Lugging an engine with a tiptronic?
 

Can one cause an engine to lug with a tiptronic (e.g. cruising at a low rpm with a high gear)?

doubt it, cars with tiptronic allready have more grunt in the low rpm anyway , it's not as critical as would be with an early S engine.

ok , in manual mode , you could probably get low rpm in high gear
and i doubt there's a point in doing so , but really lugging the engine , you'de have to be really low in RPM

all depends on your engine really, at what point does it begin to produce torque?

The reason I ask is because sometimes when one cruising at overdrive and wish to accelerate quickly, the transmission may not shift down a gear immediately and the car may try to accelerate at 4th or 5th gear slowly. If this happens, then should we manually shift down a gear before pushing for acceleration.

downshifting is fun... go for it

So I guess we just can't rely on the computer to downshift for us, isn't it? and the solution would be to downshift ourselves in order to boost the rpm higher.

if the 'puter thinks it can make it , it won't downshift
but that just means the 'puter is a boring fart , who cares more about fuel economy, not that he can't be relied on.

I was wondering the same on my Wife's CVT Audi A4... Not so much lugging but the tranny will shift to 7th gear any chance it gets (well, 7th is a relative term on a CVT tranny but that's what it says), which does not sound like a great way to "break-in" a new motor !

I've made a point of driving it harder and in sports mode to make up for that...

Lugging per se is impossible on a tip, I'd say.. Lugging is when you press the gas pedal hard at low RPM in a too high a gear. A tip will downshift in that situation. Dirving at low rpm in high gear and accelerating slowly is not lugging !

My experience is that the computer will shift down one gear or two for you 90% of the time when you step on the gas. However, it seems that there is still 10% of the time where the gear will, for example, stay with 4th when you press the gas and the car accelerates slowly because of the low rpm. Will this be similar to a lugging situation?

If the RPM is below 2000 and your foot is floored, then yes, you could be lugging.

It is doubtful though, the "manual" automatics I've driven will all downshift in that situation.

Just check the tach.