[Big Dave]

I suspect the RMA does have a “gag order” on low RR tires. The reason is simple: Product liability.

If the average Joe knew which tores had the lowest RR, in times of high fuel costs, too many unskilled people would buy low RR (low traction) tires and have accidents and sue the tire manufacturers because they didn’t have warnings against morons driving low RR tires.

Most people here know the trade-offs made to get low rolling resistance and are not lead-foot drivers anyway.

Indeed tire manufacturers know the RR of their tires and they share that data with car manufacturers.

One good surrogate parameter for low RR: Noise. A quiet tire will tend to be one with low RR. Makes sense. Noise requires energy and where would that noise energy come from?