I have a 2010 Mercury Grand Marquis LS Ultimate Edition 4.6 liter flex fuel with 69922 miles
I inherited this car when my mom passed September 3,2021. It was her baby and she did everything she was suppose to do oil changes every 3,000 to 4,000 miles. She had the trany flushed a year before she passed with a coolant flush and fuel filter replacement all around 50,000 miles. I am going to be doing more driving than she did. She bought it used from a dealership where a member of our church worked for years. It was her second one and she bought it in 2016. I can not get a consistent answer from the 5 Ford dealerships I called about oil changes,rear differential fluid changes, trany fluid changes,spark plugs and other things that are not listed in the owner's manual. I know when to do these things on my 66 Dart and 68 Polara. I know from watching your videos you cannot trust dealerships and probably not the maintenance intervals for oil, trany and other fluids in the owner's manual. I would like to get at least the 200,000 or 300,000 miles I have heard people get out of this car. Thank you for your time.
Best Regards Michael
oil changes,rear differential fluid changes, trany fluid changes,spark plugs and other things that are not listed in the owner's manual
these were never in the owner's manual. Ford provided a separate "Scheduled Maintenance Guide" with the vehicle.
https://www.manualowl.com/am/Mercury/2010-Grand%20Marquis/Download/4655
My mother was meticulous about the car,maintenance records,any paper work and manuals. They are all here, the owner's guide,scheduled maintenance guide,warranty guide and the tire warranty guide. As I stated before from watching Scotty's videos you don't trust dealerships and probably not what is in these guides. I saw a video where he recommended trany fluid every 30,000 miles if I remember correctly and I do not remember what he recommended for rear differentials. I want to keep this car as long as possible. It is a great car and I just want to do things in a timely manner not guess and take the manufacturers recommendations. Again as I stated before I got different answers from each dealership I called. If you can't get the same answer more than once how can you trust what is in the guides.
I got different answers from each dealership I called.
If you ask 10 different people, or 10 mechanics, you will get 10 different answers. That doesn't mean 1 is right and 9 are wrong, because there is no one-size-fits-all solution. Wear & tear depends on the type of driving you do. It's not an exact science and the precise interval doesn't matter that much, as long as you perform reasonable maintenance. Following the normal schedule in the "Scheduled Maintenance Guide" will be fine for most people. For extra brownie points and you really want to baby your car, then go with the heavier service schedules.
all city driving, or dusty roads, and hot climate: heavy wear & tear
mostly highway driving: light wear
my general opinion:
engine oil + filter: 5 to 7k miles
automatic transmission oil + filter: 50-60k miles
rear axle lubricant: 60k-70k
YMMV