Its to do with what type of fuel management the car is using when you first fire up. I wont say more as its quite complicated and not of much use to many folks, plus I only have a basic grasp of it from talking to clever electronics and tuning people.
The basic thing is that it takes several minutes to get the car to settle down as the sensors that are in the MINI are not the worlds best and there are not a great number of them there to feed info to the ECU to ensure correct fuel. It is all a bit on off which makes that rather surge type feeling when cold.
Its usually nothing to worry about and its usually only seriously prominant when cold and you boot it immediatly, which is not a good thing anyhow. Turn the engine on for about 3-5 mins before you drive anywhere and it generally gets enough heat in and settles down on the fueling to make the initial dive away a bit nicer.
Also as you tune the car it seems to becomes more obvious, for understandable reasons.
Thats my inderstanding, after talking to some clever MINI tuners, of why this happens on the S more than on the Cooper/ONE |