Gino

I know I should know this, but was anxious to get the 930 out of the garage during our short break from outrageous weather here in New England, and did an air pressure check on my tires.

Prior to bedding her down for the last 6 weeks, I made sure tire pressures were approx 35 up front and 40 in rear on 225/50/16 and 245/45/16 respectively. Tonite's reading was 25 and 30. Can that be? Or, is what I'm seeing the 25oF temperature effect from the environment/ garage?

Curious, should I add more air before my ride tomorrow? Check it after the ride (temp will be around 35oF) when the tires warm up a bit? Don't bother?

Gino

OK, while I waited for an answer, I searched on the Web and found something from Tire Rack, Click and Clack Brothers, among others. For each 10oF of temperature change, the tire pressure changes 1#. So when I placed air in the tires before the 'Big Chill' (maybe it was 50-55oF), I should expect to see 3# less in the tires now... but, that was about 6 weeks ago, so maybe there's also some amont of leakage too... I'll give it 2#s.

That explains 1/2 the drop of 10# in each tire... what gives?

I plan to add 5+#s to each before the ride and check after. I should see a rise in pressure because of driving of approx 3#s for 20 minute ride, and another 1# for another 20 minutes... + the 5#s I'm adding. That should get me at approx 33# up front and 38# in the rear when I arrive at work.

I believe that should be safe. Comments?