I have fitted some winter Wheels and Tyres to the Wife's Fabia MkII Vrs (205/45/16)

Are they the same Psi as Summer tyres (Ooopps sorry wrong forum)

Holds head in shame

Genuine Mistake..................Honest

If this is a genuine question then no, you need to add an extra 0.2 bar.

Depends on tyre to some extent. My winters run best with an extra 10psi (0.7 bar).

I'd say, in general, stick with what the car manufacturer suggests for that size of tyre on that car, any premium tyre sellers/fitters that I've dealt with have given that advice.

If this is a genuine question then no, you need to add an extra 0.2 bar.

Depends on tyre to some extent. My winters run best with an extra 10psi (0.7 bar).

I'd say, in general, stick with what the car manufacturer suggests for that size of tyre on that car, any premium tyre sellers/fitters that I've dealt with have given that advice.

this is new to me, but my dealer seems to agree, they fitted my winters, and when chasing the time the service manager said "he's just setting up your tyre pressures, then he's done.." and on checking they have upped the pressure by 0.5 bar on all four wheels....

anyone explain the reasoning behind this?

edit: I've left them at what he set them at...

Winter tyres are made from (more?) silica than summer tyres, this is what stops them going hard below 7°c, this is the reason for the increase in pressures.

Look in the cars handbook and it will tell you to add 0.2bar to winter tyres

As we all know air expands with heat..........so as the tyre is used and gets warm the air inside warms up and expands so the internal pressure is now higher! Conversley as the the tyre cools the air in side contracts and thus the pressure lowers...........this happens with either the internal air temp or the external air temp!!!

From memory most of the manufactures tyre pressures (on the fuel filler cap) are quoted at 20C.......but there is roughly a 0.1bar pressure drop per 10C drop.....Proper calcs below!!

+20C = 68F say your cold tyre pressure is 2.1bar = 30.46psi

+10C = 50F now your tyre pressure is 1.98bar = 28.66psi

0C = 32F now your tyre pressure is 1.85bar = 26.86psi

-10C = 14F now your tyre pressure is 1.73bar = 25.06psi

-20C = -4F now your tyre pressure is 1.60bar = 23.26psi

I tend to lower the tyre pressure from the manufactures stated figure by 0.1bar per 10C drop.....but only realy start altering the pressures when the outside temps and the tyres are at a steady 0C! So at 0c I do not inflate my tyre to 2.1bar but to 1.9bar...this means that as the tyre heats up it will not be "over pressure" at the same hot temp as if I inflated the tyre to 2.1bar at 20C....

If I inflate the cold 0C tyre to 2.1bar (pressure for 20C) then when the air in the tyre gets to 40C the pressure will be 2.5bar!........If the tyre is at 2.1bar @20C as per the fuel filler cap then at 40C it will be 2.3bar........so a diff of 0.2bar!!!!!

These are my personal choices re tyre pressure.........most experts state don't mess with the tyre pressures to much (0.3bar at most from the manufactures).....it is very subjective as it affects feel and can alter from one tyre to the next!

P.S. I think that Skoda state + 0.2bar to their normal tyre pressures......but again note above comment^!

Edited 17 November, 201114 yr by fabdavrav

i hate that i have winter tyres fitted now and it's been 15-16 degrees everyday since.

Now everyone knows about winter tyres, and even advertising them on TV, we're going to have the hottest winter in recorded memory ...

As we all know air expands with heat..........so as the tyre is used and gets warm the air inside warms up and expands so the internal pressure is now higher! Conversley as the the tyre cools the air in side contracts and thus the pressure lowers...........this happens with either the internal air temp or the external air temp!!!

From memory most of the manufactures tyre pressures (on the fuel filler cap) are quoted at 20C.......but there is roughly a 0.1bar pressure drop per 10C drop.....Proper calcs below!!

+20C = 68F say your cold tyre pressure is 2.1bar = 30.46psi

+10C = 50F now your tyre pressure is 1.98bar = 28.66psi

0C = 32F now your tyre pressure is 1.85bar = 26.86psi

-10C = 14F now your tyre pressure is 1.73bar = 25.06psi

-20C = -4F now your tyre pressure is 1.60bar = 23.26psi

I tend to lower the tyre pressure from the manufactures stated figure by 0.1bar per 10C drop.....but only realy start altering the pressures when the outside temps and the tyres are at a steady 0C! So at 0c I do not inflate my tyre to 2.1bar but to 1.9bar...this means that as the tyre heats up it will not be "over pressure" at the same hot temp as if I inflated the tyre to 2.1bar at 20C....

If I inflate the cold 0C tyre to 2.1bar (pressure for 20C) then when the air in the tyre gets to 40C the pressure will be 2.5bar!........If the tyre is at 2.1bar @20C as per the fuel filler cap then at 40C it will be 2.3bar........so a diff of 0.2bar!!!!!

These are my personal choices re tyre pressure.........most experts state don't mess with the tyre pressures to much (0.3bar at most from the manufactures).....it is very subjective as it affects feel and can alter from one tyre to the next!

I'm really glad I asked now

I'm really glad I asked now

If I get into the swing of it and my brains properly working......I CAN MAKE YOUR HEAD HURT..

If I get into the swing of it and my brains properly working......I CAN MAKE YOUR HEAD HURT..

MMmmmmmm.........I could do with you speaking to the wife about my Marital Ban

i hate that i have winter tyres fitted now and it's been 15-16 degrees everyday since.

Ditto. Forked out for 2 sets of winter tyres, and it's been really mild, and warmer than in the summer.

gonna be zero here tonight, and -2 tomorow night... was frost on the car last night... they say in 2 weeks the real cold is coming... rained like hell yesterday, and my god are they good at cutting water!

and thanks for the explanations, I do of course know about how much pressure is lost in cold wether... just never occured to me! lol... but if when he fitted them (16c day) in the nice warm garage, and added 0.5 bar compaired to normal pressures, I will be glad he did when I'm driving in -16.9 again this winter! lol...

but if when he fitted them (16c day) in the nice warm garage, and added 0.5 bar compaired to normal pressures, I will be glad he did when I'm driving in -16.9 again this winter! lol...

I'd let some air out if they've added 0.5bar ontop of the standard Skoda setting!!......even in my calcs the most is 0.4bar diff...and you really shouldn't mess more that + or - 0.3bar......even Gizmo68 says that the Skoda handbook states 0.2bar!!!........

I'd let some air out if they've added 0.5bar ontop of the standard Skoda setting!!......even in my calcs the most is 0.4bar diff...and you really shouldn't mess more that + or - 0.3bar......even Gizmo68 says that the Skoda handbook states 0.2bar!!!........

I'll check 'em on the next cold morning

I used to run a garage/tyre shop in Poland and there temps get down to -30, in the winter we generally pumped about 2 psi into 14 or 15 inch tyres, a bit less for smaller ones. 16s or 17s were at 2.1/2.2. As someone quite rightly mentioned, the pressure increases as the air in the tyre warms up, and also you do get better low speed grip on snow at those lower pressures.