Agreed, Turbolight 10W40 was like water. Used to disappear on my SR20DET and RB25DET, both of which were healthy engines (the SR reasonably stressed and the RB babied but getting on in km's.) Wouldn't ever use it again. Both my SR and RB loved Penrite Semi Synthetic 15W60, both ran quieter, smoother, idled better, temps and pressures remained better. And you would drain basically what you put into it, no dissapearing acts here. I'd definitely use it again on a highly stressed or slightly older engine. Tried running the Cube on it, engines too young and tolerances are too good so it was far too heavy and consequently made the engine noisy and sluggish. It would also have trouble starting on a cold morning, splutter and carry on like a bitch. Switched to Penrite Synthetic 5W60 and it runs like a dream. Quiet, revs better, starts instantly.
Amazing how much a different oil effects the way a car runs. No harm in trying a different oil for a short period to see what works for you.