[quote author=jarry link=topic=134349.msg2899638#msg2899638 date=1233286658]
Btw I'm an engineer for a tire company.
Excellent, somebody who ACTUALLY knows what they're talking about here! That's a rare occurrence!
Siping is made to trap very small pockets of snow and ice because nothing adheres better to snow and Ice than more snow and Ice. If you question this go make a snowball, and then try to stick it to something else. This goes back to Adhesive vs Mechanical traction.
I actually knew that!
The racing car with the narrow tires also has spiked and studded tires. So digging through the snow and getting down to ice and possibly ground is much more effective for them. But we don't have spiked studded tires. If it were a real advantage, we'd all have 4 donut spares on for winter driving.
I didn't think about digging down to the ice / ground, but I knew the tires were spiked. You win this one. :lol:
The 4.7 psi drop is from some engineer getting too picky with the numbers.
The idea is to hold your tires at a constant Volume between Summer and Winter. So basic chem, ideal gas law PV=nRT. To hold the V constant ,n and R are the same so P1/V1=constant and you can set the 2 equal. P1/T1 =P2/T2. Temperature has to be in an absolute temp scale so you have to change degrees Fahrenheit to Rankin. If you are looking at the difference in tire pressure from 10F to 80F. 10F=470R, 80f=520r. P2/35= 470/50. P2=31.6 psi which is a drop of 3.6 psi purely from the temp difference. If you measure from 90F to 0F you get a 4.7 psi drop.
Can you translate this for those of us that suck at math? Winter tire pressures up or down?
Thanks for your information though. Now, can you go through the hundreds of "this tire is better than that tire because" threads and straighten them all out? :yap: