Some fuel economy data before and after a drop-in K&N filter and Bosch +2 Platinum plugs

I had a bunch of mpg data from a vehicle I just sold, figured I see if I could answer a few questions with it. There is tons written about whether drop-in K&N filters do 1) nothing, 2) increase mpg slightly, or 3) actually decrease mpg.

In addition to the K&N filter, I also put in new Bosch platinum +2 plugs at the same time.

Both are marketed as potentially increasing fuel economy.

I put in a K&N drop-in filter and plugs about 6 months after I started recording my vehicles fuel economy regularly, so the following are data for that "before" period, and the "after" period is the same ~6 months the following year. (I installed them in May so I didn't want to confound the "after" period with MPG increase expected in summer vs. winter).



The vehicle is a 2001 2.4l 2wd Tacoma regular cab. Stock tires, height.

Obviously this isn't an experiment, just some real-life data which suggest to me no evidence that either modification did anything to detectably increase mpg. This is probably not a surprise to a lot of people

 

Oh the suspense!

 

Oops, I hit submit before I was done -- Edited the original post