Well I was going to add it up but Peter beat me to it.

But, John tells it like it is, a quart every 1000k is OK. Even much more would be acceptable but for the carbon that builds up.

You need to look into the closed loop operation of your O2 sensors.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician