I ran the 16-inch OEM Ecopias and replacement MXM4 Michelins on the 2011 at 44 psi. Handling, wear rate, wet traction, and range were all improved over the factory-recommended 36 psi. I ran the OEM 17-inch Michelin Energy Savers on the 2015 at 44 psi, but tried the entire range from 36 to 44 in an attempt to get decent traction and handling. They were bald at 28k miles and I consider them the worst tires I have ever owned because wet traction was really poor. I replaced them with Continental sport/touring tires and gladly accept the 15% range reduction in return for MUCH better handling, wet traction, and dry traction. Also, they show very little wear after 10k miles.
If you really need the best range, Ecopias inflated to 44 psi have good wet traction and decent handling. There is an incredible difference in handling, how the car drives in cross winds, and especially wet traction between 36 psi and 44 psi with the Ecopias. I think the LEAF is too heavy for Ecopias inflated to only 36 psi.