sorry if this is posted in the wrong section Ive just bought a 09 Aveo 1.4 LT ive been looking at the service booklet to see whats required for the 30,000 service as the dealer only did an oil and filter change im confused as to what maintenance is required for this car in the service schedule it says 1.4D and 1.4S 1.2D what does the D and S stand for ? are they different models? I would like to know whats relevant for my car Please any ideas ?