Looks like my tires are on there, but at a different size
They list the Sumitomo HTR 200 at 185/70R14, but mine are 195/50R15.
I wonder if they only listed that particular size but the basic premise of LRR applies to the whole model line? I would actually suspect that even though the 195 section would be worse that the 50 series sidewall would be stiffer and therefore actually have a lower RRC than the 70 sidewall.
What I found interesting was the very first factoid regarding 80% or more of fuel energy being lost to friction and other factors (aerodynamics, pumping losses, energy transfer, etc.)
80% - that's huge! So, we lose that much energy using gasoline or diesel, but all these new "enviro-friendly" fuels have even less potential energy so the wastage must soar to 90% and higher with propane, E85, natural gas, and other fuels.
I keep thinking that the extra energy loss, plus processing must offset most of the "cleanliness" of these new fuels.
The EPA should establish some sort of Fuel Economy rating for tires sort of like the UTOG ratings so consumers can tell which tire will be most efficient, and be able to calculate whether savings would justify buying a better tire.