Lately my Cruze has had more lag that usual. I'm used to the slow acceleration the Cruze is known for but intermittently it has been worse. Taking off from stop, it feels like it's practically crawling until it reaches about 3k Rpms and the turbo kicks in and feels like it jerks into gear. Twice within the past two weeks have I been at a light and as I release the brake to hit the gas, the Rpms drop and it stalls out. Also I've noticed a front end rubbing or vibration almost around 25-30 mph. It has not thrown any codes during any of this and my luck if I take it in they won't be able to reproduce anything. About to change the spark plugs and try running premium. Any other thoughts? At 79k on it and i maintenance it regularly.