Tyre temperatures
Recently, in this hot weather, I became concerned at the temperature rise of my motorhome tyres which increased from cold (15C) to as much as 32C. It actually triggered the alarm of my TPMS. Pressures also increase by about 10 to 12psi. If you have a TPMS, what is your experience and does anyone know what tyre termperatures are considered unsafe or put another way what is the safe operating temperature of typical road tyres?
peedee
Comments
-
See Here
I'm sure a bit more googling with more information will throw up actual figures for your particular brand and range of tyre.0 -
Both rises seem excessive. Usual reason would be under inflation but with TPMS you will be checking that. Is the base figure you have correct - see above post.
Have you had the vehicle from new? Could they be wrong tyres altogether?
0 -
Under inflation was my concern which is really why I posed the question. It seems from searching the net a 10C rise in temperature above ambient is not unusual after a half hours drive. Add in strong sunshinet and it can be much higher. Nevertheless it would be useful to read of the experience of others. Still not found anything about safe operating temperatures which would help in setting the alarm point. This brings me to another point. Tyres are marked with a max PSI. I presume this is a cold pressure?
peedee
0 -
My single axle caravan tyres running at 60psi cold (~25C) hit 60C and 69psi -72psi at motorway speeds in a UK summer as monitored by my Tyrepal with internal sensors.
My towcar psi increases by 3- 6 but I guess that is because each tyres loaded with 300Kg rather than 750Kg on the van
1 -
-
Already weighed it and used the handbook figures for the pressures for the actual weight. It would appear high temperatures are nothing unusual. I have certainly not seen anything like the temperature increases what Viatorem quotes although I regularly see increases in PSI of 10 from cold.
One article I have seen says that tyres should be inflated for the MTPLM given that most motorhomes run fully laden which is probably why if you consult Michelin they give a figure of 80psi for their camper tyres.
peedee
0 -
My Tyrepal TPMS is set to display PSI not temperature. The rears that start off at 80 psi will go up to 94 psi on a long run. The fronts will go from 55 to 65. When setting up the system I followed their guidelines, The alarm did go off once in Germany which I never quite got to the bottom of.
David
0 -
Temperature rise in tyres can have a dramatic effect ! I know because I suffered a somewhat dramatic explosion in a tyre some years ago when descending from the Pyrenees on a very hot day!
We had been staying on a site Nr Lourdes for a couple of days and it was time to cross the pyrenees en route to Perpignon . So I checked & preppt the van for the long journey making sure that the tyres were at the correct pressure. I can't now remember what that was, but it was a fairly high pressure on my 2003 Avondale Osprey.
We set off fairly enthusiastically, as the route although steep in places caused no problem to my then 3 litre Toyota Landcruiser. We stopped for a picnic Nr the topmost part of the route, before setting off for Perpignone on the Med coast. By now the outside air temp had climbed to 36 degrees C but we were nice & cool in the air con cabin.
I was conscious of the need to preserve my brakes, and so was using the manual selection facility on the automatic gearbox to use engine braking wherever possible, in order to keep my brakes cool.
But 2/3rds of the way down, on a sweeping right hand bend I was travelling at about 55 mph, when there was an enormous explosion, and it felt like the car and caravan were traveling over a rough washboard surface. I looked in my nearside mirror and to my horror, all I could see were smoke and flames billowing out of my caravans nearside wheel arch. I was giving a good impression of Concorde's fatal take off from Paris!
Luckily I was able to bring the rig to a smooth halt in a convenient lay by, and examined the damage! I had fitted Tyron bands to the caravan wheels, and they seemed to have done a good job, for the tyre had remained on the wheel, but the tyre itself was completely shredded, there could be no possibility of repair! It was far too hot to touch for some time, - and so was the still intact offside wheel but that was dangerously hot too!
I had been so intent on keeping my Land cruisers brakes cool on the long descent that I had completely forgotten that using Engine braking on the car didn't relieve the overrun brakes on the Caravan. An outside air temperature now exceeding the earlier 36 degrees did the rest!
So yes! Do watch out for your van tyre temperatures in this weather! When they blow its like a bomb going off!
TF
0 -
Our caravan has Tyrepal sensors, on a run from cold we gain 10 psi and the temperature always rises by 25 deg C above the ambient temperature.
0
