[Sven7]

Exactly. That's easily 800 RPM over what, a couple hours? Slowing down 10mph on a 2 hour drive will only cost you 20 minutes. Going fast is not worth the gas.

How much are you using P&G and EOC? Especially in the city, when you're not accelerating, pop it into neutral and coast. It cuts your revs in half easily, and on longer coasts you can EOC with effectively infinity MPG.

Also, block up that top grille! The top one will get you better gains than the bottom because you want the air to go over the top of the car easily. Maybe think of getting an OEM front lip.

I'd skip all the trans mods and whatnot because they aren't going to save you much money considering the cost of the mods. I'm driving what's essentially a Mazda MX6 and consistently getting 38MPG and 400 miles with a little effort. It's mechanically stock, but with a few aero mods. Have you removed the rear seats, or do you need those for the little one(s)?

Pop that baby out of gear and save some MPG's.