The king of mpg tires are back from the dead! See:
http://ecomodder.com/forum/showthrea...e92-19126.html
Bridgestone Potenza RE92 P165/65R14 Low rolling resistance tires are finally being sold again:
http://tires2.costco.com/SKUorPartRe...&SearchBy=Item
You can pick up a set of 4 at Costco for $293.96, plus $14 installation package and $1 disposal fee per tire. The $70 off a set of 4 is included in this price, and ends May 4th. Otherwise they are $90.99 each.
These tires are regularly on sale, so i wouldn't worry about missing out on it. I'm just glad they're being sold again after being discontinued for about a year now.
While not necessarily the most economical tire as far as price and longevity are concerned. These tires have the lowest rolling resistance of any tire (regularly available in America in a standard wheel size.) They'll be sure to give you you're best tank, and deliver, in my case, what measly hp you have efficiently to the road.