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Old 12-02-2006, 08:50 AM
Earthling Earthling is offline
Pretty Darn Active Enthusiast
 
Real Name: Harry
Location: Finger Lakes Region NY
Hybrids: 2007 Prius
Posts: 264
Default Re: How does the Prius do on snow and ice in the winter?

Quote:
Originally Posted by msantos View Post
hummm... I find that extremely surprising.

In my experience in extreme cold climates (involving slush, snow and ice), the tire traction decreases with a decrease in tire pressure. Again, that is not very safe (according to the Department of Transportation) for motorists in the northern climates.

Cheers;

MSantos
First, notice that I am running tire pressures above what is recommended, not below, so I am not running low tire pressures.

Some Googling comes up with various tidbits:

"RAY: But there are no circumstances when overinflating the tires will help you get more traction. Overinflating leads to a narrower tread patch, less friction and less traction ­ which is why it's associated with slightly higher fuel economy."

from here http://content.hamptonroads.com/stor...778&ran=144851

At the same time, it is unwise to reduce tire pressure for snow and ice:

"Cold weather driving:
  • You should check your tire pressures frequently during cold weather and add the necessary air to keep them at recommended levels of inflation at all times.
  • Never reduce tire pressures in an attempt to increase traction on snow or ice. It does not work, and your tires may be so seriously underinflated that driving can damage them. "
from here:http://www.gm.com/company/gmability/.../you/tips.html

more:

"An executive of Drivers.com recently bought four used tires from a dealer and was told to keep the pressure four psi (pounds per square inch) higher in winter than in summer. Not so."

from here: http://www.drivers.com/article/354/

My point is that traction is critical in northern climates on snow and ice. You can't run tires too low or too high. Inflation needs to be reasonably close to what the vehicle manufacturer recommends. I am getting excellent fuel economy running my Prius tires at 2 psi above recommended pressures. I won't run them any higher than that in the winter due to concerns over traction and safety.

Harry
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