Using synthetic motor oil, how long do you run between oil changes. I switched to Mobil 1 for one oil change from 18K miles to about 22.5K miles.
Drained and filled up with Amsoil 5W 30 with Amsoil filter also. Ran to 29K miles and changed the filter only (with another Amsoil) . Now have 31K and some change, getting close to the 10,000 mile mark on this oil and plan to change soon. Any other synthetic users running 10K miles on a oil change?

 

I don't recommend going that long without a UOA. A UOA will tell you how the oil is doing; if there are any issues and also provide you a baseline of how far you can go on that particular oil, or, if you need a filter change and top off at the half way mark to get to the desired OCI. Example: I did a UOA at 6000 and found out that I had dirt leaching into the engine. Corrected the problem, changed the oil, and now I am confident that I can get to my desired OCI of 7500K without a problem.

Pedro

 

I use mobil 1 and switch it every 7500 miles. I don't bother changing the filter in between either.

 

I am curious what "UOA" is, and I am also intrigued about going over 7K miles on the oil changes. I use synthetic as well, but change the oil and filter approximately every 5k miles. I live in the Seattle area, so I don't expect that the conditions are very harsh here. Am I just a chump for changing my oil sooner? How confident are you with long change intervals?

 

UOA=Used Oil Analysis. Analysis of all the elements in your used oil. A UOA will tell you if you have any issues, i.e., dirt ingestion, current iron, lead levels, coolant leak, fuel in oil, flash point of oil, if the oil has sheared or thickened, and if your oil is up to the task to go further. Like I said before, it helped me find an dirt ingestion issue that I was unaware of. I was then able to fix it (one rear bank sparkplug that was extremely loose and letting dirt in and letting oil get in the spark plug chamber).

Pedro