My '02 4Runner just got a new fuel filter (at 113K miles) and it has noticeably improved the mpg. Back when the truck had 84K miles, I replaced the spark plugs and the air/fuel ratio sensor. Shortly after, noticed the truck wasn't getting as good mpg as it was before. It didn't make any sense. Now that it has a new filter, the mpg is back up to where it used to be. Pretty cool. I calculate the mpg by filling up the tank and then recording the miles driven till the fuel indicator arm is right at the 1st line up from Empty. The truck is getting 35 more miles per fill-up (like it used to). I just wanted to let you all know in case you are wondering if you should replace that "Lifetime" fuel filter. From my experience, I think I'll replace the fuel filter every 75K miles. Also, the old fuel filter had some very muddy looking gas when I drained it. The new fuel filter was about $27 bucks from the dealer (www.championtoyotaparts.com). Hope that helps you all out.

 

The gauge is very inaccurate. You need to calculate MPG the right way. Fill up. Reset trip A in the odo. Run the tank down, till the light come one etc.. Fill up again, Divide number of miles driven by number of gallons the tank took to fill back up. And don't top off. That throws off the readings.

 

fill up from the same pump, and stop at the first click

fill up again from same pump, parked in same direction, stop at first click

calculate miles per gallon

do this a third time, same pump, same direction, one click,

this will get you the most accurate mpg's

my 4runner varies from 14.4 mpg to 22.5 mpg depending on what I am
doing to empty the tank.

wheeling in 4lo I get maybe 5-6 mpg or even less depending on how bony it is

 

If you have an 01 or 02' when you fill up, go till it clicks ONCE and STOP. If you don't you will ruin the vapor canister in the back and they are almost $500 new.

 

Good thing I have a 2000. I had to pull the gas tank on another car and I didn't have anywhere to put the gas except my 4runner. I filled it till it was coming out the filler tube!

 

I'm trying to figure out how replacing the fuel filter would affect gas mileage?

 

Maybe when the fuel filter is getting clogged the ecu has to make some adjustments to the air fuel ratio or something that is less ideal than if all of the fuel is coming through the filter when its clean creating more pressure in the line between the filter and the intake??

 

could cause a lean condition, a lean running engine uses more fuel as the engine isnt making as much power, therefore has to work harder.

 

My filter was very dirty at 90K when I replaced it. I think the brown residue that sits in there contaminates the fuel. I get about 0.5 - 1 mpg better after replacing it.

 

It doesn't.

If there are serious flow problems inside the filter, you would know it when running the engine fast and under load. If it isn't sputtering and bucking going up a hill, then it flows more than enough under normal driving condition.

 

And to think that Toyota says it's a "life time" fuel filter. I've done enough fuel pumps on GMs to know better than that.

 

just had mine done recently and noticed significantly better throttle response at all speeds. The pep is back!


The brown muck that came out of mine has convinced me to do this about every 50K miles or so. I do my best to always buy "quality gas" like Shell or another major brand- but if you have ever seen a fuel tank when pulled out of the ground you get a quick appreciation for the crap floating around inside your own smaller tank.

 

Theres not many parts in the fuel system that last a life time.... except maybe the gas tank...

 

I had so much fun changing mine last week that I did it twice!! (installed backwards the first time...)

My old one had some serious brown specks/grit when I blew it out and I know it had been in use for at least 56k, def not original though.

I was also overdue on cleaning my air filter and after having done both she's much peppier again - and not as hesitant on cold shifting either. Air filter was severely nasty...

 

totally! when i got my F150, with the a/c on i got about 10mpg on the highway!! now, after new spark plugs, new o2 sensors, gotts mod on the intake (basically a cheapo more effective cold air intake setup) new fuel filter, with the a/c off im getting about 21 on the highway. with the a/c on it drops to about 16.
oh, and zeik... id rather do it on the 3.4 than on the 22re... at least yours doesnt involve removing the EFI manifold.... DOH!

 

Hell, I prob would've left it on backwards if it was under the manifold and I didn't notice until after re-assembly!