I have a almost stock 89lx..AOD with catback..new alt. tuneup.. rite now my fuel gauge is not working..so i have been working on my tripmeter.. what would be a safe # i should be looking for.. i was figuring maybe 15mpgcity/highway driving...and i think there is 15.4 or something gallons in the tank full.. so roughly i should fill up every 200 does that sound good as a ballpark figure.. i do have a lead foot in occasions so maybe a little less?