[MetroMPG]

Blocking excessive grille opening will have a bigger effect than closing up seams. I'm sure you know you need a way to monitor coolant temps to ensure you don't go too far for your typical driving loads.

---

Does your car have a "manual" shift mode?

I've often found that you can get an automatic to upshift SOONER using manual mode than the default automatic programming permits. That will help as well.