I have been using DINO 5w-30 oil for the last 70K miles. Since going with a larger turbo last year I finally decided to try synthetic and I recently switched to Rotella T6 5w-40. About 1500 miles after switching to synthetic, I noticed that the engine was about ½ a quart down and topped it off. Now that I am at 3000 miles the oil is again down ½ a quart. I never had any oil consumption with DINO and I was wondering if it makes sense to stay with synthetic or switch back?