Engine Air Filter Change

Rick Grahn · 11-11-2005, 09:20 PM

I recently changed my engine airfilter...the original was very dirty (after 25,000 miles of city/tollway driving). I've noticed about an average 2 mpg improvement in mileage since then. Is this possible? Before others respond that it must be related to driving habits, my route, speed and driving habits were essentially identical each day. I figure it must be coincidence, but I do not know how much a very dirty air filter will affect the mileage.

Just curious.

galaxee · 11-11-2005, 09:22 PM

dirty air filters impact mpg on all cars. it's easy to change and usually worth it. if it was really filthy it may have been really affecting performance of your ice.

Rick Grahn · 11-11-2005, 09:28 PM

Quote:

Originally posted by galaxee@Nov 11 2005, 09:22 PM
dirty air filters impact mpg on all cars. it's easy to change and usually worth it. if it was really filthy it may have been really affecting performance of your ice.

[snapback]154404[/snapback]

Thank you. That may very well be it.

hdrygas · 11-11-2005, 09:52 PM

Yep a dirty air filter is bad. If air does not get in to the car that is not good. I think I will look at mine.

The Critic · 11-11-2005, 10:40 PM

Answer is YES. An air filter that is loaded up with dirt will reduce air flow, and often causes the engine to run rich, and can be detected by oil analysis thru a low Flashpoint, lowered combustione efficiency, and added wear due to the fuel dilution. Air Filters can become loaded with dirt in as little as 10,000 miles, so it pays to check it at least every other oil change.

smtrader · 11-13-2005, 11:22 PM

Quote:

Originally posted by Michael Wan@Nov 11 2005, 10:40 PM
Answer is YES. An air filter that is loaded up with dirt will reduce air flow, and often causes the engine to run rich, and can be detected by oil analysis thru a low Flashpoint, lowered combustione efficiency, and added wear due to the fuel dilution. Air Filters can become loaded with dirt in as little as 10,000 miles, so it pays to check it at least every other oil change.

[snapback]154437[/snapback]

For sure! I change my air filter every other oil change. I live in Los Angeles and commutes 3-4 days a week, so you know the filter needs changing!!

When I do (just last week) my mileage went up 2mpg, with nothing different on my part. I think it's worth the cost if you ask me...

Brian

Rick Grahn · 11-14-2005, 06:13 AM

Thanks to everyone for your replies. I have learned my lesson...change the filter every other oil change or so.

Brent · 11-14-2005, 04:34 PM

Quote:

Originally posted by Michael Wan@Nov 11 2005, 10:40 PM
Answer is YES. An air filter that is loaded up with dirt will reduce air flow, and often causes the engine to run rich, and can be detected by oil analysis thru a low Flashpoint, lowered combustione efficiency, and added wear due to the fuel dilution. Air Filters can become loaded with dirt in as little as 10,000 miles, so it pays to check it at least every other oil change.

[snapback]154437[/snapback]

Agreed. I live in So Cal and I let my filter go for 11,000 miles... then replaced it and saw an increase of 2 MPG with no other changes. I think I'll change it with every oil change from now on.

jeromep · 11-20-2005, 04:46 PM

Yes, it is really quite possible that you would see that much of an increase after chaning out an obviously dirty air cleaner. But this condition is only valid if there were no other changes to your vehicle, such as changing the air pressure in your tires, etc.

Assuming no other changes in the car (control group) and all you did was change your filter (experiment condition) then the improvement you see is directly related to the air filter.

galaxee · 11-20-2005, 05:05 PM

Quote:

Originally posted by jeromep@Nov 20 2005, 04:46 PM
Assuming no other changes in the car (control group) and all you did was change your filter (experiment condition) then the improvement you see is directly related to the air filter.

[snapback]158702[/snapback]

a post after my own inner science geek's heart!

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11-11-2005, 09:20 PM	#1
Rick Grahn Senior Member Join Date: Nov 2004 Location: Illinois Posts: 285 My Car: 2005 Prius Model: Package: #9 Thanks: 1 Thanked 0 Times in 0 Posts Friends: 0	I recently changed my engine airfilter...the original was very dirty (after 25,000 miles of city/tollway driving). I've noticed about an average 2 mpg improvement in mileage since then. Is this possible? Before others respond that it must be related to driving habits, my route, speed and driving habits were essentially identical each day. I figure it must be coincidence, but I do not know how much a very dirty air filter will affect the mileage. Just curious.

11-11-2005, 09:22 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	dirty air filters impact mpg on all cars. it's easy to change and usually worth it. if it was really filthy it may have been really affecting performance of your ice.

11-11-2005, 09:52 PM	#4
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 0	Yep a dirty air filter is bad. If air does not get in to the car that is not good. I think I will look at mine.

11-11-2005, 10:40 PM	#5
The Critic Senior Member Join Date: Oct 2005 Location: Santa Cruz, CA Posts: 112 My Car: Other Non-Hybrid Model: N/A Package: N/A Thanks: 3 Thanked 7 Times in 6 Posts Friends: 0	Answer is YES. An air filter that is loaded up with dirt will reduce air flow, and often causes the engine to run rich, and can be detected by oil analysis thru a low Flashpoint, lowered combustione efficiency, and added wear due to the fuel dilution. Air Filters can become loaded with dirt in as little as 10,000 miles, so it pays to check it at least every other oil change.

11-14-2005, 06:13 AM	#7
Rick Grahn Senior Member Join Date: Nov 2004 Location: Illinois Posts: 285 My Car: 2005 Prius Model: Package: #9 Thanks: 1 Thanked 0 Times in 0 Posts Friends: 0	Thanks to everyone for your replies. I have learned my lesson...change the filter every other oil change or so.

11-20-2005, 04:46 PM	#9
jeromep Join Date: Dec 2004 Location: Eastern Washington State Posts: 821 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Yes, it is really quite possible that you would see that much of an increase after chaning out an obviously dirty air cleaner. But this condition is only valid if there were no other changes to your vehicle, such as changing the air pressure in your tires, etc. Assuming no other changes in the car (control group) and all you did was change your filter (experiment condition) then the improvement you see is directly related to the air filter.