I have a 2006 Camry with 166, 000 miles on and have changed the oil every 5,000 miles and used Castrol 5w30 oil since I bought it with 14, 000 miles on. About a year ago I had to add a quart to an oil change and now I have added 2 quart and still have a 1000 miles until the next oil change. This car has been flawless with this exception. Any ideas? Thinking of using 10w30 at the next oil change. Anyone out there with a 2006 2.4 with similar issue?