Steps for Winter Storage for your Porsche:

1.  Older cars with steel fuel tanks - fill tank with gas (Sunoco 94) and add fuel stablizer to the tank.  Newer cars with plastic gas tanks do not need to be full of fuel but, do add fuel stablizer in proportion with amount of gas in the tank.

2.  Get a battery tender or trickle charger.  It shuts off automatically when the battery is full charge.  Charges battery at 1 or 1.5 amps.  Take the key out of the ignition.  This way you'll be ready for Spring.

3.  Fill tire pressures to 45-50 psi for storage - this prevents flat spotting.

4.  If you change your oil every 3 - 5K miles - you should be fine for storage.  The Porsche guys who wait for 15K miles are allowing acids in the oil to remain all winter, which is corrosive.  Check your owner manuals - the Factory recommends changing the oil every 15K miles or ANNUALLY.

5.  Make sure your coolant was flushed every 5 years and the protective temp of -20 deg. for our area.