I've seen a few different favorite ways to fill.

I fill slowly and stop at first click.
That way the fuel isn't right up to the top of the neck.
Not much splashing in tank when filling.

I rather fill in the a.m. when the gas is cool. More dense. It expands significantly when it warms up later in the day. Commercial fuel distributors measure the fuel temperature and adjust price accordingly. We consumers get um, s*r*w*d paying full rate always.

As long as you're consistent. Nice if you can use the same pump or at least the same station every time.

I say do the free stuff first...techniques will get you more mileage free. Taller tires will bump your gear ratio a bit and might help...but use up what you have already. Some kind of "guage or readout" would help perfect your hypermiling techniques. Higher psi is also another freebe...remove any excess weight...synthetic oil with a lighter weight...clean air filter. See what you end up with.

Welcome to GS's.org! Did someone say ride a scooter? That would be pretty cool to see a pizza delivery guy in a scooter. None in La Crosse, WI for sure. The only one I've seen delivering pizzas was on Spiderman II (?). With you driving under 60mph you should be able to consistently get great FE. Keep up the good work and let us know if you do swamp in the CX tranny.:D