0W-40 would be best, but 0W-30 won't hurt in the winter. Come summer, back to the OW or 5W-40. If you had a turbo, I would recommend nothing but 0W in the winter.
2011 A4 2.0T MT6 (118k)
Premium Plus; Colgan Bra
2003 A6 2.7T MT6 (winter beater 240k) - SOLD
Premium-Cold Weather; Colgan Bra
GIAC-Bailey DVs-Samco TBB-K&N
AWE Stage 2 Clutch+Lightweight Flywheel
Billy Boat Downpipe Kit; SS Brakelines