I bought the Lumina new. It is mostly driven around town on short trips and since it has a remote starter and we live in Northern PA, it usually idles about 15 minutes every winter morning. Oil changes varied between 3,000 and 7,000 miles with brand name 5W30 oils. At 67,000 miles, it started using a quart every 850 miles. At 70,000, I switched to 10W30. No change whatsover. At 73,000, I switched to Castrol GTX High Milage 10W40 (thicker oil that the manual calls for). Too early to tell for sure but it seems to be reducing consumption. I know there are a lot of knowledgable people here. What would be the best choice of an oil in this situation? I prefer to use something common that you can buy at Wal*Mart...not the speciality type oils I see some on here recommending. Also, what change interval should I use at this point? Thanks in advance!