Anyone try the BMC filter for the X5 Diesel?
 

Anyone try the BMC filter for the X5 Diesel?

Is it worth the $130 USD?

http://www.bmcairfilters.com/car-fil...20_d776_5.aspx

Absolutely no way.

First, its a turbo. The air filter is not a significant source of restriction. (Actually even on NA motors, but especially on forced induction.)

Take the air filter out- how much power will you gain? VIrtually nothing, IMO. On a turbo, nothing. On a NA, maybe 2%.

So why put in a "performance" filter?

ALL performance filters trade airflow for filtration- you buy this crap and you let more contamination into the motor. Period. This contamination shows up in the motor oil, increasing bearing wear....

But the "Need to Mod" power is strong- people like to make their car special, and LED lights, air filters, CAIs, and other nonsense are cheap mods that make them feel good about their car. The REAL mods- that change performance in significant ways- are priced well outside the range of most, or require extensive work that they cannot do.

Change your stock, highly efficient OE filter with every oil change (so that you are not running a filter to the end of its life when it is fouled and restrictive) and you'll have virtually the same airflow as a so called performance fulter, but with the protection of OE.

I agree to a point... however, you do realize that BMC makes air filters for F1 teams and some BMW OE applications (M3 CSL), right? so it's not like we are talking about K&N here.
But duly noted, was only wondering about its effectiveness in our x5d turbos.

I don't understand the relevance of the F1 reference.

It is exactly like a K&N. Claims of more power due to increased airflow, with no loss of filtering efficiency. Doesn't compute. And certainly isn't worth spending money on.

But you do see the relevance to BMW using BMC filters in their cars vs. K&N, yes?

I don't know anything about the CSL air filter. But when I looked it up I saw a pleated paper filter, as I would have expected. So no, I don't see the relevance of a comparison to an oiled foam filter for a completely different vehicle and engine.

The issue isn't whether they are an OEM supplier or not. It is whether their claims of additional HP by using a different filter are reasonable and whether their filter is worth $130.

Not in the least.

You seem to be falling for the "they use our brand in a race car, it must be good for your grocery-getter" logic.

RACE CARS NEED NO AIR FILTERS. Do you not 'get' this? They are rebuilt regularly... running minimal viscosity, or allowing contamination into the motor are both fine compromises for a race motor.

There is no such thing as a free lunch- you trade flow rate for efficiency. It doesnt matter what names you wrap around that, the physics does not change.

Ya, Im probably falling more for the "BMW USES THIS FILTER IN THEIR SPECIAL EDITION CARS FOR PERFORMANCE ENHANCEMENT"

That's alot of hate for this product with absolutely no science behind it :rolleyes:

OP, I think you are just looking for someone to say "Yeah, use this filter. Car feels much faster after I changed mine out", but I don't think you are going to get that here. Both of the people who already responded are trying to explain that it isn't worth it, but you don't seem to want to hear that.

I remember someone dyno testing a BMW K100 motorcycle many years back (not turbo, of course). They dyno tested it with the regular filter, the regular filter with 80% of the surface covered with plastic wrap, and with no filter at all.

Guess what? No difference whatsoever.

Now, I am not an engine tuner by any measure; however, a friend who does have a lot of expertise in tuning engines once told me that reducing the air filter restriction on a NA engine almost always will do nothing for you unless you take other additional measure to increase airflow, e.g., an exhaust system which flows freer, head work/porting, etc. He said he has never seen a stock engine where the air filter restriction was the weak link or "choke point" in the airflow. Which makes sense, as if a simple improvement in the air filter would increase performance, surely the manufacturer would have already done this, as it is a very easy and inexpensive thing to do.