[aerobod]

There are lots of possibilities on what could cause a shift in fuel consumption, but often with a significant shift (>10%), it is a problem with closed loop Lambda operation not occurring during light and medium loads. So Lambda sensor contamination, exhaust flow changes to the sensors or wiring damage (although that should set a code), could be a problem.

[Ehloo]

i am more concentrated on the twice a week 250 mile drive. that some serious driving and wear and tear

for the amount you pay in gas wouldn’t something with better mpg serve you better. second commuter car

[priitserk]

Originally Posted by Carefree

High school chemistry and/or physics teaches us the relationship among pressure, volume, and temperature (pvt). A properly designed well intake system addresses all 3 resulting in what BMW engineers intended i.e. a balance of power and efficiency. It makes sense to those of us with a technical discipline.

Sticking an aftermarket cold air intake with paper filters in an open engine compartment is little more than eye candy. It, most certainly, alters the original aforementioned parameters. It’s not complicated.

If you’re heavily tuned, the Eventuri intake system is beneficial (allegedly).

A car cruising 90km/h hardly uses engine power. Air volume it requires is pretty low. Read again, he is cruising on highway. HP to keep an object moving at 90km/h, is around 20.

Honestly some time things tend to just go bad. Murphys law says that shit happens usually when you least expect it. Go to dyno, see what engine parameters show. They will tell you at spot what parameters are not ok and we can trace them back to tuning parts or to other sensors. That MPG difference is huge, something is very wrong.

[Carefree]

Indeed, something is wrong.

Changing the intake alters the OEM design/performance, that’s undeniable.
Replace a turbo or downpipe or tune the ECU. Same result, a change. Again undeniable.
Is it better? Possibly. Is it worse? Possibly. But it’s different.

With the exception of the Eventuri, which allegedly increases performance, aftermarket intakes add noise and nothing else.

[M2M3M3]

Originally Posted by Ehloo

i am more concentrated on the twice a week 250 mile drive. that some serious driving and wear and tear

for the amount you pay in gas wouldn’t something with better mpg serve you better. second commuter car

That kind of a commute on the highway is negligible wear and tear. Much nicer to the car than a 5mi trip where the car never gets warmed up.

If i had to drive 250mi twice a week, a fun car like an M2 is precisely the kind of car i would want to drive.

[Carefree]

Originally Posted by M2M3M3

That kind of a commute on the highway is negligible wear and tear. Much nicer to the car than a 5mi trip where the car never gets warmed up.

If i had to drive 250mi twice a week, a fun car like an M2 is precisely the kind of car i would want to drive.

Agree 100% ^^

Highway miles are a piece of cake.

[spurcap]

Let's step back and think of the point of a high performance intake as a performance mod.

It's easier to think of in the naturally aspirated context but in short ... gasoline engines turn a crank that turns your wheels by moving pistons which are in turn moved by a spark triggered explosion of gasoline and oxygen. The point of aftermarket intakes for performance is generally to get more air into the cylinders or to get colder more dense air into the cylinders. Why? Because the more fuel you burn the more power you create but you need a corresponding increase in air to maintain proper ratios for complete combustion. In the olden days, if you increased air supply, the immediate effect was a lean running engine and you would increase fuel through carb tuning to get back to correct ratios. In modern days, the O2 sensors take care of this. So... in short: a productive high performance intake is functioning properly if you can burn more fuel. The only way improved intake improves performance and doesn't use more fuel is if the engine was running rich before adding it.... e.g. a dirty air filter. In the world of MAF sensors and O2 sensors proper combustion is almost a given. Reduced air = less power because you can't burn enough fuel as the fuel delivery matches the air supply.

You can't create power out of fairy dust. You either simply force in more air and fuel (what a turbo does), you increase compression, or otherwise make the engine(and drivetrain) more efficient which is generally beyond the scope of bold on Saturday afternoon performance mods.

Hear of people tuning their car to get more power? Broadly speaking - this is all about telling the car to give itself more fuel to increase power at the expense of fuel economy.... or, for example upping boost to actually give it more air and fuel as boost in simple terms is simply shoving more air into the cylinders so you can also shove in more fuel.

Getting more power with the same amount of gas (improving efficiency) is very hard as the German engineers that build your car were very incentivised to do this out the door as best as practicible.

This is all based on the intake actually improving efficiency. It is also possible it really does nothing except for looks and you have a problem with the install, your ECU is getting bad data and in turn running shitty (rich).

[Carefree]

Cold air intakes are primarily “noise”, not performance, mods. They offer very little in the way of increased performance.

A pair of BMC air filters installed in the OEM G87 intake provide a bigger performance bump for less money but without the eye candy.