My 13 Passat TDI SE has recently dropped fuel mileage from 40-42 to 37ish. I am driving the same route every day. Two weeks ago I had the 100k mile service completed. I had new tires installed last weekend. Today I had the alignment checked. We have had consistent weather (sunny). This is odd. If it continues next week I will schedule an appointment to have the brakes checked (to make sure one of them isn't dragging). Other thoughts?