What tire pressure do you run on winter/snow tires?
12-10-2016, 08:41 PM
#1
What tire pressure do you run on winter/snow tires?
Mine after being in storage are at about 25 psi cold. I don't remember if these were higher before but I want to say I should air these up to about 30 or 35. They're skinnier, taller tires at I think 215/65/R17.
12-12-2016, 07:33 AM
#5
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Proper inflation pressure is a function of the load vs inflation tables, and a larger tire does not need to be inflated quite as much. Conversely, a slightly smaller tire can sometimes be "crutched" up to meet your car's load requirements with a little more than door plate pressure.
Larger here means Load Index number and whether the tire is designated Standard Load, eXtra Load, or some other description (Light Load, P-metric, maybe more). There is an official procedure for adjusting pressures to suit different size tires, buried in the text that accompanies the load vs inflation pressure tables.
I have a copy of the SL and XL tables and some of the P-metric information . . . and a little home-grown spreadsheet app to do exactly the sort of pressure adjustment you need for size changes involving the SL and XL tables.
FWIW, I do set the same pressures year round for my street driving, but they differ a little from the sticker number for handling behavior that's a little less understeerish. The track driving gets still different pressures (and are measured hot instead of cold).
Norm
Last edited by Norm Peterson; 12-12-2016 at 07:40 AM.
12-12-2016, 07:48 AM
#6
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Norm
12-12-2016, 08:53 AM
#7
IN JAIL!
Join Date: May 2016
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I run my tires at just slightly less pressure in the winter, I have no science behind this other than as the air gets colder the tires lose a little pressure then when it warms up, the pressure comes back. and this way i don't need to adjust pressure. it's just automatically ok all year. it's kinda like not washing my car. I just make sure there's enough pressure to avoid overnight flatspots. the other advantage of this is, when your tires freeze to the ground, and they will up here, you just inflate them a bit to pop the ice and presto, you can drive now.
12-13-2016, 10:24 AM
#8
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Join Date: Jan 2015
Location: Hackettstown, N.J.
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Not true.
Proper inflation pressure is a function of the load vs inflation tables, and a larger tire does not need to be inflated quite as much. Conversely, a slightly smaller tire can sometimes be "crutched" up to meet your car's load requirements with a little more than door plate pressure.
Larger here means Load Index number and whether the tire is designated Standard Load, eXtra Load, or some other description (Light Load, P-metric, maybe more). There is an official procedure for adjusting pressures to suit different size tires, buried in the text that accompanies the load vs inflation pressure tables.
I have a copy of the SL and XL tables and some of the P-metric information . . . and a little home-grown spreadsheet app to do exactly the sort of pressure adjustment you need for size changes involving the SL and XL tables.
FWIW, I do set the same pressures year round for my street driving, but they differ a little from the sticker number for handling behavior that's a little less understeerish. The track driving gets still different pressures (and are measured hot instead of cold).
Norm
Proper inflation pressure is a function of the load vs inflation tables, and a larger tire does not need to be inflated quite as much. Conversely, a slightly smaller tire can sometimes be "crutched" up to meet your car's load requirements with a little more than door plate pressure.
Larger here means Load Index number and whether the tire is designated Standard Load, eXtra Load, or some other description (Light Load, P-metric, maybe more). There is an official procedure for adjusting pressures to suit different size tires, buried in the text that accompanies the load vs inflation pressure tables.
I have a copy of the SL and XL tables and some of the P-metric information . . . and a little home-grown spreadsheet app to do exactly the sort of pressure adjustment you need for size changes involving the SL and XL tables.
FWIW, I do set the same pressures year round for my street driving, but they differ a little from the sticker number for handling behavior that's a little less understeerish. The track driving gets still different pressures (and are measured hot instead of cold).
Norm
Interesting:
.
When I bought tires for my 14, larger size & different mfg., both TireRack & Pirelli said to use the inflation info on the door sill from the mfg. !
One would think people in the tire business would know this stuff..
.
12-13-2016, 12:49 PM
#9
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
People on the engineering side would know that (and a few other things), but people on the marketing and sales sides might very well be unaware.
It still comes down to being a 'starting point' if you're fussy about pressures for any reason. I don't even count the OE sticker pressure numbers for more than that, as they generally have a built-in bias toward understeer and possibly softer cornering response and precision.
Norm
It still comes down to being a 'starting point' if you're fussy about pressures for any reason. I don't even count the OE sticker pressure numbers for more than that, as they generally have a built-in bias toward understeer and possibly softer cornering response and precision.
Norm
Last edited by Norm Peterson; 12-13-2016 at 12:52 PM.
