PSI vs hydroplanning

[Q45tech]

http://www.tirerack.com/tires/...f.jsp

Unfortunately the article didn't consider that sudden rain is cooling of the tire, dropping pressure. To maintain 35 psi in rain you may need to be running 38-40 psi at highway speed and summer temps.

So 35 psi cold in morning would be about right.

The weight on rear tires is less than front so in theory you need to run higher psi on rear to increase molecular adhesion.

[Jeff Williams]

It's too bad they didn't show 40 PSI and 45 PSI test runs.

[Q45tech]

I discussed this with Michelin and that's why they run all WET lab tests at 35 psi [constant monitoring and computer adjust pressure while rolling on the test fixture [metal drum].

http://www-nrd.nhtsa.dot.gov/v...e.pdf

http://www.tiresociety.org/booklet_comb ... s/....html

Lot's of difference between oem COLD minimum of 29 psi and 35 psi........notice placard mentions 35 psi COLD for high speeds.