'01 GM Gas Gauge
I'm taking my grandfather's Grand Marquis on a cross country road trip. I had a quick question about the gas gauge. Is it top heavy or bottom heavy? The computer says I'm getting 20.9 MPG after going ~250mi with only a quarter tank left. 90 miles or so to empty. If the tank is a 19 gallon tank, that's only 17.8mpg, it seems off.
On a side note, the car has 70k miles on it. I think I'm going to change the fuel filter, Air Filter, PCV and Clean the MAF. Is it worth it to change the plugs? Will it help the MPG?