It's only 2 data points, but I'll eventually have a nice array of data on the effectiveness of LRR tires. I purchased my 2007 Prius used and the previous owner had put on new (but regular) tires. The Primewell 830's were not great, but I kept them for 2 years. I just upgraded to the Bridgestone Ecopia EP422. After just 2 tanks (not even broken in yet) I'm seeing a 4 mpg improvement (7.5%). The chart below has 3 nodes - all driven by me with essentially the same route: 2004 Prius with Goodyear Integrity LRR Tires (and Integrity replacement tires) 2007 Prius â€“ bought car used just after new Primewell 830 (non LRR) tires had been installed. 2007 Prius LRR - I recently replaced the Primewellâ€™s with Bridgestone Ecopia EP422. Yes, it is just two data points, but at the same average temperature the two red squares are running well above the red diamonds. More data to come.