Thats what I do, reset both the mpg and trip A computer on fill up, then multiply the average mpg by 17.5 then subtract what it says on trip A = miles left  
  
Of course it would be much handier to print out the guide on fixing the issue and perform it, but i'm way too lazy for that right now  
  
I cant do that because my computer tells me I am averaging 48 in town and 64-72 on a run!!! 
Ever since having the super charger installed!  
It's one thing after the next at the moment:( sob sob