air filters

M

matt43

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I have a 04 4Runner Limited that is in need of an air filter change. I never do the maintenance myself but was thinking that they usually are really easy to change. Anyone know if that is true of the 4runners as well. Also, how often do they need to be changed? i've got 23K on mine and it has never been changed and I'm noticing a drop in the gas mileage. Figuring that that might be one of the reasons.
 
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matt43,

changing your aif filter is probably one of the simplest things you can do....just open your hood and open the filter box and replace the filter....thats it!.....this may solve your mpg problem...but don't forget to check your tire pressure too.
 
Air Filter

just purchased 99 Limited 4Runner loaded and superb condition (65K miles super clean never off-road). Took recomendation of forum and friend and installed K&N life time air filter...noticeable acceleration improvement and gas savings...easy to install.
 
Yeah the air filters are super easy to install. I would recommend a K&N but remember that most of the performance improvements will be minor your not going to smoke your tires or make 30mpg. :) However it is still worth upgrading to a K&N
 
I highly doubt that an air filter with 23 k miles, is responsible for your sudden decrease in mileage, unless you drive on dirt roads. Somewhere between 20 to 30 k miles is fine for a replacement schedule. I would check your tire pressure. The change in summer fuel composition could be responsible for the decrease as well?
 
While I have a K&N filter in three of my current vehicles and have had them in other vehicles I've owned in the past, I will not use them any more after reading one of the extensive filter tests online a while back. The 'performance gains' versus the contaminants passed through makes it not worth it.

Ricky
 
An understanding of the physics of intake air flow, and the relationship between an air filter and a throttle in a gasoline engine would lead one to understand that air filter restriction does not have an effect on gasoline mileage, as counter-intuitive that might seem at first blush. Air filter restriction will have an effect on wide open throttle performance, or maximum power developed.

For a diesel engine, i.e. an engine without a throttle (using the technical definition), a restrictive air filter would have some effect on efficiency and mileage.
 
I and many others with the True Flow air filter will tell you they noticed a jump in MPG, and power. This is no joke.
 
TrueFlow filters are pretty sweet! I noticed a HUGE gain when I put my intake on. They also clean better than any other filter on the market, and breathe well too. Check out the demo at TrueFlowFilters.com

Brett
 
iFORCE said:
try the new TRUEFLOW filters from burtman industries. best ones IMO for our 4th gens.

FOR V8's http://www.burtmanindustries.com/zoomprod.php?id=4run_truflo_03u_v8
Click to expand...

Wanted to let everyone know that I have about 10 of these filters left. It's one of the best air filters for the 4th gen V8. True flow went out of business and I bought their remaining stock of filters. This is a lifetime filter, and never needs to be changed. You will notice a bump in gas mileage and more power.

You can read more about other with this filter here as well:

http://www.toyota-4runner.org/showthread.php?t=14215&highlight=true+flow+air+filter
 
I stick with paper Wix air filters.

Remember, the more air flow you have through the filter, the more dirt you will allow into the engine.
 
I want to reinforce what others have stated in this thread:

Air filter restriction has no effect on miles per gallon. A restricted air filter looks no different to the engine intake system than a partially closed throttle butterfly. So there is no effect at anything less than WOT. At WOT a pressure drop through the air induction system (such as from a filter restriction) manifests as lower torque due to less air/fuel charge in the cylinder.

Keep in mind that the MAF with O2 sensor feedback will always hold the air/fuel mixture optimal and if this doesn't happen, the check engine light will trigger along with an OBD code.

I might also add that the very fine particulates that get through the air filter may pass across the piston rings and end up in the engine oil, which is a reason to change oil relatively frequently as the oil filter may also not filter these.
 
jeober said:
I want to reinforce what others have stated in this thread:

Air filter restriction has no effect on miles per gallon. A restricted air filter looks no different to the engine intake system than a partially closed throttle butterfly. So there is no effect at anything less than WOT. At WOT a pressure drop through the air induction system (such as from a filter restriction) manifests as lower torque due to less air/fuel charge in the cylinder.

Keep in mind that the MAF with O2 sensor feedback will always hold the air/fuel mixture optimal and if this doesn't happen, the check engine light will trigger along with an OBD code.

I might also add that the very fine particulates that get through the air filter may pass across the piston rings and end up in the engine oil, which is a reason to change oil relatively frequently as the oil filter may also not filter these.
Click to expand...


I agree. With my Harley, I notice some gains with a K&N because it gets WOT and my T4R usually doesn't.
 
Wanted to let everyone know that I now have about 4 of these filters left. It's one of the best air filters for the 4th gen V8. True flow went out of business and I bought their remaining stock of filters. This is a lifetime filter, and never needs to be changed. You will notice a bump in gas mileage and more power.

You can read more about other with this filter here as well:

http://www.toyota-4runner.org/showthread.php?t=14215&highlight=true+flow+air+filter[/QUOTE]
 
sorry about bringing this back from the dead, but since burtman doesn't seem to have any trueflow filters left I found some. Only problem is their for the v8. By any chance is the V8 and the 4.0 V6 (which I have) the same?

Thanks
Judd
 
05 4runner said:
sorry about bringing this back from the dead, but since burtman doesn't seem to have any trueflow filters left I found some. Only problem is their for the v8. By any chance is the V8 and the 4.0 V6 (which I have) the same?

Thanks
Judd
Click to expand...

It doesn't look the same. The V6 has a taper on one of the sides, whereas the V8 is sqaure/rectangular.
 
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