My family and my mom needed to make a trip from Russellville, KY to Indianapolis, IN over the weekend to my aunt's funeral who passed away last week. This is under a 300 mile drive and we decided to go in mom's '99 Mercury Grand Marquis. Since mom doesn't drive I was at the wheel and decided to see what I could get out of a full size car with a V8 engine. I filled up here in Russellville (topped off), drove to Indianapolis all 4 lane or interestate, drove approximately 30 miles of city driving/funeral procession driving inside the city of Indianapolis, drove back to Russellville, and topped the tank back off at the same station. The low fuel light came on about 25 miles prior to getting back to the gas station where it all began. Total trip was 540.9 miles on 17.181 gallons of gas for 31.48 MPG. Wish I knew what the mileage would have been without the 30 miles of city driving. This was accomplished by setting the c/c at 55 MPH and doing my best at timing out traffic lights in the Indianapolis area. This was my dad's car prior to his death and he had told me he normally got 28-29 MPG on the highway at speeds of 65-75 MPH so I just had to see what I could do with it. With the c/c set at 55 the total trip length was about 5 hours each way. Both on the way and on the return trip I probably never had to disengaged the c/c more than 6 times while on the 4 lane and interstate highways including interstate city driving in Indianapolis, IN and Louisville, KY. Pretty easy trip just sit back and steer.
Great! I was always able to do over 30 in my grandfather's Grand Marquis. They are geared really tall for the highway.
I'd driven the Grand Marquis on short trips, but this was the first time I'd ever taken it on a road trip and was pleasantly surprised with 31.48 MPG. Gas for the trip was just over $57. if I remember correctly. That's better mileage than I got with my '78 MG Midget when I had it and it's a much more comfortable ride than the MG was, just not as much fun to drive.
Ever since the full size Fords were fuel injected, they have gotten similar mileage. I remember taking my great aunt's 88 Lincoln Town Car (Fuel injected 302) on trips, and it did almost 30 in the mountains of Pennsylvania.
Mom's last car was an '88 Crown Vic w/ 302EFI AOD. Drove her to Calgary once; about 600 km one way. Figured we wouldn't go the distance so filled up along the way. Pump cut out much too soon (in my opinion); I kept trying to squeeze more in & eventually gave up; it was FULL. Over 31 mpg (yes, converted everything to Imperial) on that leg. The last big Fords/Mercurys were well built, dependable, comfortable & economical cars.