High flow cabin air filter for reduced blower motor load
 

I just realized that my blower motor is rated at 300W at full speed (higher than my two 120W radiator fans combined). This is a pretty significant draw at lower speeds around town. Removing my moderately-soiled cabin air filter seems to increase the air flow by quite a lot. If I can reduce the blower motor power by ~50% by removing the filter, or getting a high-flow cabin air filter, I figure that would result in a pretty decent gain in fuel efficiency.

This guy over at TDI forums replaced his air filter with some pantyhose over a mesh frame. I'm looking for a more traditional solution. Anybody know of any high flow cabin air filters available?

I'd just knock a hole in an old filter. You'll never save as much in fuel as you spend on a new filter.

I don't know about any high-flow cabin filter, but would rather resort to that makeshift with a pantyhose instead of running no filter at all.

The more air a blower moves the more power it draws so putting in a high flow filter or removing the filter will make it use more power.
The only way it would use less power is if you put it on the high setting before and now you only turn it to the second highest setting with the high flow filter.

Since there would be a lesser restriction to the air flow, it doesn't seem so likely to require more power to blow that greater air mass.


This sounded to be the case.

Except then you would be dissipating the extra power across the blower resistor.

The resistor isn't used when on the highest setting.

No. But it is (and consumes power) when you choose a lower setting.

And here are some measured numbers from my truck: http://ecomodder.com/forum/showthrea...raw-18678.html

The heater blower draws less net power at lower speeds because the decreased power from the motor is much more than the increased power into the resistor.

K&N makes cabin filters now.

Never have to buy another cabin filter again....