It might just have been my excited ears, but during my test drive last night (Before the tach died) I was upshifting at 1400 and cruising at 1000, and didn't hear a sign of lugging, so that's like woah to me, and I know it's different with my mom's car, so I was sorta just wondering....
Mom's 93 camry lugs under 1500 as a general rule, sometimes a bit higher under load in 5th and sometimes starts lower if it were 2nd or 3rd without load or something like that.
Too much rolling resistance to keep the engine running I suppose? Basically like letting the clutch out with no gas when in gear at a dead stop - engine speed can't compensate for the added load. I'll have to do some research...yay!
A few other sites I have found claim that lugging causes detonation in the engine. If this is the case, then a higher octane fuel may provide a way to drive at lower rpm. If it works then it would actually give some truth to the statement of higher octane fuel increasing FE.
I'll check into some more.
EDIT: Virtually every engine re-manufacturer warns against engine lugging when breaking in your "new" rebuilt engine. They all state that it causes detonation plus the "newly lubricated" condition of the rebuild isn't as protected from friction as a "broke-in" engine....
Hmmm, so would an octane boost allow for lower rpm cruising?