Replacing air filters

[desura]

Right now I'm driving a Subaru Outback and I'm trying to think of ways to improve its fuel economy. I read somwhere that replacing air filters more regularly is a good cheap way to improve fuel economy, in addition to like keeping tires inflated and oil changed.

So this isn't too difficult, right? Just get this

http://www.rakuten.com/prod/2005-2009-subaru-outback-air-filter-full-w0133-1635760/236040567.html

find some instructions on the net, implement, done, right?

 

[LTC8K6]

I don't think replacing the air filter more often than the mfg says to would be of any benefit on modern vehicles.

 

[vshah]

air filter is pretty much the easiest thing to replace. find the air intake, a large tube going into the engine. follow it back to a large black box. flip some clips around the edge of the box to free the top half from the bottom half. open it up and replace the filter. close it up and snap clips back on.

the above will work for probably 80% of cars out there

 

[rommelrommel]

It's easy but no real benefit to replacing more unless you drive in dusty conditions a lot. Even then you can shake/knock out a lot of the crap and keep using most of the time.

Tires inflated, low rolling resistance tires help a bit, synthetic oil can have some tiny gains. Spark plugs on certain vehicles as they tend to foul.

Really most of your gain comes from gas/brake usage. Slow starts, anticipating stops to keep rolling (ie: don't blast up on a red light just to some to a full stop, coast up to it and let it turn green before you get to it) and sadly... speeding... cut it out if you care about economy that much. Especially highway speeding, cruising about 60-65 isn't too bad but 70-80-90 use way more fuel due to drag. Oh, and also taking off unused roof racks and ESPECIALLY those car topper things if you have one.

 

[nerp]

Nothing you can do other than keeping the gar in good repair and driving conservatively. You just have to accept the fact you own a Subuaru. My wife has a 2011 Forester. We love the vehicle, hate the milage. Pretty sad that my 300 HP sedan which weighs nearly 2 tons destroys it in the fuel economy department.

 

[Jimzz]

Most air filters are changed to often. They can last 30k and sometimes up to and over 60k. Just take them out and dust them off every oil change and they will last a good long time.

As said check your tire pressure. Seems most cars I see the pressure is low. That will cause uneven tire wear and use more gas.

 

[Raizinman]

A quick and simple test to determine if you have enough air filter flow or of if your air filter is clogged is to install a port between the air filter and throttle body. Basically, get a vacuum gauge ($12) and install in the plastic tubing anywhere between air filter and throttle body. You can temporarily run the rubber hose out the back of the hood through the driver’s window. When the test is over, remove the vacuum gauge and cap the hole.

When driving the car, the vacuum gauge should never show vacuum; otherwise you have most likely a clogged air filter. Also important to do this test at (WOT) wide open throttle, which uses the most air flow. If you use this test, you will find that you can usually go a very very very long time before it is necessary to change your air filter.

 

[Throckmorton]

A quick and simple test to determine if you have enough air filter flow or of if your air filter is clogged is to install a port between the air filter and throttle body. Basically, get a vacuum gauge ($12) and install in the plastic tubing anywhere between air filter and throttle body. You can temporarily run the rubber hose out the back of the hood through the driver’s window. When the test is over, remove the vacuum gauge and cap the hole.

When driving the car, the vacuum gauge should never show vacuum; otherwise you have most likely a clogged air filter. Also important to do this test at (WOT) wide open throttle, which uses the most air flow. If you use this test, you will find that you can usually go a very very very long time before it is necessary to change your air filter.

Or you can just look at the filter and replace it if it's dirty

 

[SpatiallyAware]

How many miles on the car?

How long since last tune-up including fuel filter?

 

[CraigRT]

I don't think replacing the air filter more often than the mfg says to would be of any benefit on modern vehicles.

Pretty much this.
I look at mine every second oil change and its hardly dirtier than the last time..
They just do not require the change frequency some people are doing. My car is on its second at 60K miles.

 

[railer]

Or you can just look at the filter and replace it if it's dirty

Raizinman's test would actually tell you if your filter was not allowing through the air supply your engine needs, which probably seldom happens. Whereas visually inspecting for a dirty condition tells you next to nothing.

 

[SpatiallyAware]

For all you know there's a micro tear in a pleat. It happens. And it would 'pass' the gauge test.


I replace mine every couple of years, needed or not.

 

[Raizinman]

The only times I have seen air filters tear or such is from people taking them out and in all the time. If you take your car to a quicky oil change place, they are required to remove the filter and wave it in your face and try and convince you that you need to replace it for $50 or more. If you change your oil every 5,000 miles and your air filter can last 50,000 miles, that means Jiffy Lube has removed this air filter 10 times waving it in front of your face. Heck, they probably tore a pleat on the second or third reinstall. Never let these quicky oil change places play with any other parts of your car. Heck, they can rarely change the oil correctly. I'm on retainer with many of the quicky lube shops and have seen many a nightmare.

For all you know there's a micro tear in a pleat. It happens. And it would 'pass' the gauge test.


I replace mine every couple of years, needed or not.

 

[jagec]

Tires inflated

To sidewall, of course.

 

[AustinInDallas]

you can do every "trick" in the book, but only way to get real gains is driving habbits

 

[Mxylplyx]

A quick and simple test to determine if you have enough air filter flow or of if your air filter is clogged is to install a port between the air filter and throttle body. Basically, get a vacuum gauge ($12) and install in the plastic tubing anywhere between air filter and throttle body. You can temporarily run the rubber hose out the back of the hood through the driver’s window. When the test is over, remove the vacuum gauge and cap the hole.

When driving the car, the vacuum gauge should never show vacuum; otherwise you have most likely a clogged air filter. Also important to do this test at (WOT) wide open throttle, which uses the most air flow. If you use this test, you will find that you can usually go a very very very long time before it is necessary to change your air filter.

This. I don't monitor the mileage on my Honda filter, as I just inspect it a few times a year and replace when needed. I think my last filter lasted 2-3 years before it looked dirty enough to warrant replacement. A quick oil change place will obviously have a different opinion on what is dirty since they are trying to make an easy buck.