Recommended crankcase oil is 5W30 unless you live in an area of extreme cold conditions then 10W30 may be used. Also, if you are experiencing wild or low fluctuations in oil pressure gauge readings, you may want to replace the oil pressure sending unit as that is usually the culprit for those kinds of readings.
10w30
10w30. Sometimes its stamped somewhere on the dipstick too
ATF? a/c? brake? engine oil? windshield washer?
10w-30 fully synthetic is recommended
5w30 or 10w30
Sounds like a blown head gasket or a cracked head. does the car overheat? check for water in the oil, or oil in the radiator.
Next to the oil filter.
4.54.5
use leak stop or something. Where is your oil leak?
Warm climate, 10W-30. Cold climate, 5W-30.
About 4.5 quarts
105 Inch Pounds.