Tire pressure raised to 43psi has yielded 41.48mpg. 378.8 miles out of 9.133 gallons
I will say there were a couple drives to and from work where increased air temps sure didn't hurt either. But then there were a couple trips to the local grocery store too so *shrug* Target speed has largely stayed at 55mph. The exception being going down hill I'd leave the throttle where it was and pickup speed to carry into the next hill, unless there wasn't one then I'd lift to maintain speed. Most shifting has stayed between 2500-2750rpm staying in as high a year as I can and getting there as soon as I can realistically for the given scenario of the moment.
I have collected 1 or two pieces of sizeable scrap sheet metal (aluminum) that's thin. So I'll start on aero soon. First order of business will be to repair that part under the bumper, and adjust the drivers side fender as it's high for some reason.
So long as temperatures are reasonable this weekend I'll probably pull it into the shop and get under it and start developing a plan for how I'm going to attach the under tray and where.
Eta: I did for sure notice lean burn engaging the other day on the drive home, I felt a weird reduction in power as if someone suddenly retarded the ignition timing a lot. So lean burn is working.