How to set the correct tyre pressure in freezing temps?
Discussion
Apart from obviously with gloves on as its bloody cold out there, how should tyre pressures be set when it's freezing (i.e. way below 'cold' or 'ambient' temperature outside) - still follow the pressures recommended inside the fuel filler flap, inflate using a few more psi to compensate for the cold outside temperature so that they're just right once warmer, or otherwise?
Just to clarify, I want the pressures to be 'as normal' when up to warm road temperatures, but have got new tyres and tyre places never seem to set them correctly.
Just to clarify, I want the pressures to be 'as normal' when up to warm road temperatures, but have got new tyres and tyre places never seem to set them correctly.
I put one of those tyresure monitoring devices on the car so get real time temp/press from all 4 wheels.
In -6deg C, with the tyres set at a proper, cold 34psi I started my normal Monday commute of 125 miles. During that whole run the tyre temps hit 11degC max and pressures approx 37psi maximum. They're 275/50 17's.
So, I'd say just set them cold!
In -6deg C, with the tyres set at a proper, cold 34psi I started my normal Monday commute of 125 miles. During that whole run the tyre temps hit 11degC max and pressures approx 37psi maximum. They're 275/50 17's.
So, I'd say just set them cold!
thiscocks said:
Ive never compensated for weather!
Me neither but then again I've never had to face temps of -15C outside at 6am according to the dash! I was just curious if such abnormally low temperatures we're getting this year means adjusting slightly when checking pressures.As mentioned I guess a good way to do it is set them as normal when cold then check again when hot after a long commute.
5lab said:
low tyre pressures are good for grip in icy\snowey conditions, and would automatically compensate when the weather warms up. nice
Can you prove that? Seriously. Coz I reckon the tread would fold in on itself closing the tread pattern grooves and producing less grip...Winter tyres get inflated to 2-3 psi above normal.
doogz said:
jshell said:
5lab said:
low tyre pressures are good for grip in icy\snowey conditions, and would automatically compensate when the weather warms up. nice
Can you prove that? Seriously. Coz I reckon the tread would fold in on itself closing the tread pattern grooves and producing less grip...Winter tyres get inflated to 2-3 psi above normal.
What sort of tyres so you buy? BMX ones?
doogz said:
jshell said:
doogz said:
jshell said:
5lab said:
low tyre pressures are good for grip in icy\snowey conditions, and would automatically compensate when the weather warms up. nice
Can you prove that? Seriously. Coz I reckon the tread would fold in on itself closing the tread pattern grooves and producing less grip...Winter tyres get inflated to 2-3 psi above normal.
What sort of tyres so you buy? BMX ones?
Blowing them up isn't really going to increase the pressure they exert on the surface, in the way that fitting narrower tyres would, not by any real amount, and it's just going to make them less complaint.
jshell said:
doogz said:
jshell said:
doogz said:
jshell said:
5lab said:
low tyre pressures are good for grip in icy\snowey conditions, and would automatically compensate when the weather warms up. nice
Can you prove that? Seriously. Coz I reckon the tread would fold in on itself closing the tread pattern grooves and producing less grip...Winter tyres get inflated to 2-3 psi above normal.
What sort of tyres so you buy? BMX ones?
Blowing them up isn't really going to increase the pressure they exert on the surface, in the way that fitting narrower tyres would, not by any real amount, and it's just going to make them less complaint.
to me it sounds counter productive when people say put weight in the boot (rwd, obviously) to increase pressure on the driven contact patches, then let the tyres down, thus increasing the contact patch and reducing the pressure applied over it
Edited by dylan0451 on Tuesday 21st December 15:18
Tyre pressures should always be kept up for driving on snow, to allow the tyre tread to cut into the snowy surface, rather than slithering around on top of it. It also helps the snow and ice to clear out of the tread as the tyre rotates. Lowering the pressure just allows the tread to 'squash' the snow into itself more.
Same reason why big, wide tyres are in general rubbish in snow, and skinny tyres are, in general, pretty good.
My Saab 900 on 185/65 tyres is definitely more surefooted in the cold stuff than the 9-3, which has 215/45s, although both are OK.
Same reason why big, wide tyres are in general rubbish in snow, and skinny tyres are, in general, pretty good.
My Saab 900 on 185/65 tyres is definitely more surefooted in the cold stuff than the 9-3, which has 215/45s, although both are OK.
doogz said:
How much wider do you think the tyre gets by letting it down a bit?
Why do you not want it to be fully in contact with the ground? Do you not want it to grip?
i'd imagine that the actual pressure, and deformation of the carcass under the cars weight is different to the overall contact patch and weight distribution on the tread of that patch to the ground. i'm guessing, again, that the softness of the compound already creates a larger contact patch, and that the design and shape of the blocks is designed around a target working psi with some tolerance.Why do you not want it to be fully in contact with the ground? Do you not want it to grip?
course, that could be b
ks as the tyre manufacturer has to factor in some kind of idiot proofness, and the consideration the tyre may be run at high speed for a long duration, hence not mentioning that their product may work at it's best at lower pressures.maybe we should do a practical. unfortunatly it's all so subjective...
V88Dicky said:
I don't worry at all. When I checked my tyres in September they were at 32psi, exactly where they should have been. A few weeks of freezing weather shouldn't make much difference 
True, but they're 2 new rear tyres and no surprise when I checked them the tyre fitters had inflated one to 29psi and the other 35psi, so I wasn't going to leave them as they were!The recommended for my car is 33 for unladen, 36 for fully laden, so I'm going with the lower figure as it's snowy/icy, and the reading may be misleadingly (sp?) low as it's fecking freezing outside! I'm sure for a few weeks it doesn't matter THAT much if it's out a little, but I at least like them to match across each axle
yellowbentines said:
True, but they're 2 new rear tyres and no surprise when I checked them the tyre fitters had inflated one to 29psi and the other 35psi, so I wasn't going to leave them as they were!
We got a van back from the tyre fitters, had stickers above the wheels saying "35psi"... yet they still managed to inflate one of them to 10 and the other to 65! Thought it was tracking to one side lol...Edited by Camaro91 on Tuesday 21st December 20:12
How about this:
At -10C 33 psi is still 33 psi.
Only when temps are back to 20 degrees would that same quantity of air actually exert more pressure.
And when running about at -10 your tyres aren't going to warm up to the same operating temperature as a 20 degree summer's day. So it's probably negligible.
... And if you were up in the alps at -10 and you drove down to a French valley at 20 degrees people's tyres don't seem to be exploding all over the shop.
At -10C 33 psi is still 33 psi.
Only when temps are back to 20 degrees would that same quantity of air actually exert more pressure.
And when running about at -10 your tyres aren't going to warm up to the same operating temperature as a 20 degree summer's day. So it's probably negligible.
... And if you were up in the alps at -10 and you drove down to a French valley at 20 degrees people's tyres don't seem to be exploding all over the shop.
Gassing Station | General Gassing [Archive] | Top of Page | What's New | My Stuff