Aftermarket Air Filters

[GeneW]

Opted to go with a NAPA Gold Air Filter because it seemed thicker and thus more efficient than the Factory filter. Does get dirty a LOT faster. I figure roughly about 5,000 to 10,000 miles per filter. Isn't too bad, cheaper than engine wear.

Negligible impact upon fuel efficiency. I made two long (50 mile) trips yesterday and netted 38 mpg, with cool air (about fifty five degrees fahr) and some "stop and go" and "evading idiots" traffic. Usually my Yaris crests 40 mpg when the ambients go over 80 fahrenheit.

Gene

[talnlnky]

Opted to go with a NAPA Gold Air Filter because it seemed thicker and thus more efficient than the Factory filter. Does get dirty a LOT faster. I figure roughly about 5,000 to 10,000 miles per filter. Isn't too bad, cheaper than engine wear.

Negligible impact upon fuel efficiency. I made two long (50 mile) trips yesterday and netted 38 mpg, with cool air (about fifty five degrees fahr) and some "stop and go" and "evading idiots" traffic. Usually my Yaris crests 40 mpg when the ambients go over 80 fahrenheit.

Gene

yeah... as far as i've been able to read... there is a trade off with air filters, Higher airflow = less filtration/more particles/more HP
Lower airflow = more filtration/less particles/less HP

I can't imagine <1HP being worth the increased wear and tear... I want my engine & everything else to last a good while before I have to start paying for replacements. Hell, I wouldn't mind handing this car off to my kid someday (thats right... i'm not maried, and have no kids right now).

[intake]

foam filters filter more dust and increase air flow
yes, i know, this sound strange, but it's real

[1stToyota]

Unless dust is a problem in your area filters should last longer than 10K miles. Road constuction on the way home sometimes kicks up lots of dust and I just changed out my air filter at 14K and it still looked pretty clean.

[hatchbackkid82]

:biggrin:

[BailOut]

My K&N drop-in panel filter offers no better MPG, either, but I like it for the reusability and lifetime warranty. I clean it every 6 months (I just cleaned it yesterday, in fact).

People love to jaw about filtration and often rag on K&N for supposedly letting in too much stuff but my throttle body and fuel injection housing are as clean as the day I got the car 40k miles ago.

[1stToyota]

I don't think a K&N drop-in has the ability to muck things up like a short ram; the stock air box has a nice little blanket in the upper portion.

[AlexNet0]

yeah... little blanket... cut that stupid thing out... lol

[Kaotic Lazagna]

My K&N drop-in panel filter offers no better MPG, either, but I like it for the reusability and lifetime warranty. I clean it every 6 months (I just cleaned it yesterday, in fact).

People love to jaw about filtration and often rag on K&N for supposedly letting in too much stuff but my throttle body and fuel injection housing are as clean as the day I got the car 40k miles ago.

So do you think an AFE Stage 2 dry intake would improve gas mileage? I know when I went to a stock box from a SRI on my GTI, I lost 2-5 mpg.

[BailOut]

So do you think an AFE Stage 2 dry intake would improve gas mileage? I know when I went to a stock box from a SRI on my GTI, I lost 2-5 mpg.
With a little engine like ours where breathing is never a problem no filter or aftermarket intake is going to help with mileage or power. A blocked filter can certainly impede air flow but any clean filter and system will do.

[1stToyota]

yeah... little blanket... cut that stupid thing out... lol

I like the extra protection, and if I did cut it out the MAF meter would most likely just do its job and readjust for the little bit of extra aiflow that it's now seeing.

[Yaris Hilton]

BailOut's right. Whenever you're operating at part throttle the pumping losses pulling air past the partly closed throttle are what consume wasted energy from the engine, and if you put in a freer flowing intake, you'll just close the throttle a little more to get the same power and are right back where you started. In a system that mixes fuel with air by volume, as a carburetor does, a restrictive or dirty filter will cause the mixture to go rich and lower mileage. An engine control system that measures mass airflow and fine tunes the mixture with feedback from an exhaust oxygen sensor won't richen the mixture under those circumstances, and its mileage won't be affected. Only maximum power will be decreased due to limited maximum airflow.

Pretty much the same applies to cold air intakes. Only thing they can help is maximum power at wide open throttle. Under some circumstances they may decrease engine efficiency and increase emissions, if the fuel's evaporation is delayed by the lower air temperature. Most of the time, with a warm engine, they'll make little difference.

[Kaotic Lazagna]

Hey Brian, does .5 more displacement really do a big difference? I mean, my GTI only had 9 more hp than my Yaris.

YarisHilton, I'm sorry, I kinda got lost in your post (doesn't help that I'm rushing here, I'm also studying for a test).

