Why 6000 mile oil/filter changes?

One of the negatives when we switched from Honda to Subaru was the shorter oil change intervals. Honda’s system gave oil changes based on usage with their oil life monitor, so high mileage highway drivers would typically go 10K miles between changes while city drivers would change their oil sooner. Our last Honda was a 12 Odyssey, 10K mile change intervals based on the oil life monitor, never used any oil or had problems in its 141K miles with us.

Similarly, my 14 Sierra had an oil life monitor that ended up being 7,500 mile change intervals, never used any oil in its 177K miles with us.

The shorter Subaru intervals are inconvenient for long trips because I have to find a Subaru dealer on the road to change the oil. So far I’ve only had to do that on one trip, and was fortunate to find Stivers in Atlanta to change the oil in the middle of a summer trip. I’ve read too many stories on this forum about non-Subaru dealers pulling the wrong plug doing a simple oil change, so for out of town trips I feel better going to a Subaru dealer.

This summer we’re going to change the oil just before leaving on our trip and try to keep it close to 6K miles so we can make it back to our home dealer for the next oil change. Part of the reason we looked at the 23 Pilot was for the longer oil change intervals, but there were many more factors in favor of Subaru so we ended up with a 23 Ascent.

The comments above about the oil dropping out of viscosity with the turbo in about 3K miles don’t surprise me. This was true with a research project I did with Valvoline back in 1980 where most were running 10-30 or 10-40 and 3K mile change intervals. The typical 10-40 would degrade to a 10-30 after about 1,000 miles, but there were some oils that held their viscosity if they had enough nickel in their formulation.

Oils and engines have come a long way since then, so I guess I should be grateful for a 6K mile change interval instead of the 3K mile intervals from 40 years ago. I know there are many who still use shorter intervals, but I’ll be sticking with whatever the manufacturer recommends.

I am always surprised by people who post dismay about the low oil light coming on in their Subaru because they never check the oil. I check mine (as well as coolant, brake fluid, etc.) very frequently with a new vehicle, and gradually increase the interval as I gain more confidence in the vehicle. On road trips I’m checking every day, which means every 300-600 miles because I know sustained operation can be stressful on an engine, though perhaps less stressful than a lot of short trips. I will confess that with our Hondas and the Sierra those under hood checks did become less frequent when it became obvious they never used any fluids, and that is the standard I’m hoping our Subarus live up to. The Outback is at 72K, the Ascent is at 3K soon to be 12K during the summer, so they both have a long ways to go.

Source link

We will be happy to hear your thoughts

Leave a reply