Does dirty fuel filter cause bad economy? - Fuel Economy, Hypermiling, EcoModding News and Forum

Z2TT · 01-25-2010, 09:46 AM

Hello.

I have read on various forums that people have experienced better fuel economy after changing their fuel filters.

I'm wondering, how can a dirty fuel filter cause the vehicle to use more fuel?
wouldn't it use less?

Thanks.

MadisonMPG · 01-25-2010, 09:48 AM

It can cause you to have worse, but most of the time it doesn't. (at least in my case)

Z2TT · 01-25-2010, 10:04 AM

Thanks,

I'm wondering though, what is the technical explanation behind it causing bad fuel economy.

Johnny Mullet · 01-25-2010, 10:39 AM

If the filter is clogged, it won't run. If it's restricted, it simply makes the pump work harder.

Peter7307 · 01-25-2010, 05:19 PM

Quote:

Originally Posted by Z2TT

Hello.

I have read on various forums that people have experienced better fuel economy after changing their fuel filters.

I'm wondering, how can a dirty fuel filter cause the vehicle to use more fuel?
wouldn't it use less?

Thanks.

Z2TT,
A dirty fuel filter makes no difference to economy but it usually restricts the upper rev limit simply due to lack of flow.

Totally blocked the filter simply stops the engine since fuel can't get through.

Pete.

Dave's Civic Duty · 01-25-2010, 05:35 PM

By trying to keep the engine running, the natural impulse is to add more throttle. So to make up for the restriction we try to add more fuel by pumping the accel pedal. So for instance instead of having the engine cruise at let's say 1500 RPM we overcompensate & the result is a fluctuation in overall engine speed 1250 to 1750 to 1400 to 1600, just trying to keep a steady 1500.

Dave

Frank Lee · 01-25-2010, 06:18 PM

If only K&N made fuel filters- think of the power and economy!!!

Gasoline Fumes · 01-26-2010, 09:18 AM

I thought the dirty air filter thing was from back when cars were carbureted. Doesn't a restriction in airflow act as a choke, making the engine run rich?

Dave's Civic Duty · 01-26-2010, 09:48 AM

Frank Lee, what is your reasoning behind the K&N fuel filter. I run a K&N air for my truck, I noticed a difference right away. Is it an ultra low restriction gas filter?

Dave

Old Tele man · 01-26-2010, 10:10 AM

Quote:

Originally Posted by Frank Lee

If only K&N made fuel filters- think of the power and economy!!!

...DANGER, Will Robinson, DANGER!

...if you use both a K&N air filter and a K&N gas filter, you'll save so much gasoline that it will backup and overflow the gas tank capacity, causing hydrocarbon air pollution and a fire danger (wink,wink)!!!