Engine Air Filter

popoff · 10-30-2005, 06:16 PM

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

galaxee · 10-30-2005, 06:26 PM

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...

Mystery Squid · 10-30-2005, 06:38 PM

That's odd... I'm at 22K miles, and it looks brand-spanking new.

DaveinOlyWA · 10-30-2005, 07:02 PM

i replaced mine after 15,000 miles because of the high pollen we have here. one of the drawbacks of the beautiful Pacific Northwest

Frank Hudon · 10-30-2005, 07:51 PM

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.

priusham · 10-30-2005, 08:04 PM

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.

IsrAmeriPrius · 10-30-2005, 08:14 PM

Why is this thread in FHOP? It belongs in Care, Maintenance and Troubleshooting.

c4 · 10-30-2005, 08:20 PM

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..

popoff · 10-30-2005, 08:27 PM

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.

popoff · 10-30-2005, 08:56 PM

Quote:

Originally posted by c4@Oct 30 2005, 08:20 PM
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...

[snapback]147680[/snapback]

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?

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10-30-2005, 06:16 PM	#1
popoff Join Date: Mar 2005 Location: western NC mountains Posts: 560 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	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

10-30-2005, 06:26 PM	#2
galaxee resident lab rat Join Date: Mar 2005 Location: boilermaker territory Posts: 9,676 My Car: 2005 Prius Model: N/A Package: #5 Thanks: 0 Thanked 94 Times in 37 Posts Friends: 26	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...

10-30-2005, 06:38 PM	#3
Mystery Squid Junior Member Join Date: May 2005 Posts: 3 My Car: Model: Package: Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	That's odd... I'm at 22K miles, and it looks brand-spanking new.

10-30-2005, 07:02 PM	#4
DaveinOlyWA 3rd Time was Solariffic!! Join Date: Apr 2004 Location: South Puget Sound, WA Posts: 12,382 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 24 Thanked 122 Times in 104 Posts Friends: 10	i replaced mine after 15,000 miles because of the high pollen we have here. one of the drawbacks of the beautiful Pacific Northwest

10-30-2005, 07:51 PM	#5
Frank Hudon Senior Member Join Date: Jan 2004 Posts: 4,144 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	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.

10-30-2005, 08:04 PM	#6
priusham Join Date: Jul 2004 Location: Michigan - land of everlasting snowflake icon! Posts: 525 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	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.

10-30-2005, 08:14 PM	#7
IsrAmeriPrius Progressive Member Join Date: May 2004 Location: Southern California Posts: 4,338 My Car: 2005 Prius Model: Package: #6 Thanks: 3 Thanked 0 Times in 0 Posts Friends: 0	Why is this thread in FHOP? It belongs in Care, Maintenance and Troubleshooting.

10-30-2005, 08:20 PM	#8
c4 Senior Member Join Date: Mar 2005 Posts: 524 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	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..

10-30-2005, 08:27 PM	#9
popoff Join Date: Mar 2005 Location: western NC mountains Posts: 560 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	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.