I bought an ‘05 Grand Marquis a few weeks ago. It has 73k miles. After my mechanic gave it a once over, he told me everything looks good. I’m getting terrible gas mileage though. Something like 12 city and 20 highway. Is this normal? Anything I could do to improve it?
>>27775415In my '00 Grand Marquis I got like 24 highway. Don't remember city, but it was more than 12 although I rarely used to ac. Buy a k&n air filter
>>27775439I have had the AC blasting every time I drive because it’s been 100 degrees or more every day. I guess that could be affecting the MPG.I will definitely get a K&N. Guy who sold it to me put on a new one just before he sold it to me but it’s a cheap Fram from Walmart.
>>27775439Don't do this, get the most restrictive air filter you can find. Better yet, install a restrictor plateYou'll lose power obviously but if gas mileage is your goal manifold vacuum is the name of the game
>>27775415>buy landbarge with V8>surprised when it gets bad fuel economy
>>27775415I have a crown vic with the 3.27 Trac Lock rear end. I drive with a heavy foot, mostly city, usually get 13-14 mpg mixed.
>>27775415>12 city and 20 highway.>Is this normalNo. Try to keep your speed between 35-70mph. It's the real sweet spot for these since you're into O/D(depending on gearing, 2.73 cars aren't into o/d until 43mph) but not fighting a lot of extra drag. I have 3.27s like this guy >>27775502 but I see more highway and I also drive with a light foot.
>>27775415No. If you aren't making short hwy trips or driving over 70, check:MAF Plug gap Air filterCoolant temperature (scantool)Ford gauges are not representative of actual data. I had a thermostat stuck open and was getting terrible milage(8-14). Didn't know because after 10 minutes the gauges just sit in their normal range position. I also bought multiple new thermostats that opened at 160 before getting one that opened at the advertised temperature.
>>27775415Sounds about right, I remember my crown vic was similar and I think it had 3.27 rear axle ratio.
>>27775415My dad has a grand marquis, they are fun to drive cars cause of RWD. Bad gas mileage can be a number of things, from a bad oxygen sensor to a vacuum leak. Get a scanner up to it that reads real time data and youtube how to interpret it, you are probably running rich.
>>27775502that's the same gear ratio the nyc taxi package vics had. they did decent on gas for what they were.
>>27775415Had an 04 i bought with 49k miles with the HPP and 3.27 rear gear, averaged 19mpg and it was mostly freeway at 80-85mph over 60k miles.
>>27775977Ethanol free fuel back then too
>>27775415Something is wrong. Change spark plugs and mass airflow sensor. I have a blown plug in my 09 even without it fixed right I still get 15ish mpg in the city. But yeah anything over 20 on the highway is considered exceptional
