The high milage capability of the full tank of the TCH is simply a bonus. If you want to fill up at 400 miles DO IT!

If you look at my milage data you'll see some small tanks. I've intentionally filled up on tanks between trips and local driving just so the interested people can see the differences. It's difficult to really remember the difference in city / rural and highway if you have it all in one tank. I'll eventually stop doing this but for now the station is near my house and it's no problem. It does seem weird though after having 300 miles on a tank (when I used to have to fill up) it now only takes 7 to 8 gallons to fill up for that same distance.

However that's how I know I'm saving. If I put 600 miles on a tank then the cost is about the same as I used to have per tank (I just had more than double the milage). But now I can fill up for less than $25 and in my other two vehicles the same milage was anywhere from $45 to $65.