Winter Tyre pressures
Discussion
ok so the crappy dunlop website provides no info on tyre pressures. So refer to vehicle manufacturer. For my Nissan the manual does not state any tyre pressures at all it says to refer to the sticker on the B pillar. That provides tyre pressures (in my case 34 front / 31 rear) but with no special reference to winter tyres. The manual states Nissan may fit winter tyres to some vehicles, but not which ones / or when.
So, there is no reference / advice anywhere as to whether or not different tyre pressures should be used. So probably leave standard then, but anyway: Any ideas? For some of you where there is advice in the manual re tyre pressures for winter tyres, can you tell me what it says please? Then I will make my own decision. ie 'normal' tyres may be 31 psi, and with winter tyres it may say 35 psi - then I know that some manufacturers are increasing pressures with winter tyres (or not). (3D DUNLOP SP WINTER SPORT in my case)
just want to keep this specific to winter tyre pressures, nothing else, thanks.
So, there is no reference / advice anywhere as to whether or not different tyre pressures should be used. So probably leave standard then, but anyway: Any ideas? For some of you where there is advice in the manual re tyre pressures for winter tyres, can you tell me what it says please? Then I will make my own decision. ie 'normal' tyres may be 31 psi, and with winter tyres it may say 35 psi - then I know that some manufacturers are increasing pressures with winter tyres (or not). (3D DUNLOP SP WINTER SPORT in my case)
just want to keep this specific to winter tyre pressures, nothing else, thanks.
CoolHands, your car weighs the same in winter as it does in summer, yes? Therefore, the tyre pressures are the same as on summer rubber 
For example, look what the snow driving pros use;
P_J_R said:
I tend to run my winter tyres about 2psi lower than normal so more footprint on the road. HTH
Unless you are driving in deep (and I mean really deep) powder, you are doing yourself no favours. Narrower tyres tend to work better in more snow related situations than wider ones.For example, look what the snow driving pros use;
Codswallop said:
CoolHands, your car weighs the same in winter as it does in summer
yeah but I didn't know if it's meant to be higher pressure to help maintain the tyre pattern. Since my manual makes no reference to it I don't know what is standard or common practice amongst all manufacturers. Codswallop said:
Unless you are driving in deep (and I mean really deep) powder, you are doing yourself no favours. Narrower tyres tend to work better in more snow related situations than wider ones.
For example, look what the snow driving pros use;
I don't disagree with your point, but dropping the tyre pressure lengthens the contact patch rather than widening it.For example, look what the snow driving pros use;
[/pedant]
Bill said:
I don't disagree with your point, but dropping the tyre pressure lengthens the contact patch rather than widening it.
There's two opposing theories so take your choice. First is what you say, lower the pressure and get the tread blocks moving more thus more heat and grip plus more contact area, the other is to raise the pressure to open the tread blocks out or keep them firmer so they grip better in snow or move water better in the rain. CoolHands said:
yeah but I didn't know if it's meant to be higher pressure to help maintain the tyre pattern. Since my manual makes no reference to it I don't know what is standard or common practice amongst all manufacturers.
Most manufacturers (whose handbooks i have seen) recommend same pressures for winters and summers.On the Audi, Summer tyres are 275/30 20" and Winter tyres are 235/40 19" (not a particularly convenient arrangement!) According to the sticker on the driver's door, both to be inflated to the 2.8(41) Front; and 2.4(35) Rear. No mention in the Handbook about what ambient temperature should be for these pressures but for summer it is usually 20C.
As winter tyres are recommended for use when temperatures fall below 7C you might have thought that would be the appropriate ambient temperature for setting pressures, but there is no mention.
To go slightly off topic, the car is FWD and the handbook says chains to go on front wheels. On another FWD car I have the handbook says chains to go on rear. Confusing.
As winter tyres are recommended for use when temperatures fall below 7C you might have thought that would be the appropriate ambient temperature for setting pressures, but there is no mention.
To go slightly off topic, the car is FWD and the handbook says chains to go on front wheels. On another FWD car I have the handbook says chains to go on rear. Confusing.
lowndes said:
As winter tyres are recommended for use when temperatures fall below 7C you might have thought that would be the appropriate ambient temperature for setting pressures, but there is no mention.
Pressure is dependent on temperature (which is why you check when the tyres are cold) so whatever the current temperature is is the correct ambient. IYSWIM.Bill said:
Pressure is dependent on temperature (which is why you check when the tyres are cold) so whatever the current temperature is is the correct ambient. IYSWIM.
I think that makes sense. On cars with TPM I see a pressure rise of up to 0.3bar as the tyres heat up from normal day to day driving, though filling with nitrogen can help reduce this fluctuation. Whether the manufacturers take this into account when specifying tyres pressures I am not sure. They sometimes use the term "setting the pressures when cold" to mean do it when the vehicle has been stationary for a while. lowndes said:
I think that makes sense. On cars with TPM I see a pressure rise of up to 0.3bar as the tyres heat up from normal day to day driving, though filling with nitrogen can help reduce this fluctuation. Whether the manufacturers take this into account when specifying tyres pressures I am not sure. They sometimes use the term "setting the pressures when cold" to mean do it when the vehicle has been stationary for a while.
Driving heats up tyres so setting them cold is when they've not been used. Gassing Station | General Gassing | Top of Page | What's New | My Stuff