More numbers say: manual is more efficient
Update to this thread:
After nearly 260,000 km tracked in our fuel log by 33 Micra owners over 650 fill-ups, the manual transmission cars are using 10% less fuel than the automatics.
On the fuel log page, click the link below the header to compare the fuel economy average of the automatic vs. manual transmission Micras:
Keep in mind even though it's a lot more data, this isn't a purely scientific comparison. For example, maybe more people who have an urban commute choose the automatic for convenience, so their fuel economy results would drag down the average of the automatics.