Nighthawk, I have a 1300C with Clayton mod pipes, K&N filter, no other mods. I drove solo to Daytona and I got 50-52 mpg highway (minimum speed 70 mph), 40-42 city. I have never gotten below 40 mpg no matter what I do. Riding 2 up on th highway I get 46 mpg. I'm also a big guy, 240 lbs.