Quote:
Originally Posted by thez99
Yes and no..
I think yes he is full of shit getting that much, is he stock otherwise? I mean if he IS stock with his only mod being a DCI that kind of shows a lot bout his reliability with information like this 
However, with this engine and really any FI engine, its not like the DCI is giving an "air assault" like you put it at all. Basically the engine needs to take in a certain amount of air for turbocharging depending on what rpms you're at and how close n far you are from WOT. I have a DCI I added about 3 months ago and Ive only seen MAYBE 5-10 less miles per tank overall, and thats mostly street/backroad driving, not alot of highway.
Its not like as soon as you add a more open intake your ecu just automatically says "OK MORE FUEL" no matter what. Now sure if you're in 5th going 60 and you go WOT back into 3rd then sure you'll be putting out a little more fuel with the DCI installed for basically the reason you gave. But realize that with a FI engine, specially one that's tuned, you NEED the most open and unrestricted airflow possible for the best overall performance and efficiency of the turbo's, so anyone who passes on a DCI because of mpg issues...need to rethink some things.
P.S. Basically heres how you need to think it..If you plan on driving this car like a granny, never going above 3500 rpm or ever touching pedal to floor like its supposed too, then you dont need a DCI. Otherwise, just do ur engine favor n get one, and please not one of the $400-500 rediculous ones, BMS dual oiled filters are $100 and the way to go. |
That 'air assault' metaphor was nothing more than a figurative device to cover the idea that, if more air reaches the engine, the sensors will report the increased airflow or mass, whichever this car uses, to the ecu, which will, in response order up more fuel to keep the mixture stoichiometric. I was questioning whether its logical to expect an increase in gas mileage, as reported to me, in a situation where more fuel is being used.
Perhaps, however, its possible that no more air is really entering the engine due to possible other restrictions, ie, throttle body size, etc. If no more air enters the engine, and no more fuel is used, its possible that the intake, rather than accomplishing a greater air mass/volume, is simply allowing a more efficient flow, and perhaps that could be the cause of any increase in gas mileage reported as a result of using a DCI. Still, Im not sure that providing a freer, more efficient flow doesnt also result in greater air volume or mass to the engine, resulting, once again, in more fuel useage.
Where's an automotive engineer when we need one
