[mythek]

Hi there,

I've been searching around for this answer but no luck, hopefully some of you can share some experience with MPG (miles per gallon) improvement after installing a true cold air intake like (stett or dinan) or dual cone intake (bms/injen/afe). I know that installing either one would give our n54 a little power, but what happens to the MPG?

Thanks for your time

[BQTuning]

Well of course you will have better MPG gains with a CAI over a DCI

[TitanLH8]

Might be lower due to more revving and spirited driving haha

[BEAR-AvHistory]

It will go down because people like to listen to the noise.

[Wedge1967]

Running FBO with AFE Stage II on COBB stage II sport ST OTS. Got 29 mpg on a 600 mile drive yesterday.

[mythek]

so generally since it provides better efficiency, it would have better MPG assuming you don't gun it all the time just to hear the engine roaring?

I'm thinking about just getting a BMS DCI because it's cheaper and honestly, i'm only trying to get more efficiency...I will not be pushing the gained horsepower. Do you guys know if the BMS DCI would have a negative effect on the n54 engine in the long run?

I appreciate all the inputs. I'm a new e92 owner. I just took my car to a little photoshoot, I will be posting some photos soon

[914kid]

I used to get 410-420 to a tank but after the DCI my next fill ups were around 320-330 LOL. Now that I am used to the noise it went back to 400+.

Moral of the story is that DCI don't improve MPG.

[E90Company]

Originally Posted by mythek

so generally since it provides better efficiency, it would have better MPG assuming you don't gun it all the time just to hear the engine roaring?

I'm thinking about just getting a BMS DCI because it's cheaper and honestly, i'm only trying to get more efficiency...I will not be pushing the gained horsepower. Do you guys know if the BMS DCI would have a negative effect on the n54 engine in the long run?

I appreciate all the inputs. I'm a new e92 owner. I just took my car to a little photoshoot, I will be posting some photos soon

Not really. If you arn't pushing your car you arn't requesting much boost, therefore an intake wouldn't do much for you. Plus, the DCI's they sell are all oiled filters, which don't filter as well as OEM or paper. If you are keeping the stock tune on, don't even look into changing your intake.

[335scott]

You guys. Pulling in hotter air is going to yield better mpg. Colder air is better for power. DCI will give you better mpg

[AK 335i]

LOL.. I run no intake on my 6466 (OMG) and got 29MPG on a 200ish mile drive home in the car

Its all in how you drive the difference with any intake setup on MPG will be negligible and more influence by the traffic you drive in or weather. Good luck on proving any setup yields better MPG you cannot keep all other variables controlled. even the quality of gas could vary slightly in a test. Pointless thread

[E90Company]

Originally Posted by AK 335i

LOL.. I run no intake on my 6466 (OMG) and got 29MPG on a 200ish mile drive home in the car

Its all in how you drive the difference with any intake setup on MPG will be negligible and more influence by the traffic you drive in or weather. Good luck on proving any setup yields better MPG you cannot keep all other variables controlled. even the quality of gas could vary slightly in a test. Pointless thread

Originally Posted by 335scott

You guys. Pulling in hotter air is going to yield better mpg. Colder air is better for power. DCI will give you better mpg

That's not the way it works.

[335scott]

How are you going to say thats not the way it works? Thermal efficiency of an engine is not the same as fuel efficiency of an engine. All you have to do is google hot air intake.
http://www.gassavers.org/f15/how-to-build-your-own-warm-air-intake-wai-244.html

[E90Company]

Originally Posted by 335scott

How are you going to say thats not the way it works? Thermal efficiency of an engine is not the same as fuel efficiency of an engine. All you have to do is google hot air intake.
http://www.gassavers.org/f15/how-to-...e-wai-244.html

Yes but when you put an intercooler into the equation all that goes out the door. The only thing colder air would do is improve the turbo's compressor efficiency by a slight margin. That's why people do pre-turbo meth.

[gtaccord]

An intake (DCI or CAI) will not give you a noticeable increase in mpg.

[335scott]

I can see how an inter cooler would make a difference. The turbos dont have to compress the same amount of air if its hotter though. Use less air use less gas. I will tell you i haven't seen as much of a gain w my 335 dci as i have with my sri on my v6 genesis coupe.

[E90Company]

Originally Posted by 335scott

I can see how an inter cooler would make a difference. The turbos dont have to compress the same amount of air if its hotter though. Use less air use less gas. I will tell you i haven't seen as much of a gain w my 335 dci as i have with my sri on my v6 genesis coupe.

Turbos will "work" less hard when the air is more dense/colder. If the air is hotter, the turbos don't have as much oxygen per square inch (psi), so they need to work harder to take in the same amount of oxygen. Flash tunes do this by increasing the boost using IAT compensation tables. The hotter the air, the more boost, to keep power output consistent. In the case of the N54, IAT is read post-FMIC, so anything temperature before that (the intake air) is irrevelant. You are correct with the bold.