Coming off a WR250 (where I got 60 mpg) I'm astonished at the mileage on the 450. Looks like I should expect 35 to 40 mpg on average. Went on reserve at 51 miles yesterday with a stock tank. Several times a year I run multi day back country trips where it is not uncommon to go over 100 miles between fuel stops. Assuming 40 mpg I would be pushing the limits on a 3.2 gallon tank. I've seen the Acerbis 6.6 gallon tank and am thinking I could use it for trips only. Do any of you have experience with this (or a similar) tank? Other options?