I have been tracking oil levels/consumption in the Sienna & Highlander across several OCIs. I have noticed that it does get worse as the OCI progresses. For both cars, the first 1000-2000 miles, there is very little. But towards the end of the OCI, the oil level does drop faster. I have seen this phenomenon more than once, for both those vehicles.
The last several oil changes, I have used 20 grade oil in them. Both cars were originally 5w30, but were back-specced to 20 grade. With the Highlander, where I have seen consumption the greatest (just over 1.5 quarts in 5-6K miles), I'll move to a thicker oil next time I do change it. I have a ton of 20 grade oil in my stash, so I will probably want to use it up before moving the Sienna to a thicker oil, unless I see a big increase in consumption with that engine as well.
Now for my question: Does this non-linear consumption point to any one thing as being the cause of oil consumption (as in seals or piston rings)?
The last several oil changes, I have used 20 grade oil in them. Both cars were originally 5w30, but were back-specced to 20 grade. With the Highlander, where I have seen consumption the greatest (just over 1.5 quarts in 5-6K miles), I'll move to a thicker oil next time I do change it. I have a ton of 20 grade oil in my stash, so I will probably want to use it up before moving the Sienna to a thicker oil, unless I see a big increase in consumption with that engine as well.
Now for my question: Does this non-linear consumption point to any one thing as being the cause of oil consumption (as in seals or piston rings)?