An interesting observation; but kind of expected behavour.

 

I've purchased some winter tyres for my Octy Scout - and have enabled Winter Tyres mode on the MIB system.  All is good.  Speed warning works just fine.

 

However, once every week or so, I perform the obliguitory Emergency brake test.  On normal tyres, the car brakes nice and straight and the hazzards flash away....all is good with the world.

 

With my Winter Tyres on and with Winter Tyres enabled on the car, the car is now brakes very differently.  ABS is a lot less effective and I cannot (under any circumstances) - get the hazards to flash....they refuse to do it.

I am assuming that the braking profile changes and this means that the car acts differently, but I didn't know whether this was expected behavour or not.

 

Many thanks

 

 

 

(chilly from Scotland)

The Winter Tyre Mode just allows you to set the speed at which the warning that winter tyres are fitted so that is not changing anything in the braking system.

 

Without the ABS acting is the braking is happening OK without the car skidding / wheels locking up?

?

If you go someplace safe and wide and brake hard can you steer as you might need to in an emergency?

The flashing lights I believe come on when the retardation exceeds a certain threshold, perhaps the winter tyres under current temperatures dont have as much braking grip & the ABS is modulating to avoid wheel lock, less effective braking and no flashing lights?

 

I fitted my winter wheels & tyres yesterday (first time ever) and did not think to check the braking, I'm not looking to push the envelope so the braking & cornering will be what they will be, with luck and reading the road ahead I will never find the limits.

 

I have a related question, I knew that I had to reset the TPMS but was and still am too lazy to serch through the manual, I pressed the button, then decided to press & hold it, it then beeped, I tried again to be sure & then just drove normally, no warnings lights or anything but have I actually reset it to the new wheels?

 

The tyre size is the same in any case although they look bigger, probably the black steel rims.

@J.R.you've acknowledged a new set of tyre pressures - but are they the correct ones?

Edited 23 November, 20205 yr by john999boy
Typo

They were close enough until the weather is better, I did check them, 2.0 bar with one at 1.9 bar, sticker says 2.2 bar, good enough for now.

 

Not sure if I have actually acknowledged what is presumably the (re)learning process as I read that I should have turned off the ignition.

 

Mine is the indirect TPMS, I should have indicated that.

42 minutes ago, varaderoguy said:

 

I've purchased some winter tyres for my Octy Scout - and have enabled Winter Tyres mode on the MIB system.  All is good.  Speed warning works just fine.

 

 

You say winter tyres but don't say the manufacturer.  Not all winter tyres are created equal,  If you've fitted budget ones you may well not have anything approaching the levels of grip that you had with your previous tyres.

 

Also, why enable the Winter Tyre mode?  My understanding has always been that it's only there as a warning not to exceed the maximum speed of the tyre and is a requirement in certain countries in Europe.  You're probably unlikely to be exceeding

100 mph during the winter in the Borders.  

1 minute ago, Schtum said:

 

You say winter tyres but don't say the manufacturer.  Not all winter tyres are created equal,  If you've fitted budget ones you may well not have anything approaching the levels of grip that you had with your previous tyres.

 

Also, why enable the Winter Tyre mode?  My understanding has always been that it's only there as a warning not to exceed the maximum speed of the tyre and is a requirement in certain countries in Europe.  You're probably unlikely to be exceeding

100 mph during the winter in the Borders.  

Good call - and thanks for asking.

 

I am on a set of brand new (they've been on the car for 600 miles) of Pirelli Winter SottoZero 3 tyres.

 

I do have Winter Tyre mode enabled....I promise I won't break the speed limit in the Borders!

It is handy having 2 max speed limits set.

I use the Winter Tyre one for my 'over the 70mph limit and might get 3 points and £100 fine, as i have only to get 3 more for a ban.

Then the other setting i use as the warning of you are sure to get a ban even if you go to court and say Employees depend on you and you raise millions for charity.

5 minutes ago, varaderoguy said:

Good call - and thanks for asking.

 

I am on a set of brand new (they've been on the car for 600 miles) of Pirelli Winter SottoZero 3 tyres.

 

I do have Winter Tyre mode enabled....I promise I won't break the speed limit in the Borders!

 

I had a set of those on 17" Audi alloys on my wife's previous 16 plate Tiguan 184 TDI.  I didn't like them and they didn't wear well.  After they wore out, I replaced them with Dunlop Winter Sport D5.  I've also previously used the D4 version and have always found them

to be excellent in snow and on icy roads.  I even ran a 16" set through a whole year once on an earlier Tiguan and they were preferable to the original 19" rubber.

 

Good place to break the speed limit.  I regularly see three figures on certain bits of deserted road, especially when I'm on the bike.  Whereabouts are you? 

Taken from the Manual - it doesn't mention any changes to the braking profile, so maybe this is a tyre issue:

 

Speed symbolAll-season or “winter” tyres (marked with M+S and a peak/snowflake symbol) of a lower speed category than stated in the technical vehicle documenta-tion can be used, provided the permissible maximum speed of these tyres isnot exceeded even if the possible maximum speed of the vehicle is higher.The speed limit for all-season or “winter” tyres can be set in the infotainmentsystem in menu /  →  → Tyres.If the vehicle has all-season or “winter” tires of a lower speed category thanthe specified maximum speed of the vehicle (referring to tyres that have notbeen delivered by the factory), then a warning label with the maximum value ofthe speed category provided for the fitted tyres must be fixed in the interior ofthe vehicle in a constantly visible place in the driver’s field of vision. The warn-ing label (sticker) can be replaced by setting the maximum value of the speedcategory specified for the mounted tyres in Infotainment (only applies to cer-tain countries). This specification defines the maximum vehicle speed withmounted all-season or “winter”tyres that may not be exceeded.

Edited 23 November, 20205 yr by varaderoguy

As said all the winter tyres setting does is allow you to set a speed warning as winter tyres normally have a much lower max speed than the original summer tyres. It certainly doesn’t change any braking profiles or anything else.

There is one road when you turn off the main road @ the Borders that i love to take a 'demonstrator' to where you can try up and down and clearly see that there are no police or camera vans about on.

Ooohhh....thats the Selkirk to Moffet road by the SB boundary with Dumfries and Galloway near St Marys Loch. Lovely.

1 hour ago, varaderoguy said:

Taken from the Manual - it doesn't mention any changes to the braking profile, so maybe this is a tyre issue:

 

Speed symbolAll-season or “winter” tyres (marked with M+S and a peak/snowflake symbol) of a lower speed category than stated in the technical vehicle documenta-tion can be used, provided the permissible maximum speed of these tyres isnot exceeded even if the possible maximum speed of the vehicle is higher.The speed limit for all-season or “winter” tyres can be set in the infotainmentsystem in menu /  →  → Tyres.If the vehicle has all-season or “winter” tires of a lower speed category thanthe specified maximum speed of the vehicle (referring to tyres that have notbeen delivered by the factory), then a warning label with the maximum value ofthe speed category provided for the fitted tyres must be fixed in the interior ofthe vehicle in a constantly visible place in the driver’s field of vision. The warn-ing label (sticker) can be replaced by setting the maximum value of the speedcategory specified for the mounted tyres in Infotainment (only applies to cer-tain countries). This specification defines the maximum vehicle speed withmounted all-season or “winter”tyres that may not be exceeded.

 

The only thing to change the braking profile is the 'off road' mode - When on, up to speeds off about 25mph the system allows the wheels to lock up a little longer when hitting the brakes and is designed to form a wedge of snow/mud/leaves etc in front of the wheels to aid braking.  Additionally you get the hill decent control and the hill climbing 'thing' that from memory makes the throttle less responsive / allows you to climb gradients less aggressivley.

Flashing brakelights / hazards are as of 7m/s^2 deceleration if I remember correctly. You might not be able to achieve this with winter tyres. 

 

Dry, cold road? maybe. Damp, cold? I doubt it very much. 

 

To be honest, I'd take an inflatable something-or-other out and try to brake from 30mph to stop as close to the object as possible. It's good practice and harder than it seems. Teddy might also work. That would give you a good feel for just how hard you need to / can push the brake pedal to get ABS to kick in. Remember the rubber is a lot softer on the winters and so it may well squidge more before triggering ABS. 

 

 - Bret

4 hours ago, varaderoguy said:

Good call - and thanks for asking.

 

I am on a set of brand new (they've been on the car for 600 miles) of Pirelli Winter SottoZero 3 tyres.

 

I do have Winter Tyre mode enabled....I promise I won't break the speed limit in the Borders!

So good quality winter tyres.

 

Possibly if they were brand new when you did the test, they still had some coating (a releasing agent from tyre mould), it scrubs off after few days of use, and this lowered the braking speed

 

Which (summer or winter) tyres are most grippy will depend on temperature, how damp/wet vs dry, and the surface (and tarmac comes in many grades)

 

 

For good braking the tyre needs continuous band/bands of rubber tread all around the circumference.

 

Tyres that are winter, TPMSS marked, All Season or M + S marked will not have this.

 

Look here for more information:- 

 

 

Thanks, AG Falco