First things first, this has nothing to do with gas mileage. My 2004 Titan only get 280-300 miles per tank when my low fuel light goes on. I only fill up approx. 20-21 gallons leaving 7-8 unused gallons. My buddy fills up with 25-26 gallons when his light goes on. A service tech told me it may be a bad sending unit which could cause poor fuel pressure. Does this sound right? Could this effect anything other than having to fill up more often. I have 95000+ miles and this wouldn't be covered by Nissan and I wouldn't pay to fix it if it doesn't effect engine performance. Any guidance is appreciated.