Hmmm..that would explain the sort of rough idle, slight miss at part throttle, lean-ish looking spark plugs, and really good mileage! Not so good for longevity though, so I better look at what the causes and cures are. I also wonder how accurate a tire gauge, calibrated for air, matches with a liquid....

As far as the oil thing goes, at 1200 miles, I've only burnt 1/2 quart, which is a massive improvement. And although the engine was not sludge-y looking, everything I see from the oil fill cap has gone from golden colored to nearly new kind of clean. That's 1200 miles with the Auto-Rx.....