[Yaris Hilton]

I just explained as simply as I know how that no air filter (or cold air intake) is going to boost your fuel economy. Any observed differences people report are coming from the well known effects of changing anything that you expect to make an improvement.

[1stToyota]

Hey Brian, does .5 more displacement really do a big difference? I mean, my GTI only had 9 more hp than my Yaris.

YarisHilton, I'm sorry, I kinda got lost in your post (doesn't help that I'm rushing here, I'm also studying for a test).

In simple terms, when engines were dumb, as with carburetors, they could be fooled by a HP filter, but new cars with OBD-II watching the airflow isn't going to let itself be fooled for long; it'll adjust to anything new that it's seeing, unless tuning is altered.

[Kaotic Lazagna]

I just explained as simply as I know how that no air filter (or cold air intake) is going to boost your fuel economy. Any observed differences people report are coming from the well known effects of changing anything that you expect to make an improvement.

lol...I actually would have expected the SRI on the GTI to decrease my gas mileage, but it did the opposite. When ever I get some money, I'll see if I'll have the same experience with the Yaris, although I probably shouldn't get my hopes up.

[Kaotic Lazagna]

In simple terms, when engines were dumb, as with carburetors, they could be fooled by a HP filter, but new cars with OBD-II watching the airflow isn't going to let itself be fooled for long; it'll adjust to anything new that it's seeing, unless tuning is altered.

My GTI was OBD-2, but it was also a '97, so less technology in it :laugh:

[YarisSedan]

http://www.bobistheoilguy.com/index.php?option=com_content&view=article&id=58&Itemid=66

[GeneW]

In simple terms, when engines were dumb, as with carburetors, they could be fooled by a HP filter, but new cars with OBD-II watching the airflow isn't going to let itself be fooled for long; it'll adjust to anything new that it's seeing, unless tuning is altered.

....not exactly. ECUs are not infinitely adaptable.

When you restrict air flow the computer will adjust mixture, valve and spark timing and other factors, but only up to a point. Once you constrain the airflow sufficiently the ECU will start to bounce close to soft and hard limits, and will eventually throw a trouble code light

Gene.

[1stToyota]

....not exactly. ECUs are not infinitely adaptable.

When you restrict air flow the computer will adjust mixture, valve and spark timing and other factors, but only up to a point. Once you constrain the airflow sufficiently the ECU will start to bounce close to soft and hard limits, and will eventually throw a trouble code light

Gene.

What I was getting at was that taking out a stock air filter and dropping in a hi-flow filter won't do what the box claims, but people will think it's really made a big difference in hp and fuel economy. I try not thinking about it now, but not too long ago a tool salesman that used to come around told me how he installed a K&N drop-in in his late model automatic Dodge truck, and instantly he noticed that it now gets sideways and lights up the rear tires at 55mph.

[Yaris Hilton]

Right. The reason all sorts of things get sold, accessories for cars, bikes, guns, sound systems, health and "wellness" items, etc. is that they create an expectation that they'll give a benefit, so the user perceives they've gained one and are happy with it.

[GeneW]

What I was getting at was that taking out a stock air filter and dropping in a hi-flow filter won't do what the box claims, but people will think it's really made a big difference in hp and fuel economy. I try not thinking about it now, but not too long ago a tool salesman that used to come around told me how he installed a K&N drop-in in his late model automatic Dodge truck, and instantly he noticed that it now gets sideways and lights up the rear tires at 55mph.

If you can't measure performance gains it's a pretty tough sell.

Gene

[1stToyota]

If you can't measure performance gains it's a pretty tough sell.

Gene

I think they sell plenty of them, and customers simply change habits (aka: driver's mod) easily enough to see what they're expecting...lead foot, wow that feels better now. Slow it down some, yeah, it improved the mpg just like the box said it would. :rolleyes:

[Yaris Hilton]

Exactly.

[1stToyota]

Right. The reason all sorts of things get sold, accessories for cars, bikes, guns, sound systems, health and "wellness" items, etc. is that they create an expectation that they'll give a benefit, so the user perceives they've gained one and are happy with it.

There's an old saying: Possession is 9/10ths of the law; there needs to be a new one...Perception is 9/10ths of the flaw! :tongue:

[deerebilt]

For me unless your racing use oem toyota air filters mine was only $15.00 from my local dealer. At 18k miles and 1 year old my filter didnt look dirty, performance was fine but after putting new oem filter my fuel mileage went up slightly. I trust Toyota's research and will use only Genuine Toyota oil and filters. My overall avg FE is 43.4 mpg.My Daily avg the last few days is 52 mpg.

[Kaotic Lazagna]

^ HOLY!!!!!!!!!!!! 52mpg!!!!!!!!!!!!??????????/