If you worry about fuel economy you bought the wrong bike, when ridden hard they're around 3 to 4 times more expensive to run (oil inc) than a 400 diesel and that's before you cost in a front barrel or two
I did Rockingham National on my first RVF400 which was at the time totally standard on less than a tankfull (the tank is smaller than an NSR too)... It didn't even get onto reserve.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread