I replaced my engine air filter and the cabin air filter today. The engine one was actually pretty clean relative to the cabin filter. The cabin filter was completely black and even ripple gaps were filled with dist. Also, had some leaves in there as well. It probably hadn't been changed EVER in the 44K the car has.

Compartively, the engine filter was a nice shade of black, but the dust coating was very very thin..enough to make your hands black when touching it. No debris within the ripples. I switched it out anyway, but kept it in case there's some more life in it.

The end results of this seems to be slightly better throttle response (imagination?) and definitely more cabin air flow.

What's the likely impact of a clean air filter vs a dirty one?
Does the description I gave of the engine air filter sound like it needed replacing? Anyone got a pick of a dirty one?

Thanks.

 

With a dirty air filter you lose performance and gas mileage. For the most part, it sounds like you could used compressed air and clean off the filter and it should still be good to go. If it doesn't come clean enough then you should change it. If you can hold it it up and see light through most of it then it is ok. A clogged air filter probably requires the ecu to compensate for the lack of air flow and adjusts the a/f mixture causing a decrease in gas mileage.

 

Ahhh...that makes me feel better about it being so expensive. Might make up some of that $25 now with gas. Thanks.

 

My husband has been getting increasingly bad fuel consumption on our diesel F-250. He finally decided to have a look at the K&N Filter. After pounding out about 1 cup of crap from the filter, the truck is now up 4-5 mpg from where it had been running.