I looked at my engine air filter today. Holding it up to the light, I can only see daylight in a very few places, a sign that the filter is plugged and needs changing. I was planning to change it prior to the 30,000 mile scheduled maintenance interval but was very surprised how plugged up it is after only 13,000 miles. Interesting factoid "Roughly 14,000 gallons of air are needed for today's cars and trucks to efficiently burn one gallon of gasoline. Dirt equivalent to the size of two aspirin tablets within that air will cause the same amount of wear as 75,000 miles of normal driving." http://www.brakeandfrontend.com/bfed2.htm
do you get the same kind of pollen insanity in the spring that we get over in the Triangle? that might explain some of it...
i replaced mine after 15,000 miles because of the high pollen we have here. one of the drawbacks of the beautiful Pacific Northwest
18,620 Km's and it was plugged a bit of pollen here but ton's of diesel soot in the air, you'd think you were in Europe 25 years ago. Changed the one in the 2k4 at 18,175 Km's as well it was mostly plugged. Nice to know that crap didn't go thru the ICE.
Wow.. I thought the interval was 15,000 miles. I replaced mine around 18,000 miles and it was disgusting!!! The cabin air filter was even worse. I drive on dirt roads quite a bit.
That "factoid" is completely wrong... Stoichiometric is 14.7:1, so it's 14.7 Gallons of air for every gallon of fuel- they're out by a factor of 1000... A more telling figure is the flow rate, ie cubic feet of air per minute.. A blocked air filter will impede air flow, however this is only of major concern for large displacement conventional engines (ie, >2.0 L displacement and high RPMs). The Prius, with it's small displacement and limited revs, needs less than 300 cubic feet per minute of airflow at max revs; at a normal operating RPM, the engine needs much less than that.. What this means is that it takes a significant filter clog to cause a noticable degradation in ICE performance; it also means that something like a K&N filter will produce zero benefits beyond not having to dispose and replace the filter and instead being able to clean and reuse..
Mea Double Culpa. Double sorry! I was careless and posted to the wrong thread. Maybe a moderator could move it??? My recollection was 13 gallons of air to 1 gallon of gasoline but I wasn't totally sure so that's why I looked it up. Seems the source I found wasn't correct.
Another source states "Purpose: The air filter traps dirt particles, which can cause damage to engine cylinders, walls, pistons and piston rings. The air filter also plays a role in keeping contaminants off the airflow sensor (some fuel-injected cars) and sometimes in cleaning the air that enters the crankcase for crankcase ventilation. The air filter also serves as a silencer for your car?s intake system. Your car's engine can use more than 10,000 gallons of air for every gallon of fuel burned, so it?s easy to see how big a job the air filter has." http://www.carcarecouncil.org/Fuel_AirInta...ir_filter.shtml Stoichiometrically speaking, whom am I to believe?
Actually, I made a fundamental error- the 14.7:1 ratio is a mass ratio (14.7 pounds of air for every pound of gas). So, based on the densities of air and gas the volume ratio for stoichiometric burn is actually around 9800:1 at STP. Depending on temperature and formulation of the gas, this ratio can change slightly, but not by a huge amount, and generally, because of oxygenates in the gas, the air ratio goes *DOWN*, not up, so while 10000 might be possible in certain conditions, the correct wording would be "as much as", not "more than"..
if you take the cover off the air cleaner box and don't take the filter out your looking at the clean side of it. The outside air enters the bottom flows thru and then enters the ICE's throttle body. So take it out turn it over and look at the dirty side.
I think air and oil filtration is too important to take a chance with lowest bidder stuff. I plan to stick with OEM despite the higher price.
The Wix and Purolator ones are quite good, you can get Wix products for a very low price at filter1.com. As for the engine air filter, 13K is not uncommon if you live in a dusty area which may cause the filter to load up quickly with dirt. Mike
Stopped at WalMart yesterday; they don't list a Fram (or anything else in air filters) for the Prius. They now carry a limited line of K&N filters. Most of what I've read about K&N filters has not been good. rpm
