Now for the results!
Right before starting the first mods, I did some testing to get a base score. My primary goal is to improve MPG at 75mph, so that's what I tested at.
My procedure: I live right by an interstage highway with a gas station right at the exit, so I filled up at that gas station and reset the trip meter. Drove 7 miles west, exited and turned around and drove the 7 miles back. Then I filled up at the same gas station and recorded the gas used and miles driven. I used the cruise control to keep it at exactly 75mph.
For the base score, I recorded 13.9 miles and 0.93 gallons. Which is 14.9 mpg.
Today I did it again with all the mods performed (similar weather but not exactly the same of course, but nothing else changed to the vehicle like weight or tire pressure).
I got 13.8 miles, and 0.81 gallons. That's 17mpg.
14% better!!
Yes I realize that it I should have done the test like three times for trip A and trip B but, that would have taken all day.
So for my up coming road trip to Portland, I'll be driving around 4,400 miles. Using the
https://www.fueleconomy.gov/trip/ tool, it says I'll save $70. Which is great and all but I didn't really do these mods to save money. I hate burning more fuel than necessary and I saw an opportunity to improve something and I went for it.