The only parasitic draw specs I've found have been in TSB's addressing that issue. GM says .030a is ok. (02-06-03-010A - Jul 2, 2004) Audi says .040a. (27 12 13 2029010/1 March 22, 2012)

It really depends on how big the battery of the vehicle is. The GM TSB says that a .030a draw will kill a fully charged 70rc battery in 23 days. If you have a huge battery (like lots of german cars) you could potentially sustain a higher rate of draw.

The GM TSB says that .007-.012a is normal for most vehicles. I assume they're only talking about theirs, but that correlates with my experience.

Eric Zappe
Owner/Technician
Zap Auto Repair LLC
Portland, Maine, USA