Well, I'll throw my hat in the ring. With my 2009 I would average 40-41 at back road speeds of 45-55 mph. Converted to CSC Cobra XL in Jan 21, I average 35-35 1/2 at those same speeds. I run a Cobra Trike tire up front at 41psi and the CSC stock Ohtsu tires at 20 psi. Ride is good and I'm satisfied with mileage. Ohtsu tires are wearing like iron. Cobra trike tire is about ready for replacement. Didn't write down replacement mileage but I'm guessing I'll get about 15k or so out of it... Have it's replacement sitting in the garage waiting for summer...
Les