Air filter experiment is showing positive results.

M

Maleficio

Member
Car
2005 FX45 rwd
Name
Allen
Today I began an air filter experiment on my 05 45.

I needed to pull and clean my K&N air filter so I decided to remove the entire air box and front intake tube and zip tie another filter to the intake minus the air box and see what would happen.

Before zip tie-ing the temporary filter I cleaned the MAF with CRC MAF cleaner then installed the filter securing it with zip ties.

By the way, I clean my MAF regularly so I don't think this cleaning played into the efficiency increase.

After a 20 mile trip around town and on the interstate the gas mileage went from the normal 16 to 19.2.

I'm going to leave this setup intact and monitor mileage over the next week or so.

In the past mileage reading would be all over the place at first but would always settle at 16 after about five miles of driving.

I was surprised to see it settle at 19.2 this morning.

If after a week of driving mileage returns to 16 I will reinstall the air box and intake runner.

If mileage settles at higher than, say 17, then I will modify my air box by cutting away everything but the filter frame so I can use the clips to secure the filter instead of zip ties.

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My old 03 FX45 average around 17.5 mpg with mix highway and local.
 
Would it not gather more dust/water/etc since its so exposed? Will you have to replace it more often? If yes, it might offset your fuel saving.
 
nima said:
Would it not gather more dust/water/etc since its so exposed? Will you have to replace it more often? If yes, it might offset your fuel saving.
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It's possible. Luckily I've already got two cleanable/reusable air filters. The cool thing about this setup is ease of filter replacement; no air box to deal with.
 
Maleficio said:
It's possible. Luckily I've already got two cleanable/reusable air filters. The cool thing about this setup is ease of filter replacement; no air box to deal with.
Click to expand...

I wonder how much of a difference it'll make on my car. I don't drive that much anymore at least so the savings would be minimal. Cool idea though!
 
I think this might be fine right now, but as the weather heats up that area will be very warm with the engine heat. I suspect that it won't work very well come July.
 
Mileage settled at 17. This setup yielded one extra mile per gallon but it negatively affected driving at speed from the lack of ram air provided by the factory setup.

I reinstalled the factory intake with a freshly cleaned/oil K&N air filter.
 
I didn't like how the FX45 performed at speed because of the lack of ram-air the factory intake provides so I reinstalled the entire intake assembly along with the freshly cleaned/oiled K&N air filter.

With just the air filter ziptied to the MAF I was getting 17 mpg, one up from 16 I was getting before this experiment.

Now, with everything back together along with cleaning the MAF I'm getting 18 mpg.

Weird.

Car's running smooth and strong with two extra mpg.
 
It's your driving habits changing or just luck. You made a hot air intake that if anything would reduce mpg. My car came without a factory intake so I had to modify the hot air Intake to get cooler air.
Routed it underneath the headlight and did a fog light delete with a 45* elbow to get fresh air right to the filter. Have a reflective cover on the intake as well as a custom shroud. She runs great and IAT are almost always ambient air temp when driving.
 
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