Frequency of oil changes for low mileage cars -

I maintain three vehicles, including a pickup, all of which are driven less than 6k miles/year. My pickup is driven only about 2k miles/year. I generally change the oil and filter every 3k-4k, or 4 months, whichever comes first. Always, the time comes before the miles. Am I wasting money by changing oil so frequently? The owner’s manual for all vehicles recommend 5k-10k miles per change (depending on vehicle), but I figure that, over time, the oil is breaking down even tho I’m not putting on the miles.

Comments, please?



Yes, you’re wasting your money. I change the oil in my two vehicles at 5,000 miles or once per year, whichever comes first, and I’m probably being too conservative. There were several years in which one of my cars travelled less then 5K miles, and I changed oil once each year.

I’m amazed that the oil companies have been so successful at convincing people their product “breaks down” while it’s sitting in an engine doing nothing. I don’t believe it for a second.

What do the owner’s manuals say? That’s a great place to start. You should not change the oil any more frequently that 6 months and I wouldn’t let it go any longer than 9 months.

I agree with JT. I would suggest rechecking that owner’s manual. It should say XXX miles or XX months which ever comes first. It also likely will have a second set of number for severe conditions and many people fit that category. Do no less than the owner’s manual recommends and I would not bother doing more. It really will not help and in some ways it may actually hurt.

I don’t agree. The low mileage thing can occur two ways. One is if a car sits a lot and is not driven. In this case once a year is probably OK. The other is if you do very short trips. Under a few miles. In this case, the oil needs to be changed often, because it gets dirty very quickly due to not getting heated up. Also, stop and go driving in town is very hard on oil. Or very dusty conditions. Or very heavy towing.

Agree with Melott that this is a case of “severe service” due to the short trips. Your driving is vey similar to my mother-in-law’s. I would recommend a seasonal change; Once on the fall and once in late spring, dividing the year in half. Typically, that would need 5W30 in the fall and 10W30 in the spring. With this arrangement, which my mother-in-law faithfully follows, you are neither over- or under-maintaining.

If you only drive a few miles, but with long trips, one oil change a year would suffice; go with 5W30 synthetic. I did that when on lenghty assignments (3 months) out of the country,

I would probably go at least six months if you don’t have any specific time interval for your car. IMHO, 4 months is not necessary.

How do you know that it is severe service. I would go for the full mileage if I put on 6 K/year if it were at least 20 miles per trip, maybe less. He could be putting it on at 100 miles a pop for all we know.