Tyre temperature in Winter
Discussion
It was 3 degrees when I left home on Monday morning. I wishes that I had winter tyres on my car then.
However, after about 30 minutes driving I noticed that the dash was showing that the tyre temperatures were all around 20°C.
I Understand the winter tyres come into their own below about 7°, but what happens when the summer tyres get up to 20°C? Are winters is still more effective at this point or are the summer tyres operating better than winter tyres because of the temperature of the rubber is 20°?
However, after about 30 minutes driving I noticed that the dash was showing that the tyre temperatures were all around 20°C.
I Understand the winter tyres come into their own below about 7°, but what happens when the summer tyres get up to 20°C? Are winters is still more effective at this point or are the summer tyres operating better than winter tyres because of the temperature of the rubber is 20°?
Worry about the road surface temp, not the tyre temp.
Untrafficked roads will easily be 3-5degC colder than air temp, esp overnight, because the surface loses heat by radiation to the cold night sky (/radiant/ temp, c -60degC equiv at Earths surface; and, very clear nights go with low humidity in cold weather)
First out in the morning, tyres at 10-20degC; air temp at 3deg - it is entirely possible, in fact, very very likely, to subsequently hit frost or ice locally on the road surface, 0 to -4C; maybe lower across the bottom of a hill/ valley, where the cold air has pooled downhill overnight: 5miles north of Bath parallel with the A46 is 'Freezing Hill lane' ; name derived from hundreds of years of observation .. and ..it often bloody well is from these factors! I took a BMW sledging there, once ..
tl;dr: Tyre temperature has /nothing/ to do with traction at such times. Take care!
Untrafficked roads will easily be 3-5degC colder than air temp, esp overnight, because the surface loses heat by radiation to the cold night sky (/radiant/ temp, c -60degC equiv at Earths surface; and, very clear nights go with low humidity in cold weather)
First out in the morning, tyres at 10-20degC; air temp at 3deg - it is entirely possible, in fact, very very likely, to subsequently hit frost or ice locally on the road surface, 0 to -4C; maybe lower across the bottom of a hill/ valley, where the cold air has pooled downhill overnight: 5miles north of Bath parallel with the A46 is 'Freezing Hill lane' ; name derived from hundreds of years of observation .. and ..it often bloody well is from these factors! I took a BMW sledging there, once ..
tl;dr: Tyre temperature has /nothing/ to do with traction at such times. Take care!
Edited by Huff on Wednesday 10th January 21:04
its the outside of the tyre temp that matters, your car is probably telling you the air temp inside the tyre, as a prototype engineere we measure the air temp i the tyre and the outside tyre temp in 3 places out, middle, inner, very usefull info and also tyre pressure, but this is used more for detecting punctures, but is usefull for set up etc
It’s road surface condition that matters. Heresy to say it on PH, but that is more important than outside temperature. As for tyre temperature, I’m not sure that adds more information than tyre pressure.
I did note that my TPMS threw up a low pressure caution when the temperature dropped - all tyre pressures had dropped from the original setting a few months ago. I think a fall of 3 psi is the trigger point. So I got some exercise with my cycle track pump and put the pressures up all round and reset.
I did note that my TPMS threw up a low pressure caution when the temperature dropped - all tyre pressures had dropped from the original setting a few months ago. I think a fall of 3 psi is the trigger point. So I got some exercise with my cycle track pump and put the pressures up all round and reset.
belfry said:
It was 3 degrees when I left home on Monday morning. I wishes that I had winter tyres on my car then.
However, after about 30 minutes driving I noticed that the dash was showing that the tyre temperatures were all around 20°C.
I Understand the winter tyres come into their own below about 7°, but what happens when the summer tyres get up to 20°C? Are winters is still more effective at this point or are the summer tyres operating better than winter tyres because of the temperature of the rubber is 20°?
Could it have been 2.0 bar pressure that was showing and not temperature at all?However, after about 30 minutes driving I noticed that the dash was showing that the tyre temperatures were all around 20°C.
I Understand the winter tyres come into their own below about 7°, but what happens when the summer tyres get up to 20°C? Are winters is still more effective at this point or are the summer tyres operating better than winter tyres because of the temperature of the rubber is 20°?
Because I tow a heavy trailer and have had trailer blowouts, I fitted an after market kit to the trailer wheels and (why not?) the Transit itself. The sensors are alternative valve caps, and the dash readout shows pressure and temperature. Although the sensors are out in the airflow, they do show tyre heat reliably. This has shown a defect - a piece of metal in a side wall - by showing a heat increase before the pressure stated to fall. This allowed me to get off the motorway and change my wheel in a much safer situation.
I wouldn't be without them!
John
I wouldn't be without them!
John
tapkaJohnD said:
Because I tow a heavy trailer and have had trailer blowouts, I fitted an after market kit to the trailer wheels and (why not?) the Transit itself. The sensors are alternative valve caps, and the dash readout shows pressure and temperature. Although the sensors are out in the airflow, they do show tyre heat reliably. This has shown a defect - a piece of metal in a side wall - by showing a heat increase before the pressure stated to fall. This allowed me to get off the motorway and change my wheel in a much safer situation.
I wouldn't be without them!
John
Now that's an accessorywell worth having, any chance of a link to where you found that set that genuinely works please.I wouldn't be without them!
John
Presumably the new valve caps must have some sort of power supply inbuilt to transmit the signal? replaceable batteries?
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