I have never seen a spec for rolling resistance. First tires would come to mind in that spec. Then of course other hardware plays a part. Since tires contribute the most to rolling resistance the spec would seem very important in regards to fuel savings etc. This thread was generated because of notable difference between my new tires compared to the old tires. First I use nitrogen inflation with both sets of tires that is said to cut down on resistance. The car like tires that came with my truck seem to have a harder compound less tread and far less aggressive in design. The tire weighed slightly less then the new ones. The size is identical so there is no comparison there. I have lost at least three miles per gallon with the new tires. This was unforeseen. I don’t blame this to anyone but a rolling resistance spec would have been useful in regards to cost over the life of the tires. Reference: BFG: Rugged Trail vs. All terrain TA KO 265-70-16 I knew there might be a slight difference in theory but with no spec to show the difference I had no idea just how much of a difference. The air pressure is set at 35.5 PSI but is allow to max at 65 PSI. Anything over 38 PSI and the tires ride too hard and I don’t want to cause center ware.

 

http://ecomodder.com/forum/tool-aero...resistance.php

 

I considered this for my VW TDI which is my economy car, it gives me a steady 50mpg when I don't need the A/C. Never really thought about it for the truck, but a 3mpg hit is huge.

Anyway, I got a lot of info here in my tire selection here - http://www.consumerreports.org/cro/cars/tires/index.htm maybe they list your tires for comparison.