I'd say see about getting the Michelin HydroEdge for a good rear tire. One of the best RR tires out there, plus it's unidirectional and an excellent tire all around (90k warrenty)
Wait. There is a new Hydroedge coming soon - Green X version. It'll be better RR. I couldn't wait, so the Odyssey got a set of new Goodyear Fuel Max tires instead. So far they are at least comparable to the old Symmetry's, while still being new tires. Quieter, too.
All the HydroEdges are Green X tires, at least any recent ones. I know the one's we've had on the shelves at Sears for the past six months are the Green X variety.
I average 45 mpg most of the time. the key is to keep her under 3,000 rpm. since most of my riding is mountain roads, and keep it under 60 mph. 55 mph is 2500 rpm. the valk has so much bottom end torque, you can cruise through town in 5th gear, and it will pull strongly right off idle, I seldom have a need to rev it over 3,000 rpm.if you have a need for speed however, you will pay for it at the pump.