Kiss and make up or I'll do it for the both of you Just to throw in my opinion though I have no job titles or qualifications to throw around to quantify my knowledge, but, and not cause I fancy Rick but to me it is apparent that the two events are different both in nature, and condition it occurs that it does not seem obvious to me to characterise both by the same name? Now, when you lift off the throttle, pre-charged air is trapped (and to some extent, compressed) between the expeller and the throttlebody, and as a result, backpressure, whatmay have you, is going to try and stop the turbo from spinning via frictional resistance of the air...as in, the turbo is stalling, hence, stall. Now, whilst I haven't done enough research into turbocharger Surge, the very name suggests that this phenomenon is the inability of a component of a certain system to process a surplus of a certain flow - hence, in the turbo example, I think its the inability of the engine to cope with the amount of air being forced by a turbocharger, which I know can be destructive. Anyway... Usually when a name is given to an event, it doesn't leave much to the imagination - a Surge is a surge, as in an overpowering or overflowing of a system, whereas a Stall, is a stall, its when movement suddenly or quickly ceases. Feel free to correct me, but I seem to think that these two terms describe concisely what happens in each situation, how can one name be given to both when it is not the same type of event? Is a stall a "negative" surge?! I would continue and wikipedia turbo surge to add to my personal explanation, but at this point it's just a fruitless contest of who's more right than who, I've just explained what makes the most obvious sense to me.