Just a quick update: another fillup since installing the smaller mirrors. And this was my best fillup to date! It came out to 63.45 mpg! That's 3 fillups since installing the motorcycle mirrors, with an average of 62 mpg. The 3-tank average before installing the mirrors was 60.8 mpg. So the mirrors seem to be making a difference. So I guess I won't be reinstalling the stock mirrors. Next up will be the pizza pans.
That said, driving conditions can have a huge effect on fuel economy. Over the course of several hundred miles, that can add up. And it can wash out any gains (or losses) from modifying the car. So I wouldn't take these mpg results as gospel.
I'm thinking of doing a coast-down test. That might provide more conclusive data. But coast-down testing each individual mod will be very tedious. And to be blunt, I just don't have time for that. So I would like to do a "stock vs eco-modded" test. For example, I would test the car completely stock, then install some eco-mods (grille block, mini-mirrors, wheel covers) and compare the results. At the very least, we should be able to see if eco-modding is worthwhile.
Let me know what you think about that.
And last but not least, my youtube channel reached 1000 subs! To celebrate, I'm doing a giveaway. If you want to win some free swag, check out the video below.