I apologise if this has been covered already but I've not been through all twelve pages - but aren't many of the tires listed in the first post actually quite wide ones? Surely the biggest rolling resistance benefit is from finding narrower tires.
Obviously that's not often possible the further you go up in rim diameter, but for the smaller tires there must be narrower options? The narrowest listed for 15" wheels there are 195 section, which is what my Miata has on aftermarket wheels... and I consider those quite wide for the size of car... I'm damn sure there must be LRR tires in narrower widths than that for 15" rims!
The original Insight had 165/65 R14 tires, Bridgestone Potenza RE92s. I'd expect those are fairly LRR and I can't believe there aren't competitors for other brands in that size or similar widths.
This isn't criticism... more an observation on what's otherwise a very comprehensive list
