Does anyone know of any index that plots tire types as far as which ones will net better fuel economy?

By my thinking, a harder tire will have less friction and net better mpg. I've heard that stock tires offer the best ride with average mileage so as to test drive nicer but are usually the fastest wearing tire.

I'm currently running Pro-Comp A/T's but am looking towards Bridgestone duellers or Yokahama's for my next set.

 

hardes,skinnyer, and with less agressive tread will usuallly give better mileage.

 

I can tell you that going from a 235/85R16 E Steeltex Firestone (street tire) to a 285/75R16 Kumho MT (agressive mud tire) shot my economy to heck in a handbasket. I went from seeing 19.5/20 mpg to 15.5/16 and the lack of power in 6th gear was absolutly astonishing. Now that I have the mods I do, I don't notice it as much, but with a stock engine like it was at first, man, those big tires stink! Be careful. That is why I'd like to have 3:73's.