MPG experiment....1976 Dart Lite

Same station as past 4 fillups. Same procedure, fill on low speed, until it shuts off, and then one more slow until it quits.

206 miles on 10.5 gallons...19.61 plus the conversion for the tire diameter of 3% = 20.19 which is best so far.

I had a test running by accident. A while back I took off the air cleaner, to mess with the accelerator pump linkage, and clear out vacuum lines. I forgot to put the air cleaner back on. I knew it was there, but it got lost in the shuffle with the twins coming, and I just plain forgot. If I reference this tank as #4.
Tank #4 was 20.19 mpg
Tank #3 was 18.16 mpg
Tank #2 was 17.28 mpg
Tank #1 was 20.18 mpg

So, the 2 tanks between previous best of 20.18 and now best of 20.19 were down, 11% to 15%, and these were the tanks when the stock air cleaner with parts store paper filter was off.

So, my Sheer-Luck deduction tells me that the air cleaner provides better mileage, then an open carb.
Feel free to call me a rocket scientist :toothy10:
I presume it is for 2 reasons, the velocity inside the tube, and the contour of the base of the air cleaner, streamlining air entering the carb.