Should I change car engine oil by milage or by months?

Generally speaking, people suggest to change car engine oil every 3000 miles or every 3 months.





I have a car that I don't drive much. I drive about 1000 miles in 3 months and it's been little over 3 months since my last oil change. So, in such a case, should I change this car's engine oil now since it's been 3 months since the last oil change? or should I wait until I reach close to 3000 miles even if it means waiting another 5 to 6 months?Should I change car engine oil by milage or by months?
The reason you change your oil is to maintain good viscosity which keeps metal parts from touching and creating friction. Viscosity is lost in oil as it is heated to great degrees and then cooled. So with that said it's mostly the mileage that you want to concern yourself with but even so I wouldn't let oil sit in my car for over a year regardless the mileage. 3 months of being in the car isn't a good reason to change your oil.Should I change car engine oil by milage or by months?
Once the oil container is opened, it starts to age. As it ages, the additives are lost.


Also one function of oil is to emulsify the water in the system, so if the emulsifier is all used up or died due to age it no longer protect the engine from condensation (water).


This water will be at the bottom of the oil pan and be the first thing that the oil pump picks up. While I know water is a good lubricant it is not some thing I want in the valve lifters (or main bearing). It does not help the rings either.


The end result is a short lived engine. But with your driving habits you will never notice it.


This in one reason that a low mileage car is not a good gamble and why I will buy a high mileage car before a low mileage one.


Change by months.
Changing your oil every 3000 miles is a scam. Generally car manufacturers recommends changing oil every 5000 miles. Read your service manual.


Why would oil go bad after 3 months? It can sit on the shelf in a store for years and still be fine.


I restore old cars for a hobby. I have a 1935 Ford truck with 7000 miles on it and have changed the oil in it 3 times over the last 12 years. 1st time was after a few hundred miles to clean out the assembly lube. 2nd time was 3500 miles and I just changed it again last week. The oil was still clean.
I've got the same problem and I change the engine oil once a year or 9,000 miles, whichever comes first using http://www.mobiloil.com full synthetic oil. Note that you can't decide when a fluid needs changing by ';looking at it';. You have to change it before any visible signs of deterioration are apparent. That's what ';oil testing'; is all about.
Correct mileage or quarterly. It's good insurance for your engine.


Stop and go driving is not the best for circulating oil.





Also, tires and battery age, even without mileage.





My car recommends 5, 000 mile oil changes. I don't drive much so I change at 3,000.
mileage...unless the low miles you do are hard driving, thrashing the nads off the engine etc especially if you only do short trips so the engine never warms up properly
MIND THE MILEAGE.NOT THE MONTH COUNT!
oil is good for evey 3000 miles so no you shouldn't have to. I change my oil when it turns black.