We don't drive our cars a lot, usually 7-8K miles per year.

We just got my wife a 2017 Subaru Legacy. The dealer said we should do oil changes every 3k miles. However, it will take her 4-5 months to accumulate that much mileage. Should we go with every 3 months/3000 miles whichever comes first or what until she is near 3K miles?

I also just got a 2013 Hyundai Tucson with 78K miles on it. So the question is the same, should I wait until I near 3K or do it at 3 month intervals?

Car companies recommend 3000 miles for an oil change to cover their own arse, but it doesn't hurt the car at all. I check oil level twice a month, and look under the car for signs of leaks often. Highway miles are better than stop and go city miles as long sitting times isn't especially good for gaskets and seals depending on the local weather, especially in older models, and I change my oil every 5000 miles, depending on usage, and after road trips of more than a thousand miles.

I think its more important to check and change oil to keep clean oil in your car, and maintain proper levels. I wouldn't panic going over 3000 miles though, but for the sake of whatever warranty/contract you may have, do as directed/ or recommended. I would go with the 3K change, no matter how long it takes to get there.

I might change oil the first time at 3,000 but with the newer oils and modern engine design, 3,000 is not needed. I have a Honda CRV with 175,000 miles. I only go to HONDA and they recommended 5,000 miles. Newer Honda's don't have any recommended frequency, the computer determines driving style and conditions and shows a % gauge of oil life. Does your Owner's Manual show 3,000 or the dealer says.

1. Cars go a lot longer between oil changes these days.
2. Your car will compute time and mileage and tell you when it's due. Read the manual and find the button options on your dash.
3. I drive 2500 mpy. So I did wait 2 months past what the computer told me on my brand new van (it decided one year on a new vehicle trumped mileage, I think), and had mine changed just before winter, 14 months and just below 3000 miles.

So those are my variables, weather, time, and mileage. Others might be lots of dust and dirt in the air, steep hills, high speeds a lot, heavy loads, and very short trips.

You can probibly go 6 months between changes but don't go beyond 12 months if you don't drive it enough to hit the mileage factor. Reason isn't that the oil is worn out or dirty, but acids can form and accumulate over time with infrequent use.

Is that Legacy a 2.5L or 3.5L, Makes a difference. Here is what Subaru say about your oil

2017 Subaru maintenance schedule and new car break-in period (http://www.cars101.com/subaru/maintenance-2017.html)

If you are using synthetic oil it can be much longer

ScottGem - I hadn't even noticed that you asked the question. Now my response sounds kind of snooty. Maybe I should take that to heart for all my responses.

I saw nothing snooty

Thanks. On Facebook I get a lot of grief.

Between the owners manual and the dealer you have all the answers you need. However if you ask a question often enough somebody will give you an answer that may agree with you. Take your pick.

Nobody asked HOW you drive. Oil change intervals are based on HOW you drive and how many miles. If you do lots of cold starts, short trips and stop and go driving you must change oil more often even if it's synthetic. If you go gallengerbs link you'll see that the recommended oil change interval drops to 3M miles from 6M miles if you meet these conditions:

Note: with stop and go, hot/cold, hard, or severe driving, replace every 3,000 miles or 3 months whichever comes first #1

Almost 80% of city dwellers do severe driving and advice to extend oil change intervals is just plain bunk.

Whatever the factory service manual recommends, or whenever the oil starts to look dirty (black instead of translucent). Also, if the oil hasn't been changed in a while, let's say 6 months, its a good idea to change it then too. The additives in the oil that draw heat away from the engine degrade over time. It will still lubricate the engine, but it's ability to draw heat away from the engine will be reduced.

Full synthetic oil provides superior protection for parts and makes starting easier in cold weather. You can also drive a lot further between oil changes with synthetic vs conventional. Since it's also a newer vehicle, I'd recommend full synthetic if you don't mind paying for it. If not, half conventional-half synthetic is the other alternative.

If the vehicle is turbocharged, it's necessary to change the oil at much sooner intervals to prevent oil contamination. The turbocharger operates at very high rpm, some over 100,000 rpm. There are bushings inside the turbocharger that are bathed in oil. There is also an exhaust-driven impeller on one end, and compressor at the other end of the turbo that force air into the engine. The compressor floats on a thin film of oil, so having good oil is extremely important to the life of a turbocharger.