Quote:
Originally Posted by boostm3
Ive got a friend with an N54 335i who just told me he just took a 65 mile trip, and with his dual cone intake, averaged 34 mpg for the trip using highways! I, with my bone stock N55 135i averaged, at my best, 28.3 miles over a 200 mile distance using all highways.
I thought that if intakes work, they provide more air flow to the engine for which the ECU, in turn, orders up more fuel to keep the mixture from leaning out under the added air assault, resulting in worse gas mileage, not better.
Does what he told me make any sense??
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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.