Experiment I did in the past that worked WHY?
 

I have done many mods on SUVs over the year to increase mileage. Many my own ideas experiments, mainly dealing with air intake. I did countless 100% highway drives with little to no. Hange except one thing. At one time I did something stupid but don't worry the engine was nothing worth protecting.

Basically I put a pair of pantyhose on the air intake. Removing the filter I did this for 1 tank. I had never gotten gas mileage that good before or after. I experience a 30% increase I'm has mileage. Why?

I don't understand it. The vehicle was modern obdii injected mass airflow sensor o2 sensors. So the mixture of air to fuel should have been the same. Also if your vehicle requires a certain amount of power to maintain its speed an increase of possible power shouldn't change anything. Why did this work? It wasn't my driving style I have driven much better.

Measurement error. Placebo. A nice tailwind. Take your pick, but it wasn't the pantyhose.

Neither ^

go recreate it about 10 times.

report back

where they black or tan?

Were they... nah, better not go there.

What sort of engine was it, if it was a diesel, then I'd believe it, removing the restriction would improve economy considerably.
Do you still have the vehicle?, if so, as said above do it again.
Also, when was the filter changed before that & was it the right spec filter?

It was a gasoline land rover discovery. About a year later I drive into water over the windows offloading and got rid of it. air filter was new. As a matter of fact I tried replacing it with a highflow cone filter to no avail. But the difference with no restriction was incredible. It was no fluke. As I got way more miles to the tank than normal and I document all fuel consumption doing the math it came out to 22mpg from 16

I have a discovery. It is a pig. Maybe increasing the restriction would make thE engine think its under lesser load and not add so much gas

when you did this experiment, did any other variables change at the same time?
Did you go from a very small restrictive oem filter to no restriction, allowing the big piggy engine to operate with less vacuum? Do you have a vacuum gauge to measure changes being made?
Did your panty hose on the end of a hose drastically change the location air was being pulled from, ie from the relatively cold outside to the relatively warm inside, near an exhaust header or similar?