Maintaining a 4R as a second vehicle

[Jester4kicks]

Hey all. Back in Aug of last year, I decided to get a new car but keep the 4R around for offroading and such. Since then, it hasn't been putting on many miles, just sitting in the garage most of the time.

Now I'm wondering how this affects the maintenance schedule, and how to keep the battery from dying if it sits there for a month or more.

It's currently sitting at just over 91,000 miles. My last...

...Oil change was at 86,000 on 1/18/2014. (Mobil 1 5w-30 Synthetic)
...Gear oil change was at 64,500 on 9/18/2011. (Mobil 1 75w-90 Synthetic)
...Coolant flush was at 64,355 on 9/6/2011. (Whatever the shop used)
...Spark plug swap was at 64,340 on 9/5/2011. (NGK LFR6C-11)

Obviously things like the air filter, tire rotations, etc are more mileage-based than time. But what about fluids, plugs, and other things I may not have done yet? Is there a maximum amount of time I should go between those things, regardless of miles? (Oh, and I almost never tow.)

Are there any other "best practices" for keeping a mostly-idle vehicle healthy?

Much appreciated!

 

[NuclearN8]

I would
-Drive it at least once a month to cycle the actuators (assuming it's a 4x4). This also prevents flat spots in the tires (also check tire air pressure once a month while out on your drive)
-The next time you drive it, fill it up with premium fuel (ethanol free if possible), dump in a large bottle of fuel system cleaner (techron or seafoam) and drive enough to get it through the fuel system (5-10 miles at highway speed should do it)
-Get a trickle/ float charger on the battery for when it's parked in the garage

other than that you should be good to go.

If doing a bunch of short drives I would change my engine oil and filter more frequently to keep the oil as condensation free as possible

 

[Jester4kicks]

Thanks, Nuclear.

The plan at this point is to drive it to work once every 2-3 weeks. That's about a 20-minute drive, one way, with both surface streets and highway. I can also throw it into 4wd for the last 5 minutes on the surface streets to help keep it in shape.

As for the fluids, since posting the thread, someone told me that those are all use-based and shouldn't go "bad" just sitting there. My plan is just to replace those when the odometer says so.