Severe or normal driving


I drive about 400 miles/month. The bulk of my driving (80%) could be called short trip. However my short trip is 2 miles downhill doing 30-40MPH merging followed by highway(65MPH) 2 miles where engine temp gets to normal whether 0F-40F nearly right away. I get off an 1-2 miles of two lights. Finally I go back.

Subaru does not specify definition of short trip that I could find. The car is a 2004 WRX wagon.

Severe oil change is 3.75months/3750miles and normal is 7.5 months/7500 miles. Changing the oil at 1200 miles oil old/4mos seems a bit early. I was thinking 2400miles/6 months… Opinions…


A test done on New York City cabs found that oil run under extreme conditions did not start to lose its viscosity until 5000 miles. This was done with standard oil. Synthetic oils will stretch your time between changes to near 10000 miles.


I would not by any means consider your description to be severe service. But all such opinions are of limited use because the definition is so vague and the schedules have so much built-in leeway.

In your shoes I would simply change the oil twice a year, spring and fall, and give it no further worries. Use these bi-annual car weekends for other maintenance and inspection such as wiper blades, tire rotation, waxing, vacuuming, and whatever else needs occasional attention. Then drive it carefree for six months.


I was thinking 2400miles/6 months…

I’m thinking that’s good thinking.


The short trips make it severe in my book, despite the speed. I don’t think that you should use mileage as a criterion unless you exceed 3750 in 4 months. If you use time only, change your oil every 4 months. At this point you are out of warranty, so 6 months is not out of the question.


You can safely go six months and don’t bother counting miles.


I am actually have 15mos/12k left of powertrain warranty left over. It only has 48k miles on it, 22k of it put on in first 9 months of life.

I guess its really 2 oil changes vs 3 oil changes/year with each change only $25/each at dealer.


JMHO, but your driving falls into the severe category as about 99% + of all driving does. I would agree with the 2400/6 months or 3750/3.75 months or somewhere in between.

For what it’s worth I’ve had to replace a couple of engines in Subarus that were so far gone they were not even rebuildable due to the oil change habits of the owners. In those cases, none of the cars even had 30k miles on them yet and were trashed due to the extremely short hop driving habits the cars were suffering from.
Of course, in every case the owners went ballistic and blamed everyone on the planet except themselves…