I have never landed an airliner with less than 45 minutes fuel because I didn't let dispatch do it to me. They tried several times but did my own calculations and ignored their plan. I have posted a couple of examples so won't bore you again. They are sitting in a dispatch office and you are in an aircraft with limited fuel so do what you have to do and screw them in their comfy chair. Also, if you are the FO, don't let the captain be stupid because he believes them. Had to deal with that once too going into SJC with all airports below minimums and he wanted to shoot a minimums approach with everybody diverting to SMF. I talked him into diverting and we got there first with a gate and SJC went below minimums so we would have been in serious trouble.