Hi, I recently filled my car up twice since I replaced my upper intake manifold @ 247K. Once @ 206 miles it took 7.3 gallons of gas, giving me 28.21 MPG!!! and the second time @ 371 miles it took 13.7 gallons of gas, giving me 27.08 MPG. I have to calculate how much fuel I am using in my car by the trip odometer because my sending unit is bad and my guage reads full all the time. My vehicle has 249K now and for the past two months I average about 99-115 miles a day highway and in town driving. My gas mileage has ranged from 23 to 28 miles to the gallon. If I replace my sending unit will that affect, or improve my gas mileage :?:



1997 Bonneville SE (3800 Series II L36)
249,000 highway miles
***Replaced @ 247,000 miles - Upper intake plenum, thermostat, radiator hoses, oil pan gasket, coolant, fuel filter, air filter, lower intake gaskets, CTS, PCV, plenum pressure sensor, sparkplugs, wires, lower intake elbow, oil & filter (twice after repair)***

I might be wrong but I would have to say no. IT reads how much fuel in the tank.

no, it wont' affect your mileage in anyway.

as long as you dont mess anything up that wasnt messed up to begin with <like fuel lines and stuff >

If your gauge reads ful all the time, it might be the hot wire grounding out, poke around