LRR Tires, questions

Here's what I am aware of when a tire is said to be LRR. From the weight of the vehicle the bottom of the tire is flattened some which is where it comes on to contact with the road. So the tire is not perfectly round. For ideal low rolling resistence you'd want a perfect circle, but then that brings in the saftey issues of loosing control too easily. LRR tires use a extra strength side wall so they don't deform at the bottom as much. They can also incorporate different compounds in the tread which make the tire easier to turn. Soft rubber takes more power to spin than hard rubber.

Unfortunately there is really no rating of LRR. From what I've seen the Potenza is going to be the lowest rolling resistance of any tire your going to find. As I've mentioned the Goodyear Integrity is close behind it. Generally if you look for reviews on tires and find ones that have bad reviews as far as traction it's a hint that they are LRR. Also if you look on the manufacturers page sometimes it will say something like designed for better fuel efficiency.

Like Rick Reece has posted before he tried some skinny 155 (was it) tires on his Insight that were not LRR and mileage was about the same or actually took a hit if I recall correctly.

Yeah, their engineers probably get to consult with tire manufacturer engineers and then buy a few different types and experiment. One of my other goodies I have are some slides from the original GM EV1 concept car, the Impact. One picture shows the wheel and tire. Goodyear specially made them a set of LRR tires that could be inflated to 65 psi. That car had more range than the final production car did even.

Here are a few other LRR tires I know of:
Michelin Proxima EV1 tire, no longer made
Tigerpaw something, used on the EV trucks, no longer made
I think Nokian makes a LRR tire as well, kind of hard to get though.
Honda had some special LRR tire on their EV+ too, but I don't have a clue what they were.
Now I'm kind of curious as to what kind of tire is found on the production RAV4 EV's.
Dunlop A20, used on Civic Hybrid

If you look on the electric vehicle discussion list a while back a person knew someone who owned a tire shop so he rigged up a device to push his car with a constant force so they mounted up a bunch of different tires and found the Goodyear Integrity was the lowest RR of the group.