Oil/Filter Change 2007 Jeep Liberty?

The oil additives don't break down just sitting, if they did the oil would need to have a shelf life date. The amount of water that can condense on the inside of the engine is very small because air doesn't circulate through the crankcase and any water that does condense will evaporate as soon as the engine comes up to operating temperature. You aren't driving your jeep enough, cars and trucks are made to drive not to sit in the driveway. You should drive the Jeep at least once a week at least long enough to bring the engine up to operating temperature and far enough to get the tires good and warm.

If you don't drive many miles you should be using synthetic motor oil that has no 3 month time limit for needing to be changed. Synthetic oil I would change every 5,000 miles.

Certain additives can react with oxygen and there is plenty of it in the air, however the air inside the crankcase is typically not circulating, so any reaction will take many months. As for condensation, depending on your climate, it can happen inside the crankcase even without the heating and cooling of the engine. But the water content will quickly boil away if operated for an extended time at operating temperature. Even if the engine temperature is only 195F, oil temperature is typically 15 to 30 degrees higher, which is enough to boil off water. The condensation only becomes problematic if the engine is never allowed to reach operating temperature.

So my opinion, (And this is just my opinion, other opinions will vary), is that you do not necessarily have to change your oil at this time. I always change my oil in all of my vehicles every January regardless if I just had it changed. January is my personal maintance and general repair month. I do all my oil changes, lube ball joints and tie rods, check brake pads, change air filters (including cabin air), and do any repairs that I've been putting off (I do the same for the house in January as well, repairs, filters for central HVAC, check smoke detectors, etc). So basically, the oldest my oil gets is 12 months, even on a vehicle that I rarely drive.

I find nothing wrong with Passive Agressive's suggestion about a 2 year interval on an engine that is rarely used, I'm just suggesting the 1 year interval because that's what I'm used to. An oil change is not that expensive when you take into consideration the change interval, 1 to 2 years.

Have a similar situation with a vehicle we now drive less than 1000 miles a year. My garage finally suggested switching to synthetic oil and changing every 2 years. Also said that when we do drive it, to drive long enough to get fully hot to "burn" any contaminants out of the oil . . . . so we give it a go on the freeway for a few miles when we have it out. Oil is still clear at the end of 2 years, so even that might not be necessary but the shop gives it a complete front-to-back inspection & maintenance so the oil is a small price to pay.

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