Your ABS compares the rotation of the 4 wheels to initiate ABS pulsing. The pulse rate may be based on the summer tires, but again, I doubt you'd manage to measure a difference.
Traction control, the better ones you change a setting so that the system adapts to the different size (but if you forget that, and go down 2 sizes and press the car it will indeed split arse all over the place).

Load rating is about sidewall strength, not diameter (and the speed and load rating of any tires need to be matched to the vehicle).

You could go for smaller width, as Tom suggests, but the general practice is to go down a size.
__________________
If everyone you know agrees with you consistently, they are either not listening, or not capable of critical thought.
Reply With Quote
  #7  
Old 20.10.2017, 16:28
Verbier's Avatar
Forum Legend
 
Join Date: Jul 2008
Location: Lully VD
Posts: 3,802
Groaned at 13 Times in 13 Posts
Thanked 3,800 Times in 1,952 Posts
Verbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond repute
Re: Smaller Winter Tyres for Van

This comment is normally made in the context of cars. If your summer tires are 17" and your drive wheels are in the front, you will see that there is little space between the tire and the wheel well. Specifically not enough space to slip on the chains in the winter (think at night, in the snow and with it snowing).

So, many people suggest in our hypothetical case to drop down to 16" winter tires so you leave more space to slip on the chains.

In the owner's manual of most cars they will give you the tire sizes that work together (in this case a version of the 17" and its corresponding 16" size).

In the case of a van (probably rear wheel drive) and if you have enough space to comfortably add chains, you many not "need" to drop down a size like in our car example above. However, have a look in the manual and you may see the option to do so.

The other avantage to smaller tires that some people appreciate is that they cost less.
__________________
Do or do not, there is no try(ing). Yoda
Reply With Quote
This user would like to thank Verbier for this useful post:
  #8  
Old 20.10.2017, 16:40
baboon's Avatar
Forum Legend
 
Join Date: Apr 2007
Location: Rheintal
Posts: 2,916
Groaned at 90 Times in 79 Posts
Thanked 3,816 Times in 1,875 Posts
baboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Maybe also worth mentioning that tyre sizes are specified by each car's type approval and you're not legally allowed to go outside that approved range unless you get approval from the MFK people (a friend who fitted 21" rims to a CX5 had to go that route).

No (reputable) Swiss garage or tyre fitter will knowingly supply illegal tyres as they're opening themselves up to problems with the law as well.
Reply With Quote
This user would like to thank baboon for this useful post:
  #9  
Old 20.10.2017, 16:44
Newbie 1st class
 
Join Date: Sep 2016
Location: Zurich
Posts: 23
Groaned at 0 Times in 0 Posts
Thanked 1 Time in 1 Post
Mountain High has no particular reputation at present
Re: Smaller Winter Tyres for Van

My current tyres are 225/75/16 and I was thinking of going down to 215/70/15. Does that seem about right?

Last edited by Mountain High; 20.10.2017 at 16:55.
Reply With Quote
  #10  
Old 20.10.2017, 16:46
baboon's Avatar
Forum Legend
 
Join Date: Apr 2007
Location: Rheintal
Posts: 2,916
Groaned at 90 Times in 79 Posts
Thanked 3,816 Times in 1,875 Posts
baboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
You could go for smaller width, as Tom suggests, but the general practice is to go down a size.
I would say the general practise is to go down a rim size, down a width size or even 2but up a profile size or even 2 (thus roughly maintaining total diameter).


So summer 17 x 235 x 55 might become winter 16 x 215 x 65 - slightly narrower, smaller (and cheaper) rim but pretty well same circumferance
Reply With Quote
This user would like to thank baboon for this useful post:
  #11  
Old 20.10.2017, 16:53
baboon's Avatar
Forum Legend
 
Join Date: Apr 2007
Location: Rheintal
Posts: 2,916
Groaned at 90 Times in 79 Posts
Thanked 3,816 Times in 1,875 Posts
baboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond reputebaboon has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
My current tyres are 225/75/16 and I was thinking of going down to 215/70/16. Does that seem about right?
No. Maintain at least the 75 section (this should rather go up than down but 75 is basically high enough!)
Reply With Quote
This user would like to thank baboon for this useful post:
  #12  
Old 20.10.2017, 16:55
Forum Legend
 
Join Date: Jun 2008
Location: Zurich
Posts: 5,543
Groaned at 185 Times in 144 Posts
Thanked 11,577 Times in 3,904 Posts
k_and_e has a reputation beyond reputek_and_e has a reputation beyond reputek_and_e has a reputation beyond reputek_and_e has a reputation beyond reputek_and_e has a reputation beyond reputek_and_e has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
I am about to buy a set of winter tyres for our Ducato based motorhome. I have heard that there is some advantage in going for a size smaller than your normal summer tyres but I don't really understand why. Can someone enlighten me!
first of all, check what is allowed on your car and specifically what is allowed on your rims
Reply With Quote
This user would like to thank k_and_e for this useful post:
  #13  
Old 20.10.2017, 16:59
Newbie 1st class
 
Join Date: Sep 2016
Location: Zurich
Posts: 23
Groaned at 0 Times in 0 Posts
Thanked 1 Time in 1 Post
Mountain High has no particular reputation at present
Re: Smaller Winter Tyres for Van

Thanks guys, lots of info here to consider!
Reply With Quote
  #14  
Old 20.10.2017, 17:21
st2lemans's Avatar
Forum Legend
 
Join Date: Dec 2010
Location: Lugano
Posts: 21,384
Groaned at 1,104 Times in 871 Posts
Thanked 24,097 Times in 11,527 Posts
st2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond reputest2lemans has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
No. Maintain at least the 75 section (this should rather go up than down but 75 is basically high enough!)
80 would be more correct (78.4 is ideal, but doesn't exist).

Tom
Reply With Quote
  #15  
Old 20.10.2017, 21:09
Verbier's Avatar
Forum Legend
 
Join Date: Jul 2008
Location: Lully VD
Posts: 3,802
Groaned at 13 Times in 13 Posts
Thanked 3,800 Times in 1,952 Posts
Verbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond reputeVerbier has a reputation beyond repute
Re: Smaller Winter Tyres for Van

Quote:
View Post
My current tyres are 225/75/16 and I was thinking of going down to 215/70/15. Does that seem about right?
There is NO guessing.

Have a look in the owner's manual and as others have said the LEGAL and authorised options in 16" and 15" will be shown. Don't go with anything else or in case of an accident you may not be 100% covered.

If you have 16" already and can get access to add chains, I would personally stay with 16". In 16" the Continental WinterContact TS 860 is highly rated.
Reply With Quote
Reply




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - 21" Porsche Alloy Wheels with Summer Tyres + Winter Tyres - Zug falexmap Items for sale 7 16.09.2015 13:05
[For Sale-ZH] Winter tyres 195/65 R15 Michelin Alpin - driven only one winter. zurichzoro Items for sale 3 04.12.2013 17:55
Winter Tyres for sale gian Items for sale 0 09.12.2012 15:17
Winter tyres or winter tyres and wheels mountainsandlakes Transportation/driving 23 22.10.2012 12:31
Winter Tyres/Summer Tyres- whats the difference ? simonminissale Transportation/driving 90 21.12.2010 10:43


All times are GMT +2. The time now is 17:08.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.1.0