You don't mention what model year of Mercury Mountaineer
so I was looking at various model years
The Owner Guides show that the Motorcraft BXT-65-650 battery was used
most
( that's BCI group size 65 , 650 cold cranking amps )
* some model years have an 850 cold cranking amp battery shown as the
optional battery
According to the 2003 Mercury Mountaineer Owner Guide : Both the 4.0 liter SOHC , V6 and the 4.6 liter V8 engines have the Motorcraft BXT-65-650 battery ( that's BCI group size 65 , 650 cold cranking amps )
On a 1997 Mercury Mountaineer : It came from the factory with either the Motorcraft BXT-65-650 battery ( or the optional Motorcraft BXT-65-850 battery ) ( that's BCI group size 65 , 650 or 850 cold cranking amps )
You don't say which model year of Mercury Mountaineer but they have all used the ( BCI group size 65 battery ) such as the Motorcraft BXT-65-650
8"
The owners manual shows ( Motorcraft BXT - 65 - 650 ) That is Fords " top of the line " battery for your vehicle * that's BCI group size 65 , 650 cold cranking amps
See sources and related links below to lookup bulbs for any year mercury mountaineer.
Each remote takes ( 1 ) coin style battery ( CR 2032 ) or equivalent according to the owners manual
the four door speakers are 6x8 and the sob if you have one is 8"
The sub woofer size on a 1999 Mercury Mountaineer is 5 inches by 7 inches. Speakers are located in the front and the rear of the vehicle.
On a 2007 Mercury Mountaineer : Open the drivers door and on the end of the door ( or the latch pillar ) you will see an information sticker that shows the original size tires on the vehicle from the factory
21 U.S. gallons ( 79.5 liters )
5x7 in both front and rear doors.