peanut

I would suggest that this huge oil useage hasn't just suddenly happened without warning unless there is a leak (not evident) or a sudden failure or defect ( none noted).

It won't hurt the engine in fact that amount of oil useage would effectively be a complete oil change every few thousand miles ! The engine is obviously still running fine . My advice would be to keep driving it and budget for an engine rebuild . Alternatively is money is no object I would rebuild it sooner than later.
personaly i would just drive it.

peanut

I find it hard to believe that a Porsche specialist garage with all their equipment and experience couldn't do a better diagnosis than yourself but if thats the case you should know the answer already I guess.
but I wish you well anyway.
We are all 944 enthusiasts at the end of the day

Lee Zook

Check your type of oil. Is it synthetic? I was running a fully synthetic oil in my 86 turbo and was using a quart every 400 miles. I was concerned about the sudden increase in consumption - thought I might be loosing oil through the turbo (no large puddles)- and started searching the 944 turbo forums. There were several threads where people reported high oil consumption with several/many synthetic oils out now. They recommended using Valvoline VR1 racing oil. I started using using the 20W50 VR1 oil and my consumption has dropped significantly back to normal levels. I did nothing else. You might want to try that as $40 in oil is a lot less expensive than a lot of the other work you are thinking about.
Lee