Replacing Fuel Filters Sooner Increases MPGs? How so?

Clearly this is false. Dark color trucks get better fuel mileage because the sun makes them warmer than light color trucks which makes the air molecules thinner making the truck glide through the air easier.

Seriously though, I change fuel filters every 12k miles when I do an oil change because I fuel at cheapo sketchy gas stations.

 

What kind of service intervals were they talking about in class?

 

The only way to know whats going on with the fuel filters is to run a fuel pressure gauge, plumbed after the filters. Once you start losing fuel pressure you know the filters need changing. I suppose if plumbed after the fuel pump but before the secondary filter, pressure would increase once the filters have passed service life. But the first way seems better.

I once read about a guy who tested this theory and went over 60k miles before his filters were limiting fuel supply. Changing them at oil change time is probably more than adequate.

I just recently installed an autometer 0-100psi gague in my truck with detroit 60 engine. unfortunutely im hitting 100psi at only 1400rpm. I should have gone with a teltek 0-300psi gague.

 

New fuel filters didn’t cause that.
Other unknown variables most certainly were the cause.

 

The "other" way to know is to have a fuel restriction guage . Some trucks have them. Just shows restriction on the primary filter. If you happen to get dirty fuel, or in cold weather you can watch how things are going.