[MetroMPG]

Welcome, and congrats on your early improvements!

Also put on the to-do list: get a "game gauge" (ScanGauge, Ultra-gauge or equivalent). Don't underestimate the positive effect of instant & resettable trip average on your motivation & skills.

You can also boost your efficiency further with some aero mods, considering all your highway driving. Another 5% gain with a couple of hours tinkering isn't much of a stretch.