I have about 500 miles on my XIED's now and 2 tanks of fuel. 1600 miles on the SERK. My MPG before the XIED's was averaging 43MPG. With the XIED's my last two tanks were 47MPH and 49MPH. I don't know if it's coincidence to the 1000 service and the bike breaking in, or the result of the XIED's. It's somewhat counter-intuitive that your MPG would go up with the XIED's increasing the fuel to air ratio, especailly that significantly. Mind you, I'm not complaining. As for heat, I don't have a IR thermometer so I'm having to use my 53 year old buttmometer. It says the heat is slightly lower, but still fairly hot. My refereing point is my old '02 stock 88TC RK. The SERK is still hot enough that I'm considering adding one of those heat deflectors that attach below the seat. I just really hate how they look. They also look like they may interfer and bite into your inner thighs. Anyone with experience on those sheilds and whether or not they are worth the money? Do they hit your inner leg